The Oldsmobile Connection

[obiwann]

as per my other post i changed my coil pack and ignition module from a 93 buick that had a 3.8 , but my problem still persists, once the car is warmed up when i step hard on the gas like to pass someone, it goes into passing gear for a second or so then starts jerking around, if i let off a little it smoothens out but it eventually stalls. if i wait for like 30 seconds it starts no problem and away i go. i got a mass air flow sensor from the same car but the numbers on them are a little differant . from my car an 94 delta 88 the numbers are afh50m-03 and underneath that is 4416 where as from the buick the numbers are afh50m-o2e and underneath a2y12 my question is can i use the one from the buick in my car?? also does anyone have any other ideas what my problem might be? the car runs perfect when it's cold, like for 20 minutes. any help would be appreciated

[91parkave]

did you make sure the icm module harness is intact and properly tightened? Have you tested the new ICM you got to make sure its in working order as well? also ensure the ground wire on the underside of the Bracket is intact and cleaned off and tightened, as for the Mass air flow im not 100% on it, ive switched around from various years without a problem, feel free to try it out, it wont hurt anything by trying, if your PCM dosent like it, it will throw you a code anyway. Best of luck

[obiwann]

thanks for the reply parkave i didn't know there was a ground wire under the bracket. i'll go check it out and clean it up. then i'll get the icm i took out tested just to see if it's ok then switch and get the other one tested.then i could have a spare. could a mass air flow sensor be causing my problems? would it not be screwing up all the time and not just after it's warmed up and under hard acceleration from like 50 mph up, would it cause my engine to eventually stall. thanks for the info.

[91parkave]

On most of the 91's-95's there were ground wires however i have seen a couple with out them, as long as the bracket is clean where the ICM contacts the bracket and where the bracket attaches to the cylinder head you should be fine on the ground issue, As for The maf, per say if it was bad it --should-- throw a code but not always, you can always clean the one you have now and see. When my maf went out on me, i couldnt go past half throttle or pass anyone without the car bucking and going nowhere, but its always a case by case issue, Since you already have the spare MAF, clean it up and throw it on , But reset your PCM first by leaving the battery disconnected for 30 minutes, or overnight. and see if that helps.

[obiwann]

thanks parkave to clean the mass air flow sensor do you mean the two little electrodes arent't those very sensitive how would i go about cleaning them. i also found a broken wire which ran from the icm wireing harness along the firewall to under the dash(i think its for my command start ,does that sound right , i don't know how they hook those up, it was spliced in to one of the wires) havent taken the car out so i dont know if it did anything. going to go get my original icm tested tomorrow and see if its good then i'll know i have to look somewhere else. cause maybe the one i put in is no good too. thanks for the input

[88 Coupe]

Most of this was already covered here. Hard to follow because of the hijack/trashing by 91buickman, so here are the relevant parts, again.

obiwann wrote: ........ i didn't know there was a ground wire under the bracket .........
All electrical components must have a complete circuit in order to function. In automotive applications, the negative side of a component, is is usually grounded through its attachment to the body, or frame.

Many times, a "faulty" part, can be "fixed" by simply removing and replacing it. This is what leads "experienced" posters (like 91buickman) to, mistakenly, believe the part was the problem. It also, partially, explains why there is so much bogus advice on the Internet.

obiwann wrote: ........ could a mass air flow sensor be causing my problems? ........
Not according to the symptoms you described.

obiwann wrote: ........ just after it's warmed up and under hard acceleration ........
This tells us, the problem only occurs after the system is in "closed" loop, and when WOT (wide open throttle) returns it to "open" loop.

Or, that an electrical (or electronic) component is overheating.

obiwann wrote: ........ from like 50 mph up ........
This would indicate a malfunctioning "speed" sensor, if it did not "go away" when the speed fell below 50 MPH.

obiwann wrote: ........ would it cause my engine to eventually stall.
No.

If any component (other that the coils/crank position sensor) fails, the "loop" opens, all sensors (except the crank position sensor) are bypassed, and the the computer uses its default program to run the engine.

Assuming your replacement coils (you did test them, didn't you?) are good, look for a loose or faulty ground, or a fault in the wiring harness.

If there are still no stored codes, the computer itself becomes suspect.

The more accurately you describe the symptoms, the closer you will be, to pinpointing the source.

Norm

[91parkave]

anyways you mentioned that broken wire, does your car have a aftermarket alarm system? remote start? oh and the maf can be cleaned very easily, with MAF cleaner spray from autzone or you can use rubbing alcohol on a cutip and very gently clean the MAF wires, But first things first id check the ICM wiring and repair that broken wire

[obiwann]

yes i do have a aftermarket remote start (command start) when they install it do they run a wire from the icm wireing harness? because like i said the wire runs along the firewall to under the dash on the drivers side(thats the one i fixed) i had the car out tonight its runing perfect. i'll take it for a longer run tomorrow and see what happens. i also cleaned up the bottom of the icm and the grounds. i'll let you know tomorrow what happens. haven't changed the maf sensor yet.

[Brando]

obiwann wrote: yes i do have a aftermarket remote start (command start) when they install it do they run a wire from the icm wireing harness? because like i said the wire runs along the firewall to under the dash on the drivers side(thats the one i fixed) i had the car out tonight its runing perfect. i'll take it for a longer run tomorrow and see what happens. i also cleaned up the bottom of the icm and the grounds. i'll let you know tomorrow what happens. haven't changed the maf sensor yet.

Yes, that would be the tach wire for the remote start....senses when the engine has started and tells the remote start to stop cranking. Usually taps into the ignition coil module harness, or a fuel injector.

Was it connected to the purple/white wire in the harness?

TOC Admin
Brando

[obiwann]

ya brando it was connected to the purple/white wire so i guess that is what it is for. cleaned my maf sensor today then took car for a run and it jerked and stuttered the first couple times i stepped on it then after that it didn't happen again,ran good the rest of the day.we'll see if it stays like that, hopefully it will. tried to get my original icm tested today but sofar there no place in town that can do it . thanks for all the help guys i'll let you know in the next few days if my car acts up again.

[88 Coupe]

http://www.oldsconnection.com/forum/viewtopic.php?p=24281#24281

Norm