Intermittent broblem in GN87

[buickin87]

Hi,

there is some weird problem in our GN.

The car ran fine all the day and left it in the garage for the night time. Next day I started it an it started immediatelly to run bad, sputtered or so, like only three cylinders were in action and it ran rich. After a couple of minutes it started to run right and I took the car into road. It ran fine all the day.

This has happened now two times, first one happened two weeks ago.

I run with Maftpro and Extender pro chip. The injectors are 60 lb Siemens Dekas.

What would cause this kind of intermittent problem?

Thanks in forward!

 

[TurboBuRick]

Bad connections? Remove and reinstall chip. Also cycle the plugs in the tpro and ecm. Look for corrosion inside ecm plugs.

 

[No disintegrations]

Also could be water or rust on the coil pack plug wire terminals. The heat may be cooking off the water. Check for signs of rust at those plug wires. ( all this assuming the car sits a while and doesn't already have these parts in perfect order. )

 

[buickin87]

Thanks for all people,

There is no rust or something bad things in the ignition cable ends. The all six AC Delco ACR43 plug tips were all black, but not wet, when I pulled them, when the first problem occurred. Quite new plugs... But, Now I have to check the ECM- connectors and the chip for the possible corrosion. MafTpro connectors and pins should be ok, because I replaced the all separate small connector "plugs" in the cable ends for a while ago. Checking them anyway.

By the way, in our GN has the AC Delco GEN II ignition system with separate three coils(as it is) and I have been happy with it. Installed it about ten years ago. I have at a spare Standard made ignition module with the coil pack.

But I will be back, if I have found some visible problems in the ECM and chip connectors and if this problem is still appearing. But, all the additional advises are welcome!!

Thanks,

Buickin87,

Finland

 

[buickin87]

Hi,

I pulled out ECM. There is not any contamination, corrosion or wet in the ECM pins and the cable connectors. Also I pulled out the chip from ECM; no corrosion or other bad things. Everything seems to be fine.

What next to check? As Indicated, the problem is intermittent and thus quite difficult to find so easy.

BR,

Pentti

 

[buickin87]

Hi all,

as I reported about the ECM pins and ECM wire connectors as well as chip pins, there was not any dirt, corrosion etc. To day the car started ok, ran fine immedialley from the start and ran fine all the day, again.

So what would be that intermittent problem occurred two times: after the cool start immediately running bad, very rich and so, but after a couple minutes the engine clears itself? Yes, I have reported these things earlier, but this again.

How about the coolant sensor, IAC?? Only trouble code earlier was: Rich condition.

So, please help me you GN experts!

BR,

Pentti

 

[No disintegrations]

Does it have original maf sensor still? They can cause poor running.

 

[dynoman]

Many times a poor connection is corrected just by unplugging & plugging back in again . If I was checking connections and they appeared ok I would still give them a shot of contact cleaner because sometimes they are oxidized and don't look that bad . I come across this frequently when servicing old equipment at GM . Sam

 

[buickin87]

Hi,

ok,I would put to the connectors the cleaner, thanks! And for earlier answer regarding MAF. There is no MAF in our GN anymore. I run with MAFtPro.

Regards,

Pentti

 

[buickin87]

Hi,

the intermittent bad idle and rich condition lasting a couple of minutes after the start up has probably gone. I pulled out and back in the ECM connectors and the chip an as you proposed to do. Every start up is fine and the car runs fine, it was the invisible corrosion in the connectors. I haven´t put yet the cleaner into connector pins, but I will do that, when I have time to let the cleaner dry before I put back the chip and the cable connectors. I have to be careful with the cleaner.

Thanks for all !

BR,

Pentti