1G 1991 Plymouth Laser RS 2.0 Non Turbo misfire help

[Sambob]

I have a 1991 Plymouth Laser RS 2.0 Non Turbo that runs fine even after the engine is hot BUT if I turn in off and restart it while its still hot there is a very bad misfire and the check engine light will come on. Unfortunately no one has a scanner that will work for the car anymore. Any idea what would cause this?

 

[steve]

Easy to pull the codes with a multimeter, 12v piezo buzzer, or 12v LED. With a little more effort you can build a functional datalogging cable. Hardest part now is getting a copy of old software.

ECU Code Checking

1G - 1g Code Reader - CEL CODE READER

This is a How-To on figuring out your Check engine light (CEL) for 1g.Tools: Volt Meter or LEDConnection: Connect the positive of the volt meter or LED to pin #1 and the ground to #12 pin on the port. You must be registered to see element.After you got that done, turn your key to the ON...

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1G - The Easy Way to Make a 1G USB Datalogging Cable

Making your own USB data logging cable is just as easy, if not easier than making the standard serial cable. It is also more cost effective since the DB-9 serial version would require a USB to RS232 adapter, unless you have a laptop with a serial port. I selected this particular cable because it...

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1G - How to set up MMCD & make a logging cable

***This article is for OBDI DSM's***First thing you should do is get MMCD on your Palm, make sure you are using one of the supported devices from You must be registered to see element. Once you get MMCD on your Palm it's time to make the cable. I used 18 awg wire.Schematic: You must be...

www.dsmtuners.com

Getting the fault codes should point in the right direction, right now all people can do is guess.

 

[pauleyman]

Analog voltage meter will read codes also. 10$ or less

 

[Sambob]

I have a 1991 Plymouth Laser 2.0 Non Turbo that runs fine most of the time, however if I drive 30 minutes then turn the engine off for a few minutes it has a horrible misfire when I start it again. This misfire will usually go away after 5-10 minutes of driving highway speed, the check engine light does turn on while its misfiring but doesn't throw any codes. I've changed the coil packs, plugs and wires and it still does this, I saw a post similar to this saying they changed the fuel pump and it fixed it. Has anyone else experienced this issue? I'm thinking about changing the fuel filter if that doesn't help I will do the fuel pump and see how that goes unless someone here has the remedy.

 

[steve]

This misfire will usually go away after 5-10 minutes of driving highway speed, the check engine light does turn on while its misfiring but doesn't throw any codes.

Before replacing anything else, check the ECU and make sure the capacitors have been changed and that there isn't any corrosion damage. This is a generic problem for all 1G ECU due to bad capacitors in this era.

 

[pauleyman]

I have a 1991 Plymouth Laser 2.0 Non Turbo that runs fine most of the time, however if I drive 30 minutes then turn the engine off for a few minutes it has a horrible misfire when I start it again. This misfire will usually go away after 5-10 minutes of driving highway speed, the check engine light does turn on while its misfiring but doesn't throw any codes. I've changed the coil packs, plugs and wires and it still does this, I saw a post similar to this saying they changed the fuel pump and it fixed it. Has anyone else experienced this issue? I'm thinking about changing the fuel filter if that doesn't help I will do the fuel pump and see how that goes unless someone here has the remedy.

Throwing parts at the car is an expensive way to fix it. Gather data. Alot of it is cheap or free. Multimeter is helpful and many diagnostic pieces can be rented for " free". Refundable deposit. Steves comment is spot on. It's a known problem especially on a dsm this old. Basic visual inspection is free.

 

[Sambob]

Before replacing anything else, check the ECU and make sure the capacitors have been changed and that there isn't any corrosion damage. This is a generic problem for all 1G ECU due to bad capacitors in this era.

Where is the ECU located on this car? I will look into it, I think my dad may have changed it before Ill find out I know he had a few extra sitting in his shop.

 

[DSMPT]

Where is the ECU located on this car?

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