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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.
 
Have you picked up a handy Haynes manual for the car yet? If not that is the first thing that you need so that you can keep from spending money on mechanics to do the job. If you plan on keeping this car for a good amount of time you need to get familiar with every major part that is on this car and also know what usually goes wrong with these cars. Just make sure that any time you post issues we need to know what you were doing at the time of the issue and a picture of the issue if it is easily seen.

Here is a link to the manual that you should be able to get at any parts store or on Amazon etc.: https://www.autozone.com/ignition-t...haynes-vehicle-repair-manual-68031/392517_0_0
I have not picked up one of those manuals. I do plan on keeping the car for a very long time. It's difficult to work on cars without proper tools. I know auto part stores lend it, but the ones nearby are not so good because people tend to steal. There are certain things on the car that I just don't know how to do and I am not confident enough to do it because I don't want to risk messing it up further.

If the water pump needs replacing you might as well be doing a whole timing belt job. Sure, $300 isn’t bad until that doesn’t fix it and then you get another 3-500 quote for whatever he wants to guess next.
I see where you're coming from, but the pump has a leak, whether or not I do it now, I'm going to have to replace it at some point. It could be a reason for the overheating, but I won't know, and will have a peace of mind if it's fixed and working properly. And I don't know anything about a timing belt job. Can you give me information on what I should and need to know about it like what's a reasonable price, why it should be done, etc? When I turn on the car SOMETIMES, the car will make a loud squealing sound.

I am concerned because he told me that there might be a problem with the head gasket and I asked how he knew. He said that the tube connected to the radiator cap and to the radiator shouldn't have as much pressure as it did. When I gripped it, I could squeeze it just a bit but could feel the pressure against it inside. I don't know anything about that and would also like to be made aware if this is something that's true or if he is dishonest.
 
Overheating can be from a number of things. It could be the thermostat, faulty temperature sensor, radiator leaking, fan not running, water pump, or the worse case scenario the head gasket. Head gasket you you should at least see white smoke in the exhaust and gets worse with higher RPMs. As far as the squealing sound it could be one of the belts that are loose or bad but get us a video of the squealing sound when you crank the car.
 
I see where you're coming from, but the pump has a leak, whether or not I do it now, I'm going to have to replace it at some point. It could be a reason for the overheating, but I won't know, and will have a peace of mind if it's fixed and working properly. And I don't know anything about a timing belt job. Can you give me information on what I should and need to know about it like what's a reasonable price, why it should be done, etc? When I turn on the car SOMETIMES, the car will make a loud squealing sound.

I am concerned because he told me that there might be a problem with the head gasket and I asked how he knew. He said that the tube connected to the radiator cap and to the radiator shouldn't have as much pressure as it did. When I gripped it, I could squeeze it just a bit but could feel the pressure against it inside. I don't know anything about that and would also like to be made aware if this is something that's true or if he is dishonest.
That information can be found in the maintenance guide that I’ve already shared with you previously. Here it is again:


I realize you are new to the car and it has several things going on with it that you are worried about, but please try to take the advice given here. This includes reading up on 30 year old topics that are well documented. We can only help you if you let us.
 
If the water pump is coming out the timing belt has to come off. At least I dont know any other way of getting the pump out without removing the timing belt. Might as well just tell him to replace the timing belt while its off. And maybe replace the timing belt tensioner arm while you are at it, and possibly the pullies. While its in that state everyone here on the forums would probably just go that extra step and get it over with.

There are test kits that checks for exhaust gases in your coolant, but I really dont know how good or reliable they are. Ive seen people use it with success, and some who used it and it said nothing though there was an issue.

In terms of tools, it depends on how much you want to spend. I would at least take a look at them. The only thing I would suggest is to get a kit with 1/4, 3/8 and 1/2 drive ratchets and sockets to accompany them. It would start you out.


Something like that would get you started at least. But if there are torque specs, which most is with the engine and stuff, you would need to get torque wrenches.

To start out though look at those kits. They arent just good for cars. Ive used my kit on just about everything. Car, motorcycle, bed frames. They are just handy to have in general.

Ill let other people more experienced talk about the head gasket stuff. I havent personally ran into that issue yet with a blown head gasket.
 
I’ve used those color changing liquid tests before (and with success) but I think a coolant funnel and leak down tester gives more accurate results.
My dads van had an overheating issue with it and the pressure was going sky high. I think he used a pressure tester on it. I think with his van it wasnt the head gasket even though he changed both of them, but it was just plugged up so the water wouldnt circulate which caused it to boil and build pressure. I had unplugged several of the passages when the heads came off. Actually got what it was out and vacuumed it all up. Been running cool ever since.

Really who knows why the eclipse is building pressure. Could be a bad head gasket, could be someone put something in the coolant to stop a leak which ended up clogging a passage. That overheating could cause a head to warp so it needs to be addressed regardless of what it is.
 
Overheating can be from a number of things. It could be the thermostat, faulty temperature sensor, radiator leaking, fan not running, water pump, or the worse case scenario the head gasket. Head gasket you you should at least see white smoke in the exhaust and gets worse with higher RPMs. As far as the squealing sound it could be one of the belts that are loose or bad but get us a video of the squealing sound when you crank the car.
Yea it could be one of those things but I don't know how to check for it. I don't think its a head gasket because there's absolutely no white smoke coming from the car even while driving it hard. However, there are certain things that I may be able to rule out. If a thermostat isn't working, it's either stuck open or stuck closed. If it was stuck closed, it would overheat all the way to the top even when idling. If it's closed it wouldn't heat up at all. So I don't think it's that but my reasoning could be wrong. Here's a video of what it sounds like.
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That information can be found in the maintenance guide that I’ve already shared with you previously. Here it is again:


I realize you are new to the car and it has several things going on with it that you are worried about, but please try to take the advice given here. This includes reading up on 30 year old topics that are well documented. We can only help you if you let us.
Thanks man, I understand that, and I'll try my best, however, I'm not confident when it comes to reading a manual because I feel like I'm going to screw something up really badly, or misunderstand directions. I will give it a try, but the car is with a mechanic and I am an hour and a half away so there's not much I can do.
If the water pump is coming out the timing belt has to come off. At least I dont know any other way of getting the pump out without removing the timing belt. Might as well just tell him to replace the timing belt while its off. And maybe replace the timing belt tensioner arm while you are at it, and possibly the pullies. While its in that state everyone here on the forums would probably just go that extra step and get it over with.

There are test kits that checks for exhaust gases in your coolant, but I really dont know how good or reliable they are. Ive seen people use it with success, and some who used it and it said nothing though there was an issue.

In terms of tools, it depends on how much you want to spend. I would at least take a look at them. The only thing I would suggest is to get a kit with 1/4, 3/8 and 1/2 drive ratchets and sockets to accompany them. It would start you out.


Something like that would get you started at least. But if there are torque specs, which most is with the engine and stuff, you would need to get torque wrenches.

To start out though look at those kits. They arent just good for cars. Ive used my kit on just about everything. Car, motorcycle, bed frames. They are just handy to have in general.

Ill let other people more experienced talk about the head gasket stuff. I havent personally ran into that issue yet with a blown head gasket.
What are the test kits supposed to tell me if there is exhaust gases in my coolant? Does that mean there's a head gasket leak or something else? Yea if the guy is going to replace the water pump, I'm going to give him a new kit as well for the tensioner, pulleys, all the belts, etc. What are these kits called and could you direct me to a reliable kit for replacing this. And thanks for the tools, I'll look into it.

I’ve used those color changing liquid tests before (and with success) but I think a coolant funnel and leak down tester gives more accurate results.
I'll definitely look into that and see what I can do. Thanks homie.

My dads van had an overheating issue with it and the pressure was going sky high. I think he used a pressure tester on it. I think with his van it wasnt the head gasket even though he changed both of them, but it was just plugged up so the water wouldnt circulate which caused it to boil and build pressure. I had unplugged several of the passages when the heads came off. Actually got what it was out and vacuumed it all up. Been running cool ever since.

Really who knows why the eclipse is building pressure. Could be a bad head gasket, could be someone put something in the coolant to stop a leak which ended up clogging a passage. That overheating could cause a head to warp so it needs to be addressed regardless of what it is.
So where exactly was it plugged? In the water pump area? When I looked at the water pump, where the leak was, it was greenish and wet, and looked like someone didnt pour in distilled water and instead used tap water or something like that. It looked green and gross, almost like moss.
 
There are passages around the cylinders that water flows through. A few of these were plugged on his van so water couldnt circulate properly bad circulation led to water sitting in an area, boiling and causing the system to pressure. A bad head gasket can force pressure into the system as well. I mix tap water with my coolant and it doesnt have what sounds like a cloudy look to it. Its going to be a green color if you are using green antifreeze, but cloudy or looking like moss sounds like something foreign is being introduced into the coolant system.

It should look a greenish clear color.

I dont know which tests are reliable. But they have a liquid that changes colors when exhaust gases pass through it. I think the one I seen you actually put it where the radiator cap goes, and you test the system directly. You run the car, and then you use the pump on the kit which pulls gases from the system through the liquid. If it changes color you know exhaust gases are being introduced.
 
7131
That's why I order a box. Good luck spending less at auto oarts store.
Hey what did you mean by you "order a box?" How do you get them for cheaper?

Have you picked up a handy Haynes manual for the car yet? If not that is the first thing that you need so that you can keep from spending money on mechanics to do the job. If you plan on keeping this car for a good amount of time you need to get familiar with every major part that is on this car and also know what usually goes wrong with these cars. Just make sure that any time you post issues we need to know what you were doing at the time of the issue and a picture of the issue if it is easily seen.

Here is a link to the manual that you should be able to get at any parts store or on Amazon etc.: https://www.autozone.com/ignition-t...haynes-vehicle-repair-manual-68031/392517_0_0
Someone told me to not use the haynes
 
Haynes might work for you, I think it may be geared more toward beginners so you might understand things better. I would recommend comparing the instructions you find there to the ones in the FSM just to verify and let us know if you see any discrepancies we can help clear up.
 
Hey what did you mean by you "order a box?" How do you get them for cheaper?
rockauto.com
ngk 7131 are under 2$ a plug so I order in boxes of 10 just for convenience. No idea why they pack them in 10 but they do.
rockauto charges shipping. Over the years I've found it best to stock up on consumables all at once to save shipping. I'll buy windshield wiper blades, plugs, wires, filters, gaskets etc. When you find your car on rockauto check out the RSS parts also. Parts on sale are so cheap I'll buy a bunch just to have. 3 or 4 oil filters, Gasket sets so cheap I buy them just to have.
I have 7 cars I try and maintain
 
rockauto.com
ngk 7131 are under 2$ a plug so I order in boxes of 10 just for convenience. No idea why they pack them in 10 but they do.
rockauto charges shipping. Over the years I've found it best to stock up on consumables all at once to save shipping. I'll buy windshield wiper blades, plugs, wires, filters, gaskets etc. When you find your car on rockauto check out the RSS parts also. Parts on sale are so cheap I'll buy a bunch just to have. 3 or 4 oil filters, Gasket sets so cheap I buy them just to have.
I have 7 cars I try and maintain
Ahhh that makes so much more sense. I was thinking “by the box” you meant four spark plugs since there is four in a box. At the moment I’m trying to find products that have the same shipping truck icon so that shipping doesn’t kill me haha. And god damn, 7 cars is a lot.

Haynes might work for you, I think it may be geared more toward beginners so you might understand things better. I would recommend comparing the instructions you find there to the ones in the FSM just to verify and let us know if you see any discrepancies we can help clear up.
Ok yea I’ll go ahead and get the Haynes manual and try it out. Looking up how to do an egr valve, starter, and timing belt + water pump job soon, and could really use the simple steps. Thanks.

In terms of doing a full Timing Belt job, should I buy the timing belt kits that comes with a water pump or should I buy it all separately on rock auto or something?
 
Haynes might work for you, I think it may be geared more toward beginners so you might understand things better. I would recommend comparing the instructions you find there to the ones in the FSM just to verify and let us know if you see any discrepancies we can help clear up.
I have a Haynes book and to be honest, its pretty good. There arent some things in it and all the torque stuff in it that I checked in other places that use the FSM look to be the same. I will reference other stuff all the time though.
 
I'll put my opinion in. Gates can suck it. I will not buy any more of their timing components.
Opinion noted, thanks.

I have a Haynes book and to be honest, its pretty good. There arent some things in it and all the torque stuff in it that I checked in other places that use the FSM look to be the same. I will reference other stuff all the time though.
Okay awesome, I'll look into purchasing one very soon. Thank you for the clarification. Time to put the work in.
 
So here’s an update on what happened yesterday. I had to drive back to school in the eclipse. When I took it out on the road and freeway, I gave it just enough gas for it to accelerate very slightly, however, giving it anymore than that would result in the tachometer slowly start to jump, and with too much gas, the tachometer would jump and bounce really high and then misfire (I would know it would misfire because I cleared the check engine light and it would show up as well as a quick rumble). If I have it just enough gas, the rpms would travel smoothly up. It only misfired twice on a 2 hour drive back. And that was when I would give it a little more gas than usual.

In regards to the temperature, the car would start to overheat as I would enter an incline on the freeway so I would try to come up to a good enough speed (60-65 mph) and then cruise most of the way up the incline so the temperature gauge wouldn’t go up and it would work. I also turned on the heater and sent in all hot air into the interior of the car which I believe also helped enough to get me by.

At this point I have a very great feeling that it’s something fuel related, however, I cannot be too sure. This was a quick update I wanted to give and wanted to know if this is something someone has come across and knows what it is.
 
So, what did the mechanic end up doing with it? What all of the suggestions in this thread have been ruled out? Gotta start narrowing this down. Fuel issues don’t cause overheating but coolant leaking into the combustion chamber can cause misfires.
 
So, what did the mechanic end up doing with it? What all of the suggestions in this thread have been ruled out? Gotta start narrowing this down. Fuel issues don’t cause overheating but coolant leaking into the combustion chamber can cause misfires.
The mechanic ended up wasting 2 weeks of my time only to tell me there’s a water pump leak. He said he’s very busy so if I want my car back I can come pick it up.

The suggestions in this thread haven’t been ruled out, I just don’t have the equipment to check it.

I also never said fuel issues are causing the overheating. I think the fuel issues is what’s causing the misfires, but the overheating is most likely caused by a bad thermostat or the leaking water pump.

A friend of mine told me that his friend had a Miata with the exact same problems, misfires, jumpy tachometer, electrical glitches (this one is a bit new, last night while driving on the freeway, the speedometer dropped down to 0 while still going at a normal speed. The car didn’t slow down, but something in electrical caused it to go to 0 then back up to 60). He told me that this was all caused by a loose ignition switch. When they took off the panel behind the steering wheel. They taped the ignition switch with electrical tape, and it solved all of their problems.

Since I brought the car with me to school, I have no tools, no space, and essentially no time to work on it because of school. There is a professional mechanic shop nearby which I might end up taking it to, and just bite the bullet on the price if the ignition switch method doesn’t do the trick.
 
Yea it honestly sucked and the worst part was that I found out the passenger side window button and lock button was caved in, like it’s pushed down into the door. And that was not like that beforehand so he broke it. And nothing I can do about it because he’ll probably deny it. :/
 
I am not quite sure. I’ll look into it. Don’t they work on the car for free in order to teach the students? My roommate told me about something like that in regards to automotive schools, but not sure if mine has one. Thanks for pointing that out
 
Yeah. Worth looking into. I’m sure you’d have to supply the parts, and obviously the mechanics are beginners but at least they have one or two teachers that knows something and all the necessary equipment. You could make a list of the things that need checking from this thread and have them go thru that.

I did a couple semesters in auto tech before i just took advantage of their job placement program and didn’t go back. While I was there I replaced an engine in a trailblazer for one of the staff.
 
I’ve been here before and I’m here again.
1997 Mitsubishi Eclipse GST Spyder Manual
- Bone stock except for intercooler pipes and blow off valve.

Issue:
- P0300 Random Misfire (Only in gear under throttle, not when idling)
- Low voltage
- RPM gauge jumpy/bouncy under load only in gear.
- Fuel smell coming from engine bay.

Tests done:
- Compression test (180 across the board)
- Boost Leak test
- Smoke test
- Injector test
- Fuel Pressure test at return port (Will do another at the fuel pump)

Fixed/Replaced:
- Timing belt
- Valve cover + gasket

- Spark:
—> New plugs
—> New Wires
—> New Coil packs

- Air:
—> Boost leak tested 3 times
—> Smoke tested
—> Replaced Intercooler pipes because of vacuum leak
—> No other visible leak
—> New cx racing (Greddy replica) blow off valve

- Fuel:
—> Fuel pressure tested the fuel pump
—> New fuel filter
—> Tested and got new seals and pig tails for injectors

- Electrical:
—> New battery
—> Replaced alternator twice with 90 amp galant alternator. Brand is Ultima.
—> Redoing the grounds right now because car has low voltage.
—> New terminals


I don’t know what’s causing this random misfire. When it’s in gear and it misfires, I have to put the car in neutral and back into gear in order to stop the misfires and this works most of the time. I’ve also attached a screenshot of my monitors on my phone when the OBD is connected.

I need help and before anyone says to look at old posts, I have looked at quite a few, but nothing is close to what I have. If anyone has advice or can link an old post that has symptoms similar to mine, I will gladly take the help.

Thanks,
Z.

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