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Check engine light on and RPMs keep jumping

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95eclispe

10+ Year Contributor
261
5
Dec 31, 2011
Brooklyn, New_York
Ok so my check engine light is on but i never bothered to get it checked. recently when the light goes off when i rev or raise my RPMs it stutdders all over the place and when it goes down below 1000 my car loses power and shuts off. I have to start my car in first gear and take off at high rpms to keep it from shutting off. Earlier today i started it and my check engine light was back on but the car was running normal. Any idea what this could be?
 
I would personally start with plugging in an OBD scanner and figuring out what the check engine light is on for. Be a good starting point!
 
Well if it goes haywire when the CEL comes on, then more than likely it's directly related to that code. I would check it out.

Other than that, my old 95 n/t act nutty as shit like you're talking about when the rear o2 sensor had the wiring to it ripped out by something snagging on it.
 
Ok so my check engine light is on but i never bothered to get it checked. recently when the light goes off when i rev or raise my RPMs it stutdders all over the place and when it goes down below 1000 my car loses power and shuts off. I have to start my car in first gear and take off at high rpms to keep it from shutting off. Earlier today i started it and my check engine light was back on but the car was running normal. Any idea what this could be?

Usually in my experience when the rpm gauge go on the, fritz like that its the crank sensor. On your 420a you need to change your crank & cam sensor. This will solve your problem. Use OEM only from the dealer.

Had a pt cruiser with a problem go through 4 different part store cam sensors and when a oem dealer sensor was used it solved the problem.
 
Usually in my experience when the rpm gauge go on the, fritz like that its the crank sensor. On your 420a you need to change your crank & cam sensor. This will solve your problem. Use OEM only from the dealer.

Had a pt cruiser with a problem go through 4 different part store cam sensors and when a oem dealer sensor was used it solved the problem.

I just had cam and crank sensors done a month ago when my timing went. so i dont think thats what the problem is but ill trou8ble shoot it just to rule it out

Well if it goes haywire when the CEL comes on, then more than likely it's directly related to that code. I would check it out.

Other than that, my old 95 n/t act nutty as shit like you're talking about when the rear o2 sensor had the wiring to it ripped out by something snagging on it.

and it doesnt go haywire when the CEL is on it does the complete opposite is why im baffled. When the CEL is on is when its fine...the moment it goes off is when it starts acting up you would think its the other way around:hmm:
 
Why did you have the cam and crank sensors changed a month ago? And did you get the parts from the dodge/chrysler dealer or parts store?

And no not really with the CEL. When it goes off ecu is not sensing/compensating for the problem. Had this happen with a lincoln b4. Car misfire real bad under a load. Once the ecm notice enough off it it would flip the CEL and switch to a limp mode where it would run fine. You need to look up that code if pssible.
 
First off guys, unless he can track down something to scan OBDI, he won't be pulling any codes he's got a 95. He needs to do the key dance. BlueNinja is on the right path. It sounds like whatever the problem is, when the CEL kicks on, it's going into limp mode, so definitely look into your sensors.
 
First off guys, unless he can track down something to scan OBDI, he won't be pulling any codes he's got a 95. He needs to do the key dance. BlueNinja is on the right path. It sounds like whatever the problem is, when the CEL kicks on, it's going into limp mode, so definitely look into your sensors.

My 95 is ODB2, I'm pretty sure all 2gs are ODB2.
Mine even has a 94 build date.
 
Sure isn't. It's got an OBDII port, but OBD2 were not put into effect untill 96. Hook up a scan tool and get back to me when it won't light up...


Here is a picture of my ODB2 scan tool hooked up to my 1995 2g (with a 1994 build date).
I just ran outside and took this picture.
 

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Sure isn't. It's got an OBDII port, but OBD2 were not put into effect untill 96. Hook up a scan tool and get back to me when it won't light up...

Obd2 was required in all vehicles produced in 1996 and up. Mitsubishi and some other manufactures switched over early. If it has an obd2 port it is obd2. To the op: go get your car scanned.
 
Here is a picture of my ODB2 scan tool hooked up to my 1995 2g (with a 1994 build date).
I just ran outside and took this picture.

thats cool, this is my OBD2 scanner, with wifi capabilities.

but on a serious note the computer giving you the code and you reading it IS the very first step, not ignoring it, why did you wait until the problem became mechanical... sheesh. some vehicles cut-off's/shuts down the sensor or the system once identified it has malfunctioned to prevent further failure. that's why it may not give you problems when the light is on. the ECU is a reactive system and not a proactive one. It will react/adjust to anything that GOES bad, not prevent it or foresee any possible problem.
 

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the technical name for 95-96 obd2 plug equiped vehicles is obd1.5.. some scanners work like normal and others you have to use the "universal/global" setting when you hook it up.
 
the technical name for 95-96 obd2 plug equiped vehicles is obd1.5.. some scanners work like normal and others you have to use the "universal/global" setting when you hook it up.

That's what I thought. I had a 95 that would not scan, checked all the pins and the plug worked fine. Hooked up a universal and whammo! :idontknow:
 
Anyone know of any places that scans codes for free? i remember autozone used to do it idk if they still do. really stretched for cash right now til next week or else i would just by one. Once i get it scanned and it throws a code(if any) ill get back to you guys

Why did you have the cam and crank sensors changed a month ago? And did you get the parts from the dodge/chrysler dealer or parts store?

And no not really with the CEL. When it goes off ecu is not sensing/compensating for the problem. Had this happen with a lincoln b4. Car misfire real bad under a load. Once the ecm notice enough off it it would flip the CEL and switch to a limp mode where it would run fine. You need to look up that code if pssible.

I had them changed out through mitsubishi dealership when my car jumped timing. I had the sensors tensioner and timing belt replaced. When i got the car there was no records of what work/parts have been replaced on it so i figured i start from scratch replacing all the vitals on the car first before i do any real mods
 
Anyone know of any places that scans codes for free? i remember autozone used to do it idk if they still do. really stretched for cash right now til next week or else i would just by one. Once i get it scanned and it throws a code(if any) ill get back to you guys



I had them changed out through mitsubishi dealership when my car jumped timing. I had the sensors tensioner and timing belt replaced. When i got the car there was no records of what work/parts have been replaced on it so i figured i start from scratch replacing all the vitals on the car first before i do any real mods

It jumped time? Did you double check that there wasn't any damage to the valves before putting it back together?

On a side note; yes 1996 was the mandate for OBD2. However, some cars that were in the middle of a body redesign, got the early version of OBD2 in the model years before 1996. If I recall, it was "voluntary". I've seen that the early 4th gen f-bodies also were OBD2 compliant. Yet, my '95 Mustang is not. Figures. ;) Then again, Ford still used the 302 until 1996, when the new "modular" engine was introduced into the Mustang, so maybe that's what they were waiting for...
 
It jumped time? Did you double check that there wasn't any damage to the valves before putting it back together?

On a side note; yes 1996 was the mandate for OBD2. However, some cars that were in the middle of a body redesign, got the early version of OBD2 in the model years before 1996. If I recall, it was "voluntary". I've seen that the early 4th gen f-bodies also were OBD2 compliant. Yet, my '95 Mustang is not. Figures. ;) Then again, Ford still used the 302 until 1996, when the new "modular" engine was introduced into the Mustang, so maybe that's what they were waiting for...

i checked for any bent or damaged valves but they were fine. I even bought a new head thinking right off they were damaged but turned out fine so now i have an extra head

ok so just an update: i went and tried to get the codes read. the first time my check engine light wouldnt come on. after driving it around for a bit it came on so i hooked up the OBD2. it gave me two codes: one for the EGR valve control unit and the other for the O2 sensor in bay 1. Any light on this?
 
i would pull that O2 sensor out and if it is burned up replace it. up-stream o2 sensors affect air fuel ratio. also go back to autozone and have them pull up freeze data just to see if any other codes have ever caused the light to come on.

also the egr valve and solenoid are sold as an assembly, try a salvage yard or junkyard the solenoid comes off very easy and will save you lots of money this way.
 
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