Newb 88GT and EGR issue? (Page 1/1)
RSJR MAY 30, 01:48 PM
88 GT with about 76k miles.

I just had a bunch of ignition parts replaced a couple of months ago and that resolved my hard start/no start condition and the car has been running great....

Except, now three times, at highway speeds, the car just lost power and started to slow down.

First time, I was driving at about 75mph for a couple of hours when i suddenly lost all power for about 5-10 seconds. I kept the car in gear and after a few seconds, it came back and I continued on our way without issue. No SEL. The second time was on our way home later that day. Similar situation. I was driving about 80mph and the engine sputtered for about a second and then came back to life, no SEL.

Then I drove it around for 2 months without issue, but not on the highway.

Now the third time last Saturday, went for a long cruise but got stopped by rain and I drove home on the expressway. I was going about 80-85 with the newly repaired cruise control activated and then the SEL came on. There wasn't any change to the running engine so I just kept going. About 10 minutes later, the SEL went off and the car started to slow like the previous two instances. Tac was still showing rpm, I had slowed down to about 55 when it seemed like the engine came back and I was able to hold speed. So I tried to accel back up to 75 or so and as soon as I gave it more throttle (maybe 25%) the engine cut out again, sputtered, backfired badly a few times, until I let off the pedal a bit, and then it was fine again. I put on the hazards and just maintained 45-55 for a few minutes and then I tried again, same sputter and backfire, so I backed off to about 50 and set the cruise. After a few more minutes I was getting closer to my exit so I gave it another test...no issues. It accelerated like normal up to 85 and it drove home without issue. The SEL stayed off during all of the sputtering and backfiring.

Both of these days were about 75 degrees out so not hot at all and engine temps were low.

I recently had the cap, rotor, plugs, wires, and coil replaced. The ICM and pickup coil were not replaced. TAC never died except for when I pushed in the clutch to see what would happen, the car sputtered and died. I let the clutch back out and it refired after a few seconds. As long as I didn't give it too much throttle, it would run fine.

My guess is the pickup coil but I guess it could be the ICM as well getting a bit too heat soaked maintaining a higher rpm.

What do you think,

Thanks,

Bob
fierofool MAY 30, 03:01 PM
The SEL light coming on at highway speed then going off is likely in the EGR system. It could be a bad EGR valve or the solenoid, or the plastic vacuum line has a crack or loose connection.

With the engine cold, pull the vacuum line of the EGR valve nipple. Feel underneath the valve and find the rubber diaphragm inside the top. Press upward on it and with the other hand, cap the vacuum nipple. Release pressure on the diaphragm but keep your fingers in contact. It should not leak down if it's good.

Next, inspect the connections at the EGR solenoid. Especially the small looped vacuum line that's on the solenoid, and it's rubber tube that connects one end to the solenoid. Check the two connections on the end of the solenoid.

If there was no backfire when you lost power, it could be something like a dirty fuel filter or the catalytic converter is coming apart and partially blocking the exhaust system.

To identify the source of the SES light, remove the lighter trim plate. Inside the opening, passenger side, you will find the ALDL diagnostic port. Bottom right of the two rows of terminals, passenger side, insert a u-shaped metal paper clip into these terminals while the ignition is off. Now, turn on the ignition but don't start it. The SES light will begin to flash 1 time then 2 times. This is Code 12 and will be flashed 3 times to signal the system is working. It will then flash other sequences, such as 3 times then 2 times. That is code 32 relating to the EGR system. Any trouble codes recorded will flash 3 times then the system will flash 12 to signal end of set codes and start over again. Turn the ignition OFF before removing the paper clip. Always be sure the ignition is OFF when inserting or removing the jumper.

Write down the codes, go back to the front page of this forum and on the left you will find a Diagnostic Code link to identify the meaning of the code. Be aware that the ALDL image is upside down to what it's installed in the Fiero. https://www.fiero.nl/cgi-bin/main.cgi?ECMCodes

[This message has been edited by fierofool (edited 05-30-2022).]

RSJR MAY 31, 01:29 PM
Not sure where the title of my post came from, I think it was the title of my last post. Anyway....

I wasn't able to get the value of the codes since the light disappeared before I had a chance to check it, which happened at or around the same time as the loss of power. The SEL never came on during any of the power losses.

Fuel Filter is new.

I think since I already changed all of the other ignition components I should probably change the pickup coil and the ICM. From what I have read, if one goes bad, the other is probably soon to follow.

Bob
Gall757 MAY 31, 01:44 PM
The codes are still there even if the light goes off.
RSJR JUN 02, 07:16 PM
I'll check them out.

I went for a drive today to see if it was still acting up and once it warmed up, I didn't run well at all. Within 20 minutes the engine cut out 4 times. Each time it was only for about 1/4 to 1/2 second. The SEL flashed each time then went off as the engine recovered. An interesting addition is that the radio stopped playing when this happened and then came right back. Idle was rough bouncing between 900 and 1100 and of course it dropped when it partially stalled. The voltage meter, while hovering just over 13, it was not still, as the engine hunted around for idle the voltmeter was jumping a bit.
RSJR JUN 04, 01:09 PM
I just checked the codes and I just got 12, so nothing is stored.

I decided to swap the ICM since I had one. The connection from the pickup coil was heavily corroded so i cleaned those up a bit. The old ICM didn't seem to have any or very little heat sink compound/thermal grease on it at all. I cleaned off the plate at much as I could and put some heat sink compound on. I put everything back together and went for a ride.

I didn't really see a difference and a few minutes in to my test drive, the SEL flashed for a split second, the car lost all power, the radio turned off and then it all came back almost immediately, except the time had reset on the radio. The total time the car did this was less than 1/4 second.

After that, for the next 30 minutes, the car worked great.

When I got home I was looking around and it looks like the EGR tube had pulled out of the elbow. That may have been the source of my initial SEL on the highway.
IMSA GT JUN 04, 03:25 PM
Sounds like an intermittent ground issue.
theogre JUN 04, 04:40 PM

quote
Originally posted by IMSA GT:
Sounds like an intermittent ground issue.

Iffy grounds are problem but need to check power side too.

Power loss from just the 2nd post involve Fusible Link A and could be anything.
Why? Direct Runs radio, ECM, F-pump and most of rest of the car.
Cause? From loose connection on power block under C500, iffy Ignition switch, iffy wires and more.

If volt meter is 13-15v running and drops to 12vor less then could be alternator problem too.
But that should stop everything working because many things still run until battery is way low like 10v of less.

See my Cave, Wire Service & rest of section.

Note: ECM won't set "code" for this problem. If you see codes, is often bogus cause by power "Blinking out."

⚠️ Warning: Don't drive until fixed.
Can "Blink out" or die completely w/o other warning @ the worse time. Or cause a fire.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

RSJR JUN 04, 05:49 PM
Grounding problem was also my thought. I looked at the two on the passenger side. The braided cable and the one connected to the battery, and neither showed any corrosion at all. The small ground wire on the left side of the deck lid was also fine.

The car is relatively clean and never has really been driven in the winter or even when wet out. I made sure they were all tight. I checked both terminals of the battery (2019) and no corrosion at all, clean as a whistle.

Then I disconnected the C500 block and what a mess that was. A bunch of old hard black stuff that I think was once a grease of some kind but now was completely dried up. I used electronic contact cleaner on both sides and cleaned it up as much as possible. A bunch of brown nasty liquid came out. Then i plugged and unplugged a few times before locking it all down again. I did notice that the orange fusible link was chewed a bit but I didn't see it break through at all, going to replace it just in case. It was connected to the smaller top terminal under C500.

Put everything back together, realized my brand new rear tire has a puncture, filled it back up, and then let the car idle for 15 minutes. The idle seemed more stable, barely moving from ~900. Voltage on the car gauge was above 13, probably 2/3. I put the hazards on and still got some lights dimming and the volt meter looked like it was going down between 1/2 and 1 volt, but still over 13.

Then I went for a 20 minute drive. All seemed great. No power cuts, engine ran very nice. But it was also much cooler today.
theogre JUN 04, 06:13 PM
C500 and many others use "Bulb Grease" sim/same as Cosmoline that never really dries. might "dry" to touch because often have dirt etc on whatever it protects.
Is used by many external light bulb, relays, etc.

Unlike Silicon it won't run or wash off easy even when hit to wash the car.

if replace, Get new "bulb grease"
Permatex has Bulb Grease in 0.5 oz and likely larger and often cheaper pillow packs.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave