Ole Ed

Hi all. I'm new here and I dont want to just pop in askin for help and not contribute anything helpful but I HAVE to.
My wifes 92 RS is makin me old before my time. Heres what I'm dealin with.
Son went to town one nite. Called sayin it had quit on him. He had to pat the gas to get it to fire back up and it acted like it had flooded out. Idled really high. Ran rough and sluggish on the way back home. Next day I checked it out and it ran like always, just fine. Then my wife drove the car to a baby shower and thought she wasnt gonna make it home. It died, but would restart. Spit and sputtered. Coughed and belched. But she did make it home. Once again I went to check it out and it would start and then die. Sometime it would idle high and when I dropped it gear it would die.
Now heres what I have found.........
First thing I checked was fuel pressure. 43 lbs with no loss after sittin a few mins.
Pinched off the return line. Pressure increased. Dont remember what it jumped to.
Then on to the coil as I've put several on this car over the last few years. It was good.
On to the ICM. Checked it at the Zone and it checked good. Put it back in and replaced the rotor, cap, wires and plugs. Didnt help.
Pulled the cap back off and checked the pickup coil. Good.
While I was in there I took the ICM to another parts store and checked it again. Good.
Then on to the TPS. Good.
Noticed then that the oil pressure switch was leakin. Thought I had found the problem. Thought that since it was leakin it wasnt holdin pressure therefore it was killin the engine. Nope....Changed it and nothin changed.
IAC. Good.
Map sensor. Good.
Temp sensor. Good.
EGR. Good.
Back to the ICM cause someone suggested that because its gettin really hot when tested it may be bad. Nope. Its good. Pulled new one off the shelf and it got hot when tested.
On to the injectors. Have 12 volts on both side of the injector. This is where I am now. I found that the injectors are stayin energized. There is no voltage drop to allow for the squirt.
Have replaced the ECM. This where it gets frustratin. It runs the same, when it runs. It may go 100 miles or just 1 mile and then it quits and wont start back........UNTIL.......
I found this while checkin the injector voltage. Had my son in the car. He was turnin it over as I was checkin for the voltage drop to allow the fuel to flow through the injector and I accidently poked through the wire and it grounded for an instant and the car fired right up and ran. It died soon after. I once again checked for voltage and once again I shorted the wire and once again it fired up. I told him to cut it off. Then I told him to try and start it. It just spun over. I then took the probe and shorted the wire again. It fired right up.
I thought maybe I had gotten a bad ECM so we changed it out. Now I have a high idle (2200) and no torque converter lockup.
I still have to short the injector wire to make it start but it runs great on the road. Also the SES light flashes on and off really fast when I turn the key on. Cant get ANY codes. Not even an all clear 1-2. Had the Zone hook the scanner up and it showed an error and wouldnt pull codes.
.
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This is where I am at this point in time. I have no clue what to do now. I have never ran into this and no one I've asked has either. Has anyone here ever experienced this? I have searched and searched through a blue million old posts on this site and many others to no avail.

RBob

iTrader: (1)

OK, sounds like two problems now. The rapidly flashing SES light means that either the ECM or the MEMCAL is bad. The MEMCAL contains the PROM, which holds the calibration and program for the ECM. This is the part that you have been swapping into each replacement ECM.

Pop the MEMCAL out and check that none of the pins in the ECM MEMCAL socket bent over. If not then most likely that ECM is bad.

As for the injectors, if they are still the stock Multec units then just replace them. The coils short out with the ECM then being unable to fire them. The coil shorting gets worse as they get hot, just like the symptoms you are seeing.

If you want to pull the plenum and measure them. They need to be 12 ohms or higher in resistance. Any that are lower are bad.

On the V6 board here there is a thread about replacing the injectors. It is current with 5 or 6 pages of posts. Also contains which injectors can be used.

RBob.

P.S. Here is a link to the injector thread on the v6 board:

https://www.thirdgen.org/forums/v6/4...injectors.html

firebird904

The F1ZE injector swap is a great replacement over your stock injectors your car will idle smoother and have better throttle response. My old car had a bad ECM and I had gotten a replacement at Oreilly and that one ended up being junk too. Took it back and got a new one and it ran fine again.

Ole Ed

Update...........
All the injectors check good. All pull 12.2-12.7 ohms.
I checked the prom pins and they are all straight.
This is the second ECM I have tried in it. It does exactly the same as the first replacement.
Only way the car will START is to take a screwdriver and touch a bare spot on the blue injector wire and make it spark (ground?) for just an instant. Then it will start and idle at 2000-2200 rpm.
This leads me to believe that whatever, and from wherever the injector pulse comes from BEFORE the ECM is bad. Wouldnt that be the ICM? It has checked good at least 5 times. AND furthermore, how is it that I can short that wire and make it start and run? Wouldnt whatever is malfunctioning and keepin it from starting and running continue to keep it from running?
I am stumped. Everybody I show the short the wire to make it start thing is amazed.
I thank ya'll for the suggestion and advice you have given. BUT I need more input...LOL...This is drivin me crazy tryin to figure it out.

RBob

iTrader: (1)

Is the SES still flashing rapidly? If so then the ECM is in limp mode, not even running from the calibration. Fix that first then work on the bad running while hot issue.

When you measured the injector resistance, was the engine hot? They can check good cold, but short when they get hot.

If you suspect the ICM, go to a u-pull-it yard and find an 8-pin GM (!! GM !!) module. Doesn't matter if it is from a 6 or 8-cylinder. Swap that in with the heat sink grease and try it. If it fixes the hot running issue can then either keep using that one or get the proper GM one.

RBob.

Ole Ed

SES only flashes one time. When the key is turned on. It comes on and then off in an instant. If you arent lookin right at it you'd never see it come on. Its that fast.
The injectors check good both cold and hot.
The ICM....I dont know what to think about that other than the fact that its been checked at least 5 times and it checks good every time.
Now....As for the "Limp Mode". Is this a PROM issue or an ECM issue? Can the PROM be tested? Explain more please.

Ole Ed

Ok......
Thought I'd come back and give an update.
Had the car fixed for a little over 2 weeks now. I went through 3 different ecm's and 2 different proms. In the process of huntin down a matchin prom for my ecm I ran across this little ole guy that told me it was the icm. I informed him it had been checked. 5 times it was checked and all 5 times it checked good. He laughed and told me it was the icm and walked off. I laughed under my breath and walked the other way. BUT while I was in Auto Zone I went ahead and picked up an icm, just for grins and giggles. I put it in and buttoned everything up and be damned, it fired right up and has ran great since. WHODATHUNKIT?
I ran across the guy a day or so later and told him he was right and asked him how he knew. He told me that the machine they use to check the icm only checks the positive side of the icm and doesnt check the negative side. This is where the injector pulse is "born". Now I dont have a clue if thats right or not but I will tell you one thing.....MY CAR RUNS NOW, it didnt before.
Anyway, thanx for all the help and suggestions.