2000 Bonneville Hard/Long Start

[AKTikki]

everything seemed to be tight checked the connectors and pulled it off to check for corrosion... made sure the wires were properly connected. i put some dielectric grease back in when i tightened it back down even (dont laugh) thinking that it fires up fine when hot i took a heat gun and warmed the icm thinking it might make a difference no go...however something to note after sitting all night when i did these things and went to start it for a split second during the beggining of cranking it sounded like it was going to start ( I almost let go of the key) then it went back to turning over and ocasionaly firing without starting. im going to warm up a bit (-1 at the time of writing this) and then go back out to pull the icm and take it to get it tested. Unless someone has another idea...i have feeling if i were to put it into a garage over night although it would be difficult to start im willing to bet it actually would and although it works for getting it running it doesnt cure the problem.

[AKTikki]

i read somewhere about there needing to be thermal paste on these things...there isn't any....have a feeling that this is the culprit...waiting for alybue to get home with my car so i can go test this

[AKTikki]

tested it out (3 times) passed every time....no clue anymore....please help!

[bobjones003]

Did you check the connections to icm

[Alybue2]

He said he checked them and tried to see if they would move in the plastic part of the connector. Everything was tight with no corrosion. The icm is a little dirty so I plan on carefully cleaning it before we put it back on and it feels like there is dielectric grease on the back of the plate. We are running out of ideas. I am about ready to send it to a shop.

[Archon]

Were the leaky injectors taken care of? Anyone with a 3800 that you can swap ICMs and coils with?

[AKTikki]

no the injectors are still on (they are going to be replaced ASAP) but there are some new devolopments. When i put the ICM back in knowing that it almost started after sitting for 24 hours i pushed the throttle down about an inch and it fired up. While it was running however i ended up having to hold the throttle as it was running so rich it was puffing out black smoke. after wasting a 1/8 of a tank warming up (on top of about 45 min of running) it all then sudden cleared up....kinda i had 1 or 2 flukes where the idle would start becoming sparatic and it would die. replaced the IAC (noticed it wasn't working like a new one off the shelf does) we started it back up and it was running fine to a gas station but on the way back (about a 1/4 mile drive each way) it started to be sparatic again. plugged in a code reader and looked at the live data and it gave p1034 (i think) stating that it was receiving no signal for o2 bank 1 let it cool off again fired it up and got no code ever again...although the car is drivable again the gas pedal still has to be pressed in order for it to start. im having alybue test it by firing it up and looking at the IAT temperature while its completly cold. When we were looking at o2 sensor voltages i noticed it said IAT was 44 degrees (it was 5 outside at the time) but even in my head it doesn't make sence cause if it was showing the air temperature as warmer then it is outside i would think that it would run leaner not richer. At this point im starting to think its the MAF since if i remember correctly 02 sensors aren't taken into consideration untill the vehicle is warmed up (right?) and as i stated earlier in my mind a bad IAT reading would make it run leaner not richer (right)? I just wish i had something more then a guess cause we would like to throw the money at the injectors instead of chasing our tails till we fine the culprit and waisting money only to have the problem come back.

[AKTikki]

Were the leaky injectors taken care of? Anyone with a 3800 that you can swap ICMs and coils with?

the closest we have is a 1988 delta 88 with a 1st gen 3800 im not sure if anything on it is compatible.

[Archon]

The injectors have been posted as a known problem, leaking into the cylinders. Get the known problem fixed, and we'll move on from there, if that doesn't fix the problem.

Is the car that you have listed in your profile the same vehicle that is listed in Alybue2's?

[AKTikki]

Is the car that you have listed in your profile the same vehicle that is listed in Alybue2's?

Yes

[Archon]

OK. Takes care of swapping from that, then.

I'd still suggest getting the injectors fixed before moving on. Andrew (Harofreak00) should have some for a very reasonable cost.

[Alybue2]

What is the forums opinion on Bostech fuel injectors? The mechanic that I take my vehicles to for things I cannot fix suggested them. He said try rarely had a problem with them and if they did, they took care of the problem immediately. The code that poped up was P0134, P0449, and P0305. The P0134 does not stay on its in the history now.

[AKTikki]

back to no start as of 5 mins ago (-15 doesn't help) i'm going to let her take mine and if i get it started later i'll plug in the code reader and let you know. I know the injectors are a issue that needs fixed and they will i just don't see them causing the issue of a cold start that we are having. specially in the way it cleaned itself up all the sudden after 45 mins of running so rich i could have spy smokescreen coming out of the tailpipe. it was just to sudden of a change for me to think injectors but if there is something i'm missing i'm willing to listen.

[AKTikki]

O.K so...now all the injectors are brand new and i cleaned the plugs and turned it over with the fuel pump fuse out (to make sure that there is no more fuel in the cylinders) put it all back together tried to fire it....it tried to fire but went back to the same old song and dance....but now that the fuel injectors are officially not the issue the only thing left is crank position sensor, or maf sensor any way to test these things and to know for sure if its one or the other? i don't want to throw parts in it till it works i want to find the problem replace it then shoot the broken part with a shotgun. PLEASE HELP!

[Alybue2]

This is an update for anyone who may have had this problem with their Bonneville and for anyone who was curious about her progress. After some additional testing and reading we decided to change the crank position sensor. We did not have the tools necessary and where she was sitting would have been unsafe( parked on ice). I had her towed to a shop. They changed the sensor and still no start. I had them start diagnosing what the problem could possibly be. They say that the timing chain had jumped 1 tooth. They also said that the Mass Air Flow Sensor was melted and my screen for the throttle body was in pieces stuck in my air filter. They also said that there were pieces in my intake from the screen. The mechanic told me to throw the car away. I however do not think she is unfix-able. It will take me time, but I will get her to run again. I am just weighing my options on how I want to proceed. I can just fix the timing and clean the intake again or buy a junkyard motor with 49,000 miles for $1100 or just rebuild the whole motor. Thank you everyone for the help you provided in this nightmare of a problem.

[Mechtech]

I would do a compression test. Your posts sound like it started with a injector #5 leaking down. Fuel/compression/spark The electronics just modify the basics required to run an engine.

[Alybue2]

We were thinking of buying a junk yard ICM and doing a compression test before starting the tear down of the timing chain. After the shop told me to throw away the car, I trust their diagnosis less because it makes me feel like they wanted my car. Thank you for the advice. Once it warms up a little up here I will break out the tester and give it a go. Cylinder 5 has always seemed to have a problem. My DTCs have always had a miss-fire on that cylinder when the car is cold and when it warms up, it goes away.

[Alybue2]

I know it has been over a month since the last reply, but she is back on the road! It was the timing chain. I took it to a shop to have it done because I really did not have the space or time to work on her for an extended period of time. The timing chain was so loose, the mechanic could turn the cam gear a 1/4 turn before the crank gear would turn and vice verse. I had him replace the timing chain, gears, and dampner along with the water pump and updated aluminum connecting hoses made by Dorman. However, now I have another problem that I need to research lol. At least I can finally drive her again. I wanted to give an update to this forum for anyone who may have had my problem. It can be frustrating when you cannot find the answers you want because someone did not update the final outcome. Thank you for all your help.

[mrwildroot]

I know it has been over a month since the last reply, but she is back on the road! It was the timing chain. I took it to a shop to have it done because I really did not have the space or time to work on her for an extended period of time. The timing chain was so loose, the mechanic could turn the cam gear a 1/4 turn before the crank gear would turn and vice verse. I had him replace the timing chain, gears, and dampner along with the water pump and updated aluminum connecting hoses made by Dorman. However, now I have another problem that I need to research lol. At least I can finally drive her again. I wanted to give an update to this forum for anyone who may have had my problem. It can be frustrating when you cannot find the answers you want because someone did not update the final outcome. Thank you for all your help.

Thanks for the update!
I have been wondering how this turned out for you.
Smart to get all that maintenance done too!

Enjoy your driving experience! You earned it!!!

MW

[Archon]

AFAIK, this is the first reported problem that has been reported with the timing chain in this generation.