89 Pontiac Bonneville LE cranks but no start

[TrappingSouls]

Hello I have a Pontiac Bonneville that i bought and was running when I bought it. When I got the car home I decided to do a little work on it a started by changing the oil and the transmission fluid since when I checked both they smelt burnt and black smoke was coming out of the tail pipe when running. So after replacing the oil, oil filter, in pan filter(forgot what it's called), and the oil pan gasket, also replacing the transmission fluid and filter and gasket. I also replaced that spark plugs and spark plug wires. The black smoke was gone and was light and white. I also decided to replace the fuel filter just in case it was full of dirt since the car was from an impound lot and was sitting for a while. So, after all of this the car started to run badly it lacked power when accelerating from a stop light and would sometimes die when sitting in park it also idled up and down by its self being in any gear. So, I checked the check engine light code and was given two of them 41 34 . So I replaced the mass airflow sensor which wasn't hard at all then I get to the cam position sensor. which wasn't hard to get to like I have read on the forums I didn't need to remove the harmonic balancer to get to the cam position sensor. So with all that replaced the car still had the same problems just the code 34 was no longer coming up. Me not know too much about cars didn't know that the cam position sensor also has the interrupter magnet so now I bought all the items to replace that which was totally broken and I found the small magnet stuck to the timing cover and the broken plastic housing still in the hole on the timing gear. I also decided to replace all the battery and ground wires since the car looked like a troll wired it and the battery terminal cables had a bunch of bare spots since someone used what looked like to me power line cable for battery cables. luckily everything went well and didn't have any issues replacing any of the gaskets and what not. thinking that the car was finally fixed after all this work I decided to take it for a drive. the car started great you could barely hear it crank and it started instantly so I drove it around town and check to see if it would have problems like it did before which it didn't it did well at stop lights and on hills and it sat and idled without a fluctuation in RPMs. After driving for about a half hour being the first time I could actually drive my *NEW* car I checked the codes again and nothing came up (YAY). so thinking everything was fine I turned the car off. The next day I went to start the car and it wouldn't start at all. The car cranks normally and doesn't sound like anything is out of place or abnormal. so I start checking what could be wrong so I check to see if it's getting fuel to the injectors which it is then I checked to see if spark plugs were getting a spark and come to find out they are not. being totally stumped I check to make sure that the magnet is still there which it is and just in case I got faulty parts from the shop I replaced them again and made sure that everything was properly installed. With everything replaced again and everything double checked to make sure it is correct the car still doesn't start and the spark plugs still don't have a spark so I took the ICM and coils in to have them check to make sure they are working also took the alternator in to have it check just to make sure it was okay too since I was there. I had them run the test 15 times just to make sure and all three parts tested good all 15 times. so after I put all the parts back on the car I came back to this forum and saw that someone said that checking the ICM harness wires for voltage is a good idea. which I did and the voltage read 12.9 volts in the wires. the wires look fine and the connectors look fine except the big bar one with the bolt in it on the front of the ICM a few of the female connectors seem crushed(which either I don't know the proper name or they don't make this item) but I can't find a replacement. but to me that doesn't seem to be a legit problem to why one night it ran perfectly and then the next morning to wouldn't. please if anyone can give me some help that would be much appreciated I really need this car to run being it's my only mode of transportation and my first car. I have almost read the complete forum for my year and have tried everything that I found so far with no success. Sorry for such a long report but I wanted to let you all know what all I have done and what all I have experienced

[MattStrike]

Get a new ICM wire harness from a junkyard and do a continuity test to make sure it doesn't have any broken wires (or at least the ICM connector with 5-6" of the wires). While you're at it, if you haven't already, upgrade to the type-2 (Delco) ICM with 3 individual coils.

Any squished female connector terminals are certainly making at best an intermittent connection, and the work you did may have bumped things around just enough that after cooling down they are not making the connection.

Also double check the wires between the ICM and the crankshaft posistion sensor with a continuity test. Wires can break inside of the insulation and the only way to know for sure is the continuity test.

[TrappingSouls]

Thanks for the response. The car has a coil pack with 3 individual coils and the ICM wire harness plug has a couple bad female terminals which I went out a bought new ones to replace the ones that looked bad ( the curved spring like piece inside is either squished or missing ).

As far as the continuity test I am unsure how to do that. I do have a volt meter, I just not sure what to set it to. When doing the continuity test for the crankshaft position sensor would I put a pin in the wire at the sensor and the ICM plug and check it or can I unplug both and attach the probes that way.

Also we thought it might have been the ECM at the start of all of this and I bought a new one since code 41 means 3 different things to this type of car and engine but when the car ran after all this work before it decided not to run again the old ECM was attached to the car. So I'm wondering if maybe if I have to try and pull the whole harness for the ICM out of the fire wall to check it since it connects to the ECM.

There are a lot of junk yards in my town and I have gone there looking for replacement parts already ( front and back light lenses and the grill ) with out any luck and they dont have the car it self but they have the same engine but a lot of the ones they have, they have had for a while and a lot of parts are already missing. So becaise of that I am wondering, if I find a wire that doesn't carry electricity can I just replace that one wire ( or more ) and if so what kinda of wire would I use to do so. Thanks

[TrappingSouls]

Okay I finished a continuity test on all the wires on the ICM harness and for all the sensors and everything turned out to be fine i did find a few female terminals that were bad and i replaced those and i checked the continuity again and everything was still perfect.

is there something else that i can try or to check that might be wrong and what is the likely hood that the ICM and/or coil could test a false positive that many times since i have heard someone in the forums say that it happens sometimes

the car will still not start and i am at a total loss of what could be wrong i have tried everything that i knew of and what others have said to try and everything turns out to be fine unless there is something else im not thinking of or something that i might be missing

[MattStrike]

You tried swapping the computer? There are only four possibilities: Computer, ICM, crank sensor, and wiring. If you had two bad coils it wouldn't start, so that would be the only other thing I could think of that would cause no spark.

(sometimes) it makes sense to have a spare computer and ICM to help rule these things out when you have these older cars.

Oh, just thought of something else... Have you check all the fuses? I always forget to check the simple things first.

[TrappingSouls]

I have checked all the fuses under the steering column and all of them are good and the correct amp (now) if there are other fuses else where I don't know where they are.

I had the coil pack and the ICM tested separately and they tested fine but I know that they can test a false positive sometimes so I can test the coil my self and take the ICM back to test it since I don't have the connector.

I'll try this stuff out and tell you how it goes might be a while because the computer takes forever to order for some reason.

Thanks again

[MattStrike]

No junkyards in the area to grab the spares from? Computers are terribly expensive otherwise. I think there is a fuse center under the hood, center of the firewall above the blower motor. AFAIK, that fuse center under the hood is only absent from the '85-'87 C/H-body cars.

[TrappingSouls]

okay i looked for a fuse box in that area then looked everywhere else in the engine and i didn't find anything that was like a fuse box all i found where you said it should be (after removing the firewall cover) was a long rectangle red box with the word battery on it with a lot of wires coming out of it (no fuse in there) and 2 small black boxes (1"x1"x2") with 5 wires coming out of each that says Hella on them also found a few more in other parts of the engine compartment (from my understanding those are relay switches i don't know i could be wrong) but i googled search where the fuse box is under the hood for my year and type of car and didn't find anything that helped and tried searching for pictures and didn't find anything close to starting to help i am so at a loss right now is there a way you could find a picture or something maybe cuz all that's above the blower is a big black box with 2 vacuum lines coming out of it

Sorry if i seem to be totally ignorant but this car has been trouble since day one

also i thought that car computers needed to be specific to the car and VIN i didn't think you could just put another one in it with out it being formatted for the car and the junk yards don't have my car but they carry the Buick which have the same type of engines so i can try to at least look for a ICM for now till i know for sure about the ECM

[Mechanical Mike]

The ICM grounds through the mounting bracket. Try removing the ICM & the mounting plate from the mounting bracket. Clean all the corrosion from the mounting bracket, both sides of the mounting plate & the bottom of the ICM. Lightly coat all 4 surfaces with dielectric grease & reassemble.

PS - There are also fuses & relays under the dash on the passenger side. You should have 12 volts at terminal P (pink/black wire) of the ICM wiring harness while the key is in the run position. You may have already checked this but check it again.

[MattStrike]

there is a tag on the ecm, starts with 122xxxx As long as the new ecm has the same number it will work. But you have to swap the PROM out - there is a small cover bolted to the pcm and the prom is on a removable chip under the cover.

[TrappingSouls]

thanks Mechanical Mike for your advice but i have done all of this already cuz i noticed when i removed the ICM while trying to rewire the female terminals for the plug that there was a lot of corrosion on it and i used sand paper and a razor blade to clean it i also noticed that the bolts on the ICM were rusted and looked bad so i cleaned them the best i could and i used the dielectric grease on as much of it as i could.

I will check the pink and black wire again to make sure it still has power but last time i did it did

also i have been trying to get to the passenger side fuses and being a big guy like i am its kinda hard to fit myself under there but i am still chipping away at it
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MattStrike thanks for getting back to me there once was a tag/sticker on the ECM but it looked like it was so dry rotted that it just fell off and not sure where it went but i think i have it somewhere and i haven't been working much since the hours got cut and the extra money i had to work on the car isnt here till i start working more im hoping that i can get it started back up soon or im going to have to sell this car for as much as i can get for it which probably wont be for how much i have in it as of yet but i will try to keep you all posted on how the work goes also i have a picture of my engine compartment i didn't know if maybe you could take the photo and maybe mark where the fuses should be and then i can take a close up picture if i don't find it there so maybe you can see what im looking at too

[MattStrike]

Any H-body (Buick, Olds, Pontiac) should have the same pcm, including the C-body, if it has the same engine. Your junkyard should be able to look up/print out an interchange. The big thing is to remember to change out the PROM once you do get it.

I see you still have the Magnavox ICM. You will want to switch to the Delco ICM/coils. I would not get another Magnavox ICM/coil if you have to get a spare.

[TrappingSouls]

well the picture isnt one i took it is one that i found but i will take a picture and upload it to this site so you can see what i am working with.

i noticed you marked the picture so i will take a close up of that area so you can see what is there cuz i looked there and there isnt any fuses as far as i can see. i am not sure how to tell the difference in the ICMs and i went to auto zone and they act like they don't know a thing and pep boys acted like i was crazy since they asked me 4 times what an ICM was and when i told them they said they don't carry stuff like that. i don't know of any good sites to get parts from so maybe someone can suggest some for me i am about done trying to convince my self that auto parts stores are helpful.

this is my ICM/coil pack


this is a picture of my engine


this is a picture of a close up of where you marked the other picture


and this is whats reveled when the fire wall cover is removed (the black things which i was told are relays and the red box which is the junction box from the positive post on the battery) are there supposed to be fuses here


also i was told that if i give out my VIN when talking to car gurus that it may help a lot with getting info that i may be missing to tell you guys so here it is

VIN: 1 G 2 H X 5 4 C 8 K W 2 8 8 1 3 0


i hope this new info helps still haven't gotten to the fuses on the passenger side under the glove box but am still working on it

[MattStrike]

Interesting. I thought my '89 had the fuses & power distribution center under the cover. I'm sure it did. Anyhow, no fuses there to check on yours.

But still a magnavox ICM & coil pack.
http://www.pontiacbonnevilleclub.com/fo ... c1684.html

[pontiacsteve22]

Just wanted to say on my 1990 model i found fuses and relays behind the glove box. Open the box up and pull the tabs in the back and then there are a few 7mm i think screws under the box and remove them and then you have perfect access tp the panel.Thats where my fuel pump relay was,NOT under the hood under the black panel on the fire wall.Sometimes what the manual says is not always correct, maybe the factory shop manual is always correct but not the chiltons,I was fooled too, i did alot of work in february and made a DUMB mistake and forgot to tighten the ecm (computer) ground under the coil pack which sits on the icm.And for a month the car ran perfect then one day it started to stall??? A mobil mechanic which was a very HONEST guy took about close to 2 hours until he found it.This guy could not find a ground at the panel, and then he was stumped but than we started to dig around the area under the icm, and bingo all was solved.When you do a ton of stuff at once, there is always a chance to forget one little thing.I used to race Motocross back in the days, and still today i ride and triple check my stuff.But on a dirt bike there is not a million of things on the bike.So maybe check the area i had a problem with, and i hope you get going ASAP.Best wishes and take care.