1G My GS only runs like it should for 15-20 seconds?

[mik3ripp3r]

okay...heres the deal....I bought a 94 eclipse gs 1.8 with about 5000 miles on a completely rebuilt motor but never got finished.... It ran perfectly after I replaced the fuel pump/ fuel pump relay, timing belt, distributor and an engine mount (basically finished it up after the rebuild).

Then.....about a year ago my idiot friend needed a jump start and in doing so he put the ground to the positive and the positive to the ground on my car! It sparked and lurched but still ran and didnt notice anything wrong...... until I went to drive it.

Whats happening is it only runs like it should after sitting overnight or is completely cold.... for about 15-20 seconds it runs like it just rolled off the showroom ..... then it goes into stumble mode like its only runnin on 3 cylinders or somethin for the rest of the day.... its really bad (especially on cold days) until it warms up, then its just kind of bad .... but still dosent run like it did after a cold start. It dosent top out rpms like it did and im sure im wasting fuel because of this and it is embarrassing.

I dont have a check engine light on and I know that works because I left my MAF unhooked and it triggered that. I tried replacing the coolant temperature sensor thinkin that had somethin to do with it but it didnt and I have read my haynes manual through about 100 times trying to figure this out.

I hope someone has an idea about what might be going on here and can help out because Im getting desperate here. Thanks.

 

[Mischif]

Are you sure you replaced the Coolant temp sensor(2 prong) and not the temp gauge sender(1 prong)?

For the first few seconds of a cold start the car runs off fuel maps in open loop, after that it goes into closed loop and uses the o2 sensor to dictate fuel. The 1.8 stays in closed loop most of the time, only time it goes into open loop is above 4krpm. So a malfunctioning o2 depending on what its doing could have it stumbling like yours is. It wont always throw a cel either. So i would look into testing that. If that turns out to be good then i would suspect the ecu.

 

[mik3ripp3r]

honestly, I got the temp sensor (2 prong) from the junk yard so that still might be the issue....I'll try again.... and the o2 sensor was right at the top of my list of things to try so I'll do that too. I do have a spare ecu from a california model though and when I hooked it up I got absolutely nothin.... no start at all. so Im guessing even though it is out of the same year it's probably not gonna work or I just got a piece of junk ecu? Thanks for the input! I NEED to figure this out!

 

[kleenf4i]

start simple. fuses and relays. Then you have to look for odd behavior. Your car will tell you whats wrong with it if you dial in on what the cause is. Is the a check engine light on? if so what are the codes? start here. Your ecu is fine otherwise it wouldnt start at all.

sensors are very sensitive. the maf sensor is the most over looked sensor. To check if the maf sensor is bad, un-clip the connector-was there a major change in idle or did it die? or now can you drive your car? a bad maf will always let you drive rich after un-plugging the sensor. There are other sensors that will do this also. We need to narrow it down. start with fuses and codes, if any, then go from there because you will defiantly throw codes by un hooking sensors

 

[mik3ripp3r]

thanks kleenf4i.... but as I said....no check engine light and and I had already left the maf sensor unhooked to check it and it still let me drive...even worse than before though....all my fuses are good.. so Imuna try the o2 and another coolant temp sensor and go from there..... It's reasuring what you said about my ecu but Ive heard that their are circuts and wires that can become damaged inside and still lets your car run....and there is a check engine light for that too....which again...I have none...

 

[kleenf4i]

NO PROBLEM, IT HAS TO BE SOMETHING SIMPLE, IN THIS CASE. Possible plug fouling? possible coil ? check spark on all cylinders in this case.Also if you didnt throw a code (WHICH YOURS DOES) by unplugging your MAF sensor plug, Points to a bad ECU. so rule out the ECU.

 

[iaintmaci]

I would at least pull your ecu and take a look at it. For all the longer it takes, it is worth looking at. An ECU is capable of having a capacitor going bad and still let the car run. It may have a circuit shorting out, and after that amount of time is causing the circuit to overheat. After it sits for a while, it could be cooling, and then the whole sequence starts over. It is not difficult at all to pull the ECU, and may give you a better idea.

 

[Spyderman7]

If your friend hooked up the jumper cables backwards then more than likely he fried your ECU.Pull the ECU out and open it up and check it out.

The car can run with a bad ecu but badly

 

[Diamond Star Werks]

It sounds like a bad coil. Pos to neg will kill a coil. Start your car let it idle when it starts running bad start pulling your plug wires off to see which cylinder is not firing. When you pull the wire off one and it doesn't change the way its running then change your coils around.

Not your plug wires or firing order just unbolt your coils and swap positions. This way the one controlling the affected cylinder controls the unaffected ones. If problem changes to a different cylinder then you have a bad coil. If it stays in that one cylinder then swap the injector from that cylinder to a different position and see if the issue follows the injector.

If it still stays in in one cylinder or if it is sparatic btwn cylinders you should test your CAS on the back of the head. It may have been damaged.

IMO I would think the ignition fuse would blow before such damaged it but it wouldn't hurt to check it. But I'd start testing things as I've said to narrow it down.

 

[kleenf4i]

+ 1 ^^^ Do this FIRST. Remember the ECU is fused. It will 99.999% of the time blow a fuse. The only time I have seen an ECU not blow a fuse and quit working is when people hooked up safc's wrong or the capacitors in the board blew up. You can always look at the ecu board, and check for anything burnt or blown up. I had this happen on my chrome pro computer for my prelude and i paid an electronics store to swap over all of the internals to a different board for 60$

 

[mik3ripp3r]

alright...I havent done anything yet but I'm starting to feel like an idiot ...and I view myself as fairly knowlegeable with mechanics.

first off....(from top to bottom) @kleenf4i The plugs have been replaced since this all happened and the if I am correct the coil(s) are internally within the distributor... and before this all happened I payed a pretty penny for a brand spankin new one with a lifetime warranty...so my question to you is... is their any way to take that out and just have it tested you think....or do I need to use my ohm meter and go back and demand a new one if I find variances?

Next @iaintmaci I understand what your sayin about a resistor being bad so I will try that....pullin my ecu is not anything I havent done before so thats not an issue.... opening one up though is new to me. Look for burnt wires and connections....got it! I was wondering though if you had any knowledge on a CA ecu Vs a federal one? I have a CA one also and my car didnt start at all after I hooked that up... do you know if they are compatible in any way or can I make it so?

and @Spyderman7 .... will check!

and lastly @MJcanada I dont quite understand about switchin my coils around? .....as far as I know it is either one coil and not seperate coil packs and/or they/it are/is internal and non serviceable within the distributor. so I don't quite understand how I would switch them around to test them/it.

I was reading also today and the purge control selenoid valve is also a know cause of poor perfomance.... any input on that anyone.

btw....I get paid in a few days and Ill be going through these from top to bottom and keep everyone updated....and again...thanks.

 

[iaintmaci]

CA and federal ECUs are compatible. Here is a link to tell you exactly what ECU you have. I believe if there is a resistor in R129, then it is federal. If not then it is a CA. Adding the resistor in will eliminate it from being CA.

Eclipse Talon Laser Galant 3000GT Stealth ECU ID Reference

With a CA ECU, it looks for the emissions. It may throw a check engine light if the EGR valve has been eliminated.

 

[mik3ripp3r]

thanks!

okay.. I pulled out my "CA" ECU and it is labeled 6/90-5/94 - MD159561
E2T33674A which shows being a federal unit. so Im thinkin the "ebay seller" didnt know what he had apparantly?" bottom line is though....my car did not start at all after I hooked this up....do I need to reset it in anyway?.... other wise im crackin this bad boy open and start familiarizing myself before I dig mine out from behind my dash...

he wrote on the unit also MSRP 1484.32 ... as in "manufacture suggested retail price".... ! I paid $600 less for the car itself!

opened the CA ecu and dont see anything melted or really abnormal.....the only thing I notice kind of odd it some gouey black residue around the connections of R122 & C4 circuts.... the other side looks fine around that area and nothing is melted at all.... I know Im gettin a little geekey with this and I dont expect anyone to really have any info on the internal schematics of an ECU... but you never know.

 

[kleenf4i]

alright...I havent done anything yet but I'm starting to feel like an idiot ...and I view myself as fairly knowlegeable with mechanics.

first off....(from top to bottom) @kleenf4i The plugs have been replaced since this all happened and the if I am correct the coil(s) are internally within the distributor... and before this all happened I payed a pretty penny for a brand spankin new one with a lifetime warranty...so my question to you is... is their any way to take that out and just have it tested you think....or do I need to use my ohm meter and go back and demand a new one if I find variances?.

yes you can test the coil indivisdually,ill have to get right back to you on the testing. You are correct, it will be through an ohm meter reading.

As far as your ecu is concerned, the "black goo" doesnt sound good but a description isnt a picture, it may be fine. Although Ive never seen any black goo in any ecu. could you snap a pic and post it? Please post pic of the entire ecu board. Thanks

here ya go:

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Measurement of the primary coil resistance.
Measure the resistance between connector terminals 3 and 2 (the coils at the No.1 and No.4 cylinder sides) of the ignition coil, and between terminals 3 and 1 (the coils at the No. 2 and No. 3 cylinder sides).
Standard value: 0.70 - 0.86 Ohms

Ignition Coil








Measurement of secondary coil resistance.
Measure the resistance between the high-Voltage terminals for the No. 1 and No. 4 cylinders, and between the high-Voltage terminals for the No. 2 and No. 3 cylinders.
Standard value: 11.3 - 15.3 K Ohms



CAUTION: Be sure, when measuring the resistance of the secondary coil, to disconnect the connector of the ignition coil.

WHAT THE HELL!!!! this is so annoying not being able to post pics.ugggggghhhhhhh! please pm me ill send this write up with pics to your e mail. stupid admin on this site!

 

[iaintmaci]

Here is a link to ECMlinks page on ECU damage. Black goo is not good. It sounds like something is blown. Take a look and see if anything looks familiar. Also post up some pics if you can. A picture is worth 1000 words.ecurepairhome [ECMTuning - wiki]

 

[kleenf4i]

+1 a pic would tell the whole story. ^ good link.

 

[mik3ripp3r]

this is all good ish! thanks ppl! Ill post up pics tomorrow of the spare ecu I have with a lil goo on it....but it looks nothing like those examples.....and...again....do I need to reset an ecu at all after a swap? because I didnt try that....I just slapped it in and no start so I took it back out....

 

[kleenf4i]

are you sure its the correct ecu?

 

[mik3ripp3r]

no but the numbers on the ecu link matched my year and if I understand correctly it is in fact not a CA unit. so....Ill pull my head unit tomorrow and get the numbers off the one I have that does "work" and we shall soon find out.

 

[kleenf4i]

also heres a service bullitin for your car. apparent its a well known issue. This means if A. you needed a jump you lost power, B. the mixing of terminals would temporially cause the ecm to lose power.... its a possibility.

NO.: TSB-93-13-004

DATE: August, 1993

MODEL: All 1989 - 1994 with ISC

SUBJECT:
ADAPTIVE MEMORY

PURPOSE

1989 - 1994 four cylinder engines equipped with an Idle Speed Control (ISC) system (the type which opens the throttle valve) have adaptive memory built into the Electronic Control Module (ECM). This memory accumulates information on how an individual vehicle operates and adjusts the vehicle's ECM programming for optimum driveablity. Adaptive memory resides in the ECM's Random Access Memory (RAM) and the information contained will be lost when power is not available to the ECM.

This bulletin explains:

1. If adaptive memory is lost, in some cases, the vehicle may idle roughly (too slow) or may not idle at all due to deposits on the throttle valve.

2. Use the Scan Tool (MUT/MUT II) to erase Diagnostic Trouble Codes. Do not disconnect the vehicle's battery.

3. Idle the vehicle for at least 10 minutes after the battery has been disconnected for any reason.

4. Do not assume that the ISC is inoperative if the vehicle won't idle or idles rough after the battery is disconnected.

5. If the vehicle will not idle after a battery is disconnected, clean the throttle plates as described in the appropriate vehicle's service manual.


ADAPTIVE MEMORY DETAILS

The Electronic Control Module (ECM) contains adaptive memory which remembers the vehicle's typical operating characteristics. One of the memory's functions is to remember the "normal" operating position of the ISC.

As a vehicle is operated, deposits build up inside the throttle body housing and on the throttle plates causing airflow to become slightly restricted. In these cases the ECM instructs the ISC to increase the opening of the throttle plate. The ECM learns that the vehicle requires a larger throttle opening to idle properly in its adaptive memory.

When battery voltage is removed from the ECM (i.e. battery is disconnected) this adaptive memory is lost. The ECM then does not know the vehicle needs a larger throttle opening to idle properly and responds with its basic factory (new vehicle) programming. Consequentially, the idle may become rough until the ECM re-adapts. Clearing the Diagnostic Trouble Codes with a Scan Tool does not affect adaptive memory.

In some cases the deposit build-up will restrict air flow so much that if battery power is lost (adaptive memory is lost) the vehicle will not idle afterwards. The solution is to clean the throttle body as specified in the appropriate service manual.

Technicians are advised not to disconnect the battery unnecessarily, especially when clearing diagnostic trouble codes from the ECM's memory.

SUMMARY

1. Use the scan tool to erase diagnostic codes, versus disconnecting the battery.

2. Whenever the battery is disconnected, allow the vehicle to idle for at least 10 minutes. This will allow the ECM to re-learn its adaptive memory.

3. If a vehicle will not idle after the battery has been disconnected, clean the throttle plate.

4. Do not assume that an ISC failure exists if the vehicle will not idle properly after the battery is disconnected.

 

[iaintmaci]

When you disconnect the battery, you are resetting the ECU. Any time it is disconnected from power, it will lose its memory. That is why the car will need to idle for a while after the battery is reconnected. It will have to relearn the proper parameters to efficiently run you particular vehicle. The ECU is flashed to run a vehicle with a specific set of parameters. In order for it to make your car run to meet these specifications, it will need to adjust different parts of the engine. The only way it can learn this is to let the vihicle run for a period of time.

 

[mik3ripp3r]

I hadnt done this with my spare ECU (because it dosen't start with THAT one {I was kind of hoping for a paperclip in the hole for 20 seconds pushbuttony sort of reset}) ..... but, besides that, I have put in many of Idleing hours with the one that does work.....and still nothin...... I truely hope its just an o2 sensor or the coolant temp sensor... every morning when I start it up I just take off immediately without letting her warm up just so I can feel what it used to be like again.....and it is smoooth!

 

[kleenf4i]

When you disconnect the battery, you are resetting the ECU. Any time it is disconnected from power, it will lose its memory. That is why the car will need to idle for a while after the battery is reconnected. It will have to relearn the proper parameters to efficiently run you particular vehicle. The ECU is flashed to run a vehicle with a specific set of parameters. In order for it to make your car run to meet these specifications, it will need to adjust different parts of the engine. The only way it can learn this is to let the vihicle run for a period of time.

maybe true to relearn.. but worth a shot. just trying to help

I hadnt done this with my spare ECU (because it dosen't start with THAT one {I was kind of hoping for a paperclip in the hole for 20 seconds pushbuttony sort of reset}) ..... but, besides that, I have put in many of Idleing hours with the one that does work.....and still nothin...... I truely hope its just an o2 sensor or the coolant temp sensor... every morning when I start it up I just take off immediately without letting her warm up just so I can feel what it used to be like again.....and it is smoooth!

most likely not the ecu by what you just said.

 

[mik3ripp3r]

1. Use the scan tool to erase diagnostic codes, versus disconnecting the battery.

here is my question about this little piece of advice....... from what I understand... the "scan tool" for the 1G is a FRIGGIN ANALOG VOLT METER" and a paperclip jumper and a keen eye for needle spikes like reading morris code!

and to erase codes, if my greasy pages of my service manual are still legible, it does require disconnecting the battery for about 15 minutes if I am correct..

not that I have any codes nor can I find an analog volt meter anywhere anymore but thats just some useless knowlege (to me anyway thusfar) that I have picked up on my quest...

 

[kleenf4i]

Good scan tools, and diagnostic computers have fittings for obd1 and up. for obd 1 it just doesnt have as depth of a reading on the ecu but will still erase the codes. and Yes disconnecting the terminal is supposed to reset the ecu. But from this bulletin the ram still has residual information that the ecu remembers from the car running last. From the scan tool erasing it, it completely wipes everything.