1G 93 GS running poorly when warm, bogging, revs climb slow

[420sx]

Im trying to fix my sisters old 1993 eclipse GS (auto) for my girl to drive. The car starts and runs, but once it warms up, it runs so poorly that it cant even be moved. When its cold it has good throttle response and revs up smoothly. Once its warm, it has terrible response in park or neutral, and the rpm's climb very slowly. The way it bogs reminds me of the way a 2 stroke engine bogs when it has a dirty carb. When the car is put into gear, the engine stays running, but barely. It wont rev up enough to move the car, it will just sit at around 1200rpm and stutter. Anyone have any ideas?

Its throwing a CEL.. how do I go about pulling codes on this car? Im not a DSM guy.. i know the ECU is in the center behind the dash. Does this car utilize a "diagnose" mode, in which i count the blinks on the dash, or does it have a light on the ecu itself that displays the codes? I checked the spark plugs, theyre nice and tan, still giving a fat blue spark. I thought the problem might be the thermostat, and suspecting it was stuck closed, I removed it. If this was the problem, removing it should have solved it. I'll put another one in once I have the car running right, but at least i know that's not the issue.


Any insight would be greatly appreciated.

 

[falcon8r]

The ect sender is right there at the thermostat housing. That will make the car undrivable for sure. Yes the codes come out sim. to ford eeciv where you can count sweeps of an analog volt or watch the light blink. Same kind of blink -off -blink -blink -stuff. It's all right here in the forum. Look in the VFQ and fix that thing. Tres...

 

[90laser0087]

i've had similar symptoms when when my ecu was on its way out, i've seen this a few times, you can check the codes if you you hook an analog voltmeter between terminal 12 and 1 on the data link connector on left side under the dash. then count the number of voltage sweeps on the needle

 

[420sx]

I picked up a thermostat and an ect sensor yesterday and will be installing them today. They were cheap, and are easy to install, so i figured id just pick em up. If that doesnt solve my problem, im gonna have to pull the codes. I assume there is a write up on this, which ill have to search for. If anyone else has and other ideas or input, any information specific to this car or problem is greatly, greatly appreciated.

 

[brownfinger]

Is the engine bay reasonable looking, or is there a bunch of disconnected things and electrical splices and missing pieces? It could be a plugged fuel filter, a bad section of wire where the terminal fits on the sensor, etc... Coolant sensor wires are notorious for this. For god's sake, pull that code before you spend any more money. If you use a light to pull the code, use an led, not an incandescent.

 

[420sx]

The engine bay is reasonable. Ive worked on this car myself for a number of years, but in the past the problem has been (more than once) the transmission. Ive replaced it twice, and the torque converter once. I know my way around the engine bay, but my knowledge of this specific car is limited. I replaced the ECT sensor and the thermostat last night. My symptoms are now similar, but with a confusing twist.

About two weeks ago I tried to jump start the car since it had been sitting for a few months (since it started running like dog crap). I jumped it, expecting it to start, run, and idle (albeit like shit). Well it started, ran, and idled, but when I disconnected the lead from my car that i was jumping it with, the eclipse would die. This would be indiciative of a bad alternator, no? So I ordered an alternator. Long story short, i never ended up getting it. Ended up tightening the leads on the battery, jumped it, and it would stay running... so at this point I'm thinking the alternator is fine.

Last night I changed the ECT sensor and the thermostat, and now the car wont stay running without being connected to my 240sx's battery. When it is running, it runs sloppily and wont rev past 3000. The revs climb very slow still, and when put in the gear the car cant move itself. Its doing this even when the car is cold. It starts up fairly reliably, but it just wont run right. Im going to pull the codes today.. can I use a regular car speaker to hear the pulses? And i hook the speaker up to the MPI terminal and the ground terminal on the diagnostic port?

 

[Morphius]

Best advice I can give you to start is go buy a Hayes manual at the local Autozone. There is a lot of good info in there. (Factory manual is even better, but expensive.) Likely the best $16 you'll ever spend for your car. Read it, reread it. It will detail on how to pull codes, check sensors, etc.

Pulling codes should be your first step. You'll need a analog voltmeter or have the autozone worker pull them.

Based on codes we could give you better advise on what to look for, check or try. Otherwise, we can give you 1000 different things that might be wrong.

 

[brownfinger]

Best advice I can give you to start is go buy a Hayes manual at the local Autozone. There is a lot of good info in there. (Factory manual is even better, but expensive.) Likely the best $16 you'll ever spend for your car. Read it, reread it. It will detail on how to pull codes, check sensors, etc.

Pulling codes should be your first step. You'll need a analog voltmeter or have the autozone worker pull them.

Hey old man, they're $26 these days! But it's still worth it. To pull the codes, use an analog VOM (and count sweeps of the needle), or an LED (an incandescent pulls to much current, can damage ecu). Autozone can't pull codes for a 1G/OBD 1.

http://www.vfaq.com/mods/wayback/BradBauer/electrical/code.html

 

[90laser0087]

try pulling the cover off the pcm and see if the capacitors are leaking into the board, or see if it looks melted?

 

[420sx]

The code its throwing is a code #44... ignition, power transistor module...? I picked up a PTM locally for $15... how the heck do I install it? It looks like its held on by two phillips head screws, but there is no freaking way I'm getting a screwdriver down in there. Whats the protocol on changing this part? What else do I need to take off to get in there?

If this doesnt fix my problem, I'm going to test the coil, and then the ECU. The ecu was replaced with a new/reman ecu about a year ago due to leaky capacitors, so I'm kind of doubting that thats the problem. Im really praying that this PTM is my issue.

Also the other day when I started the car, it was running poorly like usual so I left it to idle while I was messing around with it. It was idling at like 450rpm. I decided to pull the plug wires one at a time to see if there was any difference between them. There wasnt. The thing that perplexed me was that after i pulled them off and put them back on one at a time (without stalling the engine), the engine started to run FINE after i had them all back in. I took the car down the road, and the engine seemed to be running normal. The transmission was shifting rough, but this car has always had tranny issues, so that didnt suprise me. Im wondering if the car ran right because of me f*ckin with the plug wires, or if it was because i left it idling, and whatever problem I'm having is happening only when the car is cold. So far the only stuff Ive done relating to the ignition was plugs and wires. Prior to that, this car was 100% undriveable.

Im going to change the PTM and see if that fixes it.. just need some help on the install! Thanks a ton guys!

Oh, and when I was pulling the plug wires- all four of them were sparking. Not sure if they were sparking on initial start up though. When the car is running poorly (throwing the code), the RPM's seem to read half. It wont go above 3000rpm on the tach, but the motor gets loud as hell, so I cant imagine that its only at 3k. A lot of people experience tachometer issues pertaining to the PTM, but a lot of people also say they run on 2 cylinders with a bad PTM. I'm running on 4 cylinders as far as I know. Is it possible for the PTM to be bad when its cold, and then once the engine warms up, it starts working? When it started working, the CEL went away completely. It ran 100% normal (well.. normal for what it is.. its never really run NORMAL, ). Yes, I realized my symptoms have completely 180'd... I'm just as confused as any of you. When i started on the car it would rev normally when cold and the symptoms were present when it was warm. Now its the opposite.

 

[Morphius]

The code its throwing is a code #44... ignition, power transistor module...? I picked up a PTM locally for $15... how the heck do I install it? It looks like its held on by two phillips head screws, but there is no freaking way I'm getting a screwdriver down in there. Whats the protocol on changing this part? What else do I need to take off to get in there?

If this doesnt fix my problem, I'm going to test the coil, and then the ECU. The ecu was replaced with a new/reman ecu about a year ago due to leaky capacitors, so I'm kind of doubting that thats the problem. Im really praying that this PTM is my issue.

Also the other day when I started the car, it was running poorly like usual so I left it to idle while I was messing around with it. It was idling at like 450rpm. I decided to pull the plug wires one at a time to see if there was any difference between them. There wasnt. The thing that perplexed me was that after i pulled them off and put them back on one at a time (without stalling the engine), the engine started to run FINE after i had them all back in. I took the car down the road, and the engine seemed to be running normal. The transmission was shifting rough, but this car has always had tranny issues, so that didnt suprise me. Im wondering if the car ran right because of me f*ckin with the plug wires, or if it was because i left it idling, and whatever problem I'm having is happening only when the car is cold. So far the only stuff Ive done relating to the ignition was plugs and wires. Prior to that, this car was 100% undriveable.

Im going to change the PTM and see if that fixes it.. just need some help on the install! Thanks a ton guys!

Oh, and when I was pulling the plug wires- all four of them were sparking. Not sure if they were sparking on initial start up though. When the car is running poorly (throwing the code), the RPM's seem to read half. It wont go above 3000rpm on the tach, but the motor gets loud as hell, so I cant imagine that its only at 3k. A lot of people experience tachometer issues pertaining to the PTM, but a lot of people also say they run on 2 cylinders with a bad PTM. I'm running on 4 cylinders as far as I know. Is it possible for the PTM to be bad when its cold, and then once the engine warms up, it starts working? When it started working, the CEL went away completely. It ran 100% normal (well.. normal for what it is.. its never really run NORMAL, ). Yes, I realized my symptoms have completely 180'd... I'm just as confused as any of you. When i started on the car it would rev normally when cold and the symptoms were present when it was warm. Now its the opposite.

The PTM is attached to a bracket which is bolted on. You can get a socket/wrench in there. I'd first just plug the new PTM in without removing the old one.

Your issue kind of sounds like an issue I had with my car when the fuel pump was going bad. It was weak (low pressure) until it ran a while and warmed up.

 

[quiksilver20004]

This sounds like a fuel issue to me. Have you ever replaced your fuel filter?? Also a half tach signal would be cause by the CAS. It is the only device on the motor that accounts for timing and revs.

 

[420sx]

Fixed the problem. It was the Power Transistor Unit. Plugged the new one in, it hessitated for the first 20 seconds, then cleared up and has been running fine since. Thanks a lot guys! I was about to give up on this thing!

 

[quiksilver20004]

Its a DSM, you have to love the problems!