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Spyder 97 GST Spyder P0300 and Jumpy Tachometer.

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ZubUchiha

Proven Member
81
7
Jul 30, 2021
Riverside, California
Hey y’all, I Just got a 97 gst spyder and it has a p0300 code. I changed the spark plugs and the check engine didn’t come on but halfway of driving it back home, check engine came back on and it started misfiring. When I start to accelerate it would feel as if the clutch was slipping, and the entire car would start to rumble and shake hard, but this would only happen sometimes. Another problem is that when I accelerate the rpms fluctuate up and down like it’s lagging as it’s going up, but when it’s in neutral, it goes up and down smoothly. The temperature gauge would also start to go up slowly past the halfway mark. Another question I have is when the car is idling in neutral and not moving, the rpm’s will drop below the normal range the car will vibrate as if it’s about to stall, any reason why this would be? My reader only shows this code and none other. Any help would be appreciated.
 
Please fill out a vehicle profile. What maintenance have you done? Try a set of spark wires and give us more info on this potential overheat issue. Any symptoms? Smoke? Coolant loss?
 
Sorry about that, I just filled out a vehicle profile. I have not done any maintenance since I got the car, I have no knowledge of where to take it because I fear scam mechanics. When I got the car, I poured some 5W-30 oil into the engine, and some coolant into the coolant reservoir because I thought that was the initial issue, but it still continues to overheat. I will try a new set of spark wires, the current ones are the NGK blue spark plug wires, so I might just buy the same type again.

In terms of symptoms, the car will overheat when I start accelerating too high, but like I said, that's when the rpms will jump up very high, and the entire car will start to shake and rumble. The first day I got the car, on the way back, the car would overheat when I would press on the gas, but letting go of the gas would make the temp gauge fall back down slowly to right above the half meter mark.

There is no visible smoke coming out the exhaust or engine. I think there may be a coolant loss, but then again, this is my first car so I don't know how fast the coolant is supposed to go down. I filled it all the way up a couple days ago, and I think it's about to be at the half mark line now. There are no leaks so I am not sure if it's eating up a lot of coolant or not. I will have to post more photos and videos so you understand what the issue is.

Right now, the main issue is the misfiring, so I'll get the spark plug wires and see how that goes, but I think it may be more than that. Hopefully not.

Also, I just noticed another thing while looking at the engine bay, there is an extra rubber tube connected to the coolant cap, i tried to search it up for this car, or any car in general, and I think it is an overflow tube that send coolant back into the reservoir when the radiator doesn't need it. Maybe that could be a reason for loss of coolant, but I am not too sure. I also don't want to stick it in the wrong place, so I'll wait until someone gives me the go on where it should go.

Another thing I would also like to point out, that I just noticed is that, when I try to turn the car on, there is a loud screeching sound that comes up, but when the car turns on completely, it goes away. Some times it continues to screech as the car is on, but it goes away in about 5 seconds after it turning on.
 
Did you add coolant to the reservoir or did you remove the coolant cap or both? You should not be losing any at all.
 
Did you add coolant to the reservoir or did you remove the coolant cap or both? You should not be losing any at all.

I did not remove the coolant cap, only when i needed to fill up on coolant of course. I filled it all the way to the top which I don't think I should have done, I believe I forgot to fill it up to the full meter line. I don't know what the extra rubber tube is doing hanging loose. It is connect to the other side of the coolant cap. Where should I put that?
 
Pictures are worth 1000 words. When the car is cold you need to check level under the coolant (radiator) cap. Not the reservoir. And no you should not have filled the reservoir up.
 
Pictures are worth 1000 words. When the car is cold you need to check level under the coolant (radiator) cap. Not the reservoir. And no you should not have filled the reservoir up.

As soon as the car completely cools down, I will snap pictures and a video of what it looks like, for now, this is what the engine looks like. The engine is just slightly warm right now.

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Also, I just noticed another thing while looking at the engine bay, there is an extra rubber tube connected to the coolant cap, i tried to search it up for this car, or any car in general, and I think it is an overflow tube that send coolant back into the reservoir when the radiator doesn't need it. Maybe that could be a reason for loss of coolant, but I am not too sure. I also don't want to stick it in the wrong place, so I'll wait until someone gives me the go on where it should go.
From the factory, the coolant reservoir has two hoses that attaches to the cap; one that goes to the thermostat housing assembly (right), and the other is an overflow tube (left).

In regard to your idling/RPM issues, my first thought was to maybe check your mass airflow sensor. A problem with that sensor can cause a lot of issues.

Other than that, your engine bay looks a lot better than mine when I first bought it! Oh, and welcome to the DSM community!!
 
From the factory, the coolant reservoir has two hoses that attaches to the cap; one that goes to the thermostat housing assembly (right), and the other is an overflow tube (left).

In regard to your idling/RPM issues, my first thought was to maybe check your mass airflow sensor. A problem with that sensor can cause a lot of issues.

Other than that, your engine bay looks a lot better than mine when I first bought it! Oh, and welcome to the DSM community!!
Where should the overflow tube go? Is it supposed to hang loose like that, or should it be attached to something?

I will check my mass airflow sensor, but do you have any tips on how to check it? I will do my own research, but I would like to have that one-on-one to make sure I am doing it correctly, and what exactly should I be checking for? I should first figure out where it is.

Thank you a lot!! I am excited to be a part of the DSM community. As far as the car itself, I need some advice on what I should do in regards to the title transfer, registration, etc. So essentially, the registration has been expired and needs to be renewed, that's no issue. The title also needs to be transferred in my name which I will do as well. However, the issue is that, I don't think the car is smogged so in order for me to register it, it must be smogged, but I can't do that because of the check engine light that turns on after a bit of time when the car is turned on. My main concern it trying to make sure I get rid of that check engine light so that I can get it smogged and complete the full registration. Any idea on what I should do and where I should start?

Just for reference, I have very little mechanical abilities, I am completely new to working on any car in general. I have no knowledge on how to work on cars, but completely willing to learn.
 
As soon as the car completely cools down, I will snap pictures and a video of what it looks like, for now, this is what the engine looks like. The engine is just slightly warm right now.

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Your hoses are correct. Your overflow is definitely too full and it looks like straight antifreeze. Is it duluted?
Go after basic maintenance first. Fill the coolant at the radiator cap, likely get a new cap too. I would pressure test the coolant also. Might point out some leaks. If you are down on coolant in the engine it will overheat. There is likely no point chasing other problems until you fix this one.
Yiur best friend would be a factory service manual also. NOT a Haynes manual.

Where should the overflow tube go? Is it supposed to hang loose like that, or should it be attached to something?

I will check my mass airflow sensor, but do you have any tips on how to check it? I will do my own research, but I would like to have that one-on-one to make sure I am doing it correctly, and what exactly should I be checking for? I should first figure out where it is.

Thank you a lot!! I am excited to be a part of the DSM community. As far as the car itself, I need some advice on what I should do in regards to the title transfer, registration, etc. So essentially, the registration has been expired and needs to be renewed, that's no issue. The title also needs to be transferred in my name which I will do as well. However, the issue is that, I don't think the car is smogged so in order for me to register it, it must be smogged, but I can't do that because of the check engine light that turns on after a bit of time when the car is turned on. My main concern it trying to make sure I get rid of that check engine light so that I can get it smogged and complete the full registration. Any idea on what I should do and where I should start?
There are a million reasons for a check engine light. Let's fix the oveheating first. Do you know how to fill coolant etc?

Just for reference, I have very little mechanical abilities, I am completely new to working on any car in general. I have no knowledge on how to work on cars, but completely willing to learn.
Do you have basic mechanical aptitude? Work with tools etc?
 
Your hoses are correct. Your overflow is definitely too full and it looks like straight antifreeze. Is it duluted?
Go after basic maintenance first. Fill the coolant at the radiator cap, likely get a new cap too. I would pressure test the coolant also. Might point out some leaks. If you are down on coolant in the engine it will overheat. There is likely no point chasing other problems until you fix this one.
Yiur best friend would be a factory service manual also. NOT a Haynes manual.
The coolant is diluted. The type I got was a 50/50 so it's already diluted. I know how to fill coolant from the coolant reservoir, but not from the radiator cap. I also don't know how to pressure test or what I need for a pressure test. I will look at the factory service manual that's provided on this website, but what exactly should I be looking for?
There are a million reasons for a check engine light. Let's fix the oveheating first. Do you know how to fill coolant etc?
I know how to fill coolant from the reservoir, but not from the radiator cap. Can you also explain why I might need a new radiator cap, what difference does a cap make? I also bought a OBD2 reader so the check engine light is because of the P0300 code which is random misfires.

Should I risk turning the car on if it makes that loud screeching sound, I don't want to potentially ruin the engine if the belt snaps.
 
The coolant is diluted. The type I got was a 50/50 so it's already diluted. I know how to fill coolant from the coolant reservoir, but not from the radiator cap. I also don't know how to pressure test or what I need for a pressure test. I will look at the factory service manual that's provided on this website, but what exactly should I be looking for?

I know how to fill coolant from the reservoir, but not from the radiator cap. Can you also explain why I might need a new radiator cap, what difference does a cap make? I also bought a OBD2 reader so the check engine light is because of the P0300 code which is random misfires.

Should I risk turning the car on if it makes that loud screeching sound, I don't want to potentially ruin the engine if the belt snaps.
When the car is cold you can take off the radiator cap and add coolant. The radiator cap raises the pressure in the system which raises the boiling point. Basic chemistry if you're familiar.
Let's start there.
Now as for belts check for tightness. The belt closest to motor is power steering and water pump, the outer belt is alternator. The ac belt is not seen in your pics. Basic test is try and twist it. Should go no more than 90 degrees. If bwlt is loose it could squeal. There are other possibilities but that's good for now.
 
Where should the overflow tube go? Is it supposed to hang loose like that, or should it be attached to something?

I will check my mass airflow sensor, but do you have any tips on how to check it? I will do my own research, but I would like to have that one-on-one to make sure I am doing it correctly, and what exactly should I be checking for? I should first figure out where it is.

Thank you a lot!! I am excited to be a part of the DSM community. As far as the car itself, I need some advice on what I should do in regards to the title transfer, registration, etc. So essentially, the registration has been expired and needs to be renewed, that's no issue. The title also needs to be transferred in my name which I will do as well. However, the issue is that, I don't think the car is smogged so in order for me to register it, it must be smogged, but I can't do that because of the check engine light that turns on after a bit of time when the car is turned on. My main concern it trying to make sure I get rid of that check engine light so that I can get it smogged and complete the full registration. Any idea on what I should do and where I should start?
Yes, the tube just hangs there. It basically is meant to spit out excess coolant.

And the mass airflow sensor is the big black piece that is right next to the air filter. It's got a plug going into the top of it.

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You can remove the air box and visually inspect the inside of the mass airflow sensor to make sure nothing is damaged in there.

Also, when I had a belt squeal it was because my alternator belt was loose. It was the same with my friend's non-turbo 2G, so that could very well be the cause of your squealing noise.

But yeah, just like what pauleyman said, start with the belt and the coolant and work your way up from there. Let us know how that goes 🤟
 
When the car is cold you can take off the radiator cap and add coolant. The radiator cap raises the pressure in the system which raises the boiling point. Basic chemistry if you're familiar.
Let's start there.
Now as for belts check for tightness. The belt closest to motor is power steering and water pump, the outer belt is alternator. The ac belt is not seen in your pics. Basic test is try and twist it. Should go no more than 90 degrees. If bwlt is loose it could squeal. There are other possibilities but that's good for now.
Awesome, thanks for the input. So here's an update. The engine was cool so I opened up the radiator cap, the coolant was already full in the radiator so I did not pour any more. The cap seems to look like it has just a little bit of gunk on there. If there is no point in cleaning it, then I will get a new cap.

As far as the belts, I took off the belt cover, so that I can get some more visibility down there. Of the three belts, none of there were really that loose. They all turned to 90 degrees like you said and no further. I am not sure if I came across the a/c belt or not. I also realized there was a piece of wires and metal that just was not screwed on to anything and just hanging there (as you can see in the video when I get a hold of it after reaching down to another belt). Those belts seems to be doing fine and are not loose, since I don't know when they were last change, I might end up replacing them anyways, so I don't know which belt was producing the screeching sound. The coolant seems fine from what I see, what other suggestions do you have that I should check. It could be an issue with the water pump, but I have to ask a friend to access his tools to open it up. It could be the reason why the engine is overheating, so I can only tell by opening it up. Mind you, the temp gauge increases when I get onto the highway and start to do 50+, but on the streets and when it's idling, it's at the half line. When I accelerate on the highway, the temp gauge increases, but drops back down when I let go of the gas.

This is all I have for now, let me know what I should do next. Thanks.

Awesome, thanks for the input. So here's an update. The engine was cool so I opened up the radiator cap, the coolant was already full in the radiator so I did not pour any more. The cap seems to look like it has just a little bit of gunk on there. If there is no point in cleaning it, then I will get a new cap.

As far as the belts, I took off the belt cover, so that I can get some more visibility down there. Of the three belts, none of there were really that loose. They all turned to 90 degrees like you said and no further. I am not sure if I came across the a/c belt or not. I also realized there was a piece of wires and metal that just was not screwed on to anything and just hanging there (as you can see in the video when I get a hold of it after reaching down to another belt). Those belts seems to be doing fine and are not loose, since I don't know when they were last change, I might end up replacing them anyways, so I don't know which belt was producing the screeching sound. The coolant seems fine from what I see, what other suggestions do you have that I should check. It could be an issue with the water pump, but I have to ask a friend to access his tools to open it up. It could be the reason why the engine is overheating, so I can only tell by opening it up. Mind you, the temp gauge increases when I get onto the highway and start to do 50+, but on the streets and when it's idling, it's at the half line. When I accelerate on the highway, the temp gauge increases, but drops back down when I let go of the gas.

This is all I have for now, let me know what I should do next. Thanks.

Apologies, completely forgot to attach the videos.

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Belt Part 1
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Belt Part 2
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Belt Part 2
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The twist method isn't valid on the cogged timing belt as it's not a friction driven belt.
As for the wires. Those would bolt down with the timing covers which you seem to be missing.
Does the car always maintain temp at idle? I would replace the cap as a matter of maintenance as they are cheap. Just how far up the gauge does it go?
 
The twist method isn't valid on the cogged timing belt as it's not a friction driven belt.
As for the wires. Those would bolt down with the timing covers which you seem to be missing.
Does the car always maintain temp at idle? I would replace the cap as a matter of maintenance as they are cheap. Just how far up the gauge does it go?
I am not quite sure what the timing cover is unless it's the part I took off in order to show the belt. I'll go in depth as much as possible about the temp, but it's quite complicated. When I initially bought the car, the temp would increase while i was test driving it around the city, however, I did not pay much attention to it. When I purchased the car and started driving it back home, the temp gauge started to increase and it would go all the way up 3/4 of the line from Hot to Cold. I started to notice that as I would take my foot off the gas and coast on the freeway while in gear, the temp gauge would start to decrease, but would drop down to about 2.5/4 of the line, so it would be over the half line but it would be below the 3/4 line. I figured it either didn't have coolant or the coolant was really old, so I pulled over to a gas station and bought some 50/50 coolant. I turned on the car and let it sit for a couple minutes and let the engine take in the new coolant. The temp gauge did go down, but as I entered the freeway again, it continued to rise again as I was accelerating and would drop as I would let go of the gas, since I had no other choice, I just continued to drive home while occasionally stopping for 10-15 min to let the engine cool down with the hood open, and then resume. However, now that I look at it, the temp gauge is at the half mark line when it is idling in neutral, and when I drive around on the streets, it doesn't get hot nor does the temp gauge go up, however, when I drive on the freeway or I guess exceed a certain MPH, the temp increases. For this experiment, I will continue to take the car out tomorrow, record the temperature at idle, on the streets, and on the freeway, and take note of how much change exactly occurs because the temp gauge doesn't increase nearly as high as it would on the day I drove it back home. I'll make sure to take note of all three instances and record photos and videos for you guys.

I will also go to Auto zone and get a new cap. I watched some videos and I see how the cap works now, I understand the mechanism behind. I initially thought it was just a cap, so I was unsure of how it would build pressure, but the spring mechanism is what helps it build pressure until the safety valve opens, sending it back into the reservoir, allowing the reservoir to send coolant back into the radiator, allowing the process to repeat. Thanks again. I have a strong feeling the water pump might be clogged or really dirty which is why the engine overheats since it can't get enough coolant. I don't suppose there is any leakage or loss of coolant, and now that I think about it, since I topped the reservoir out, the overflow tube might have excreted the excess coolant in the reservoir tank that way it has space for coolant to enter the reservoir again. This is just my thoughts for now, but I am open to any interpretations and ideas. I will see tomorrow what belt is loose, and as Hellaman-99 said, it could be the alternator belt.

As far as overheating goes, I will make sure the car is still in the condition that I think it is, because if the temperature does not increase while on the streets or freeway and stays at the half line, then I think it might be safe to assume that it is not a main issue, and we can rather focus on the random misfire p0300 code.

Let me know any ideas/thoughts you have and if there should be anything I can check and I'll work my way up from there. Thank you!

I would like to point out one other thing. Since the cause of misfires is dependent on either the fuel, spark, or oxygen, I think the spark might have something to do with this. I can try and explain why and would appreciate any interpretation on this. While looking at the mass airflow sensor and intake (which the intake is clean, but haven't looked at the MAF since I need the right tools to open it), I noticed something very wrong with the battery.

Here is the video: DSMtuners is being buggy and won't let me upload it with my previous post, I don't know why.

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And here are photos of my intake, which is in pretty good shape, and another thing I wanted to know was if this flat part was normal or if this is something abnormal with the car.

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UPDATE:

I replaced the battery terminal with a new one, upon starting up the car (NOT turning it on), the transmitter produces a 12.5+ voltage. When I turned the car on, it produced a 13.5-13.7 voltage, which was better than before because just starting up the car would produce a voltage of less than 12.

I also bought a new radiator cap, so I am waiting for the engine to cool down to replace it.

I took the car out and drove it in around my neighborhood for a few minutes, doing a few loops, the RPMs still fluctuate as if it is lagging, however, there is no check engine light that has turned on. I am not sure if the RPM gauge is just not working correctly or if it's connected to the lack of power the car is producing due to the misfires, however, it is not showing a check engine light and temperature has remained at the half marker line.

Will update as follows. And will post a video of what the RPMs look like when I am accelerating.

UPDATE:

I replaced the battery terminal with a new one, upon starting up the car (NOT turning it on), the transmitter produces a 12.5+ voltage. When I turned the car on, it produced a 13.5-13.7 voltage, which was better than before because just starting up the car would produce a voltage of less than 12.

I also bought a new radiator cap, so I am waiting for the engine to cool down to replace it.

I took the car out and drove it in around my neighborhood for a few minutes, doing a few loops, the RPMs still fluctuate as if it is lagging, however, there is no check engine light that has turned on. I am not sure if the RPM gauge is just not working correctly or if it's connected to the lack of power the car is producing due to the misfires, however, it is not showing a check engine light and temperature has remained at the half marker line.

Will update as follows. And will post a video of what the RPMs look like when I am accelerating.

Here’s a video of what my RPMs look like. It looked way worse before, but now when I accelerate between 0 and 2 rpms it goes up smoothly, but as I accelerate past it, it starts to get jumpy. In the video, pay close attention to after I make the left turn, that’s when you see the rpms get jumpy.
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I’d also like to update that I threw on the new radiator cap and new battery terminal as I stated before.
 
Here’s a video of what my RPMs look like. It looked way worse before, but now when I accelerate between 0 and 2 rpms it goes up smoothly, but as I accelerate past it, it starts to get jumpy. In the video, pay close attention to after I make the left turn, that’s when you see the rpms get jumpy.
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I’d also like to update that I threw on the new radiator cap and new battery terminal as I stated before.
Does the car run funny when the tach jumps?
 
Does the car run funny when the tach jumps?
It doesn’t run funny, however, I don’t feel as much power as I should be. In first gear, I floored it and the tachometer would only jump up to about 5-6k rpms, no further. But at the same time, I can’t correctly tell where my rpms are when they start jumping since it goes up and down quickly. And I noticed another thing with the fuel consumption. The marker was above the 1/4 line, and I drove it for a couple miles, and it was already below the 1/4 by the time I got back. And when I turn the car on fully and give it some time, the fuel gauge will start to very slowly go back up. Not sure what’s wrong with the fuel system.

Here’s the gas gauge right after turning it on. You can see it slowly starts to go up. And it was initially right below that 1/4 line.
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Without even moving the car and just sitting here for a few minutes, it went down to this.

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I Would ignore all these smaller problems for now. Does it still overheat? Is it misfiring?
I have not seen the temperature gauge rise above half since I have changed the battery terminal and radiator cap. I even tried to do a couple pulls in 1st, 2nd, and 3rd gear and the temperature didn't increase past half. I also have no received a check engine light since I have changed those, and nothing has come up during the pulls. However, I cannot say for sure that it is not misfiring because of the jumpy rpms, and because I am not sure the car is getting as much power as it should be in gears 1-3. However, I have never driven this type of car before, so I can't compare it to anything.
 
You should replace your coolant cap, it looks stock and has to be bad by now, it may or may not be a problem with your overheating but I have had it be a problem on my car before, either way for good measure you should replace it anyway, if it hasn't failed yet it will at some point.
 
You should replace your coolant cap, it looks stock and has to be bad by now, it may or may not be a problem with your overheating but I have had it be a problem on my car before, either way for good measure you should replace it anyway, if it hasn't failed yet it will at some point.
Hi, if you're talking about the radiator cap, I just replaced that today. Is that what you were talking about? As of right now my main concern is the misfiring and the jumpy rpms since I can't risk knowing whether the vehicle overheats or not by accelerating or else the engine could get damaged.
 
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Hello, just to update: I turned my car on right now and the P0300 code turned right on as soon as I started it. Merely accelerating in first gear resulted in it misfiring and loss of acceleration. I am not quite sure what the issue is. I changed the spark plugs, radiator cap, battery terminal, coolant seems good, didn’t overheat, but also didn’t want to drive it because it started misfiring instantly. Need advice on what I should do or check. Thanks.
 
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