2000 Bonneville SLE 204,000 miles. I am having a hard and long start problem to the point that it will try to kill the battery. The problem is starting to get worse. I will go out in the morning to warm it up and is feels like it is trying to flood itself out. I will crank like it has no spark and then it will act like its about to turn over and then back to flat cranking. There are times that I have to push the pedal down to get it to fire and a lot of smoke comes out of the tailpipe. I have a cylinder 5 missfire at idle and below 1000 rpms. I have no power loss. The Service Engine Soon light will flash when its cold and will stay solid once it warms up. I also have a bank to rich code, cylinder 5 missfire code, and EVAP solenoid code(will fix that with new part). When I had the motor vac done, the car ran and started great with no missfires at idle, then it gradually got worse and finally back to the way it used to be. I do not want to spend $100 every other week just to keep the car running right.

When I first bought the Bonneville about 3 months ago, it had a missfire and found that the front 3 were Autolite copper and the back 3 were Autolite Platinum. I changed those to stock ACDelco plugs. Cylinder 1's wire was not staying attached to the coil so I replaced the wire with ACDelco wires. I tested the coils and replaced the middle. Took Bonne in for a motor vac. Previous owner replaced the fuel pump and filter 6 months prior to my purchase (or so he says). I have changed the Oil Pressure Sensor when I would hit a bump I would go from max oil pressure to zero. That fixed that problem.

Any help or testing that I could do would be greatly appreciated. I have searched the forums and some are similar, but I do not want to throw parts at it. I would like to takle the problem head on with no bandaids(unless its the motor thats the problem, then bandaid away until replacement). My last resort is to take it to a shop.
Thank you in advance,
Aly

Have you had the fuel pressure tested? (Key on, cranking, and running)

Check the IAC(Idle Air Control)sensor plunger also. It will on the front of the throttle body held in by 2 screws.

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I have had it checked when it was in the shop a month ago for a bearing and chasis parts, but I will have to check it again. They said that the fuel pressure was speratic and thought it had something to do with a replacement line the PO had installed. I had the MAP sensor cleaned when it was at the shop to, but I will have to check the IAC when I get home. What will I be looking for when I check it?
Thank you for the quick response!
Aly

How old does the fuel filter look? All rusty and corroded or does it look new?

Check the vacuum line that goes to the fuel pressure regulator, the FPR is at the end of the front fuel rail, towards the pulleys. Pull the vacuum line and smell the inside, if it smells like gas, the FPR is bad.

The fuel pressure shouldnt be sporadic. I think you are having fuel delivery issues.

The IAC will be all carboned up. Some carb cleaner and a rag will clean up the plunger part, and some q tips will allow you to clean the inside of where the IAC goes. There will be a machined bevel where the plunger sits, make sure that is cleaned as well. Best bet is to clean with q tips until you dont get anymore black junk on the q tip.

Also, have you read this info? Do you know if the upper manifold has been changed to a updated version and also if the Lower intake gaskets have been changed to the updated aluminum version?
engine/topic1061.html

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I have not seen the fuel filter, but the shop said it looked like it was recently replaced. I bought a new one that I will eventually put on because every part I have taken off is a cheap off brand. I have taken the vacuum line off the FPR and it smelled faintly like fuel not strong. I have noticed that my fuel economy has started to go down. Its winter here so I let my car run atleast 10 minutes before I go anywhere, plus the starting issue, and then driving...I am getting about 8 mpg, 125 miles to a tank :( Its like i'm driving my 79 K20 with a nicer suspension!

The PO did change the Upper Intake and it looks new. I think they used the Dorman replacement. The gaskets that are showing through look new as well with almost no grime build-up. I do not know if they replaced the lower gasket and if they did only the Dorman kit then it would not come with those gaskets. I have heard about the exploding intakes (which scares me everytime I turn the key).

Sounds like the FPR needs to be replaced.

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I was thinking FPR, but I was not sure. I am going to check the IAC, FPR, and fuel pressure when I get off work. I will hopefully have some more information later on tonight or tomorrow. Thank you all for the help so far.
Aly

So I want to give you all an update. I was about to perform the fuel pressure test yesterday because I had to buy a new tester. It has been in the single digits and negatives all week and yesterday it was -1 when I was going to test. Went to go start the bonneville when an expolsion happened. Didn't get a full rotation out of her. Luckily no one was near the front of the car so no one got hurt, but it set off the car alarms of every vehicle in my neighbors driveway. Which brings me to this question. Where I work I have access to the acdelco and the dormant replacement. I will also try to do the lower intake gasket. Which one is better?
Thanks
Aly

Well, the FPR was your problem. The APN sleeved replacement is the best, but I'm not sure on shipping to Alaska. I'd call the dealer with your VIN and see if your car was ever fixed under the recall. If not, they might be able to help you out with at least a new FPR, or fix the whole dang thing.

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Bye Bye:

RIP sandrock

Do you have a link to the website that the APN sleeve is located?

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Good link: http://www.ineedparts.com/gm-intake-sur ... d-kit.html

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Bye Bye:

RIP sandrock

Thank you for the good link. I have to call them to get an estimate on shipping. If its outrageous I will ship it to a family member and have them ship it up which is cheaper than them shipping direct sometimes.

Just to give an update. We are now Day 3 on this mini project. The coolant elbows broke off inside their holders, but a propane torch helped them loose. Luck has it that my hands were small enough that I did not have to remove the cross over for the exhaust. YAY! Putting her back together was a breeze until we got to the fuel rail. When we were installing the rail we noticed that cylinder number 4 would not go all the way into the slot. Some muscle helped get it further in, but I have my doubts that I will be able to run it this way. It looks like it is sealing, but I think the explosion bent the fuel rail. It put a kink in the FPR holder which we were able to bend out to replace the defective one. Now my question is....has this happened to anyone else? I know I can get a new GM rail from work and we are going to test the seals on the injection system tomorrow. Just with the key on to see if it holds the fuel...if not then I will push her off to the side until I can afford to get them. Is it best to go with new? or can I use some from a salvage yard (if they are available....). The only things we have left are alternator, belt, air duct for air filter, and then adding coolant and clean out the motor as preventative in case coolant made its way down there. Thank you all again for the help with trying to diagnose this before it blew. I really appreciate it!
Thanks,
Aly

I have a rail for cheap if you need one. Pm me.

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Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 57k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 115k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 280k | Official Bonneville Hauler

Okay, everything is back together. Will not start. Cranks and sounds like it wants to start, but will not start. Checked firing order and its correct. Checked pressure at the regulator....52 PSI with key on, but drops to 0 PSI (1 sec/10 PSI until 20 PSI and slows down under 20 PSI) and builds pressure back up to 52 PSI while cranking. Removed fuel rail and watched the injectors without power. All but one are dripping. Cylinder 5 does not leak at all. Please help...we are running out of ideas.
Thanks in advance

They shouldn't be leaking without power to them. I'm guessing that you are flooding it out like you said in your original post. To disable the injectors while starting, hold the throttle all the way down.

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Andrew - owner/operator of Bonnevilles Unlimited

2004 Bonneville GXP | 60k | White Gold Tricoat | custom built supercharged 3800 hot rod | garage queen
1997 Corvette | 57k | Silver Metallic | Z06 wheels | Date-night Hauler/Parts runner
2014 Town & Country Limited | Cashmere Pearl | 115k | Family Hauler
2002 Ram 1500 Quad Cab Sport | Black| 280k | Official Bonneville Hauler

Ok same car as alybue is describing just I'm currently the one working on it while she is at work. It would not start this morning. killed the battery trying to start hooked it up to my car and tried still nothing. i tried putting it to the floor and it makes no difference. i can hear it trying to fire but it just doesnt want to fully go through with it. i currently have the block heater plugged in to see if that will make any difference (its currently 4 here was -5 this morning) it did this the other day when we got it all back together woudn't start no matter what then when we pulled the fuel rail to check the injectors after putting it back together and trying it fired up perfect without touching the gas at all...it feels so random its driving us nuts! i read somewhere that the coolant sensor could be an issue but thats on models that have one on the radiator (ours does not) my question is if the coolant gauge is properly working and there is only 1 on the car is there any way it could still be the problem? me and alybue were talking about the crank sensor and i lean that way but at the same time...this is an issue only when the engine isn't at operating temperature if it fired up right now fully warmed up then went into a store i could come out and it would start perfectly and quickly.

Still not starting pulled the plugs and they were soaked. im starting to think its either the crank position sensor or the ICM I've had experience with a CPS in a 80's ford but when it quit it just stopped. i put a spark sensor on the plugs and its getting spark but it really looks like its getting it every other rotaion instead of every rotation... I'm stumped. I also pulled the fuel pump fuse to try and get it to clean out cranked till it wouldnt sputter then plugged it back in. sputtering started again instantly but still no full fire i can hear it trying to fire but no bueno. also cleaned the MAF as well as tried while it was unplugged no difference.

When My 1997 LeSabre 3800 series 1 started intermittently quitting on me, it took 6 months to track down the problem to a faulty Crankshaft Timing sensor. When it failed, however, there was no indication of even a single spark/typical sound of an engine trying to fire. It was absolutely dead until it decided to run again. ICM may be a good place to start....Have you pulled the multipin connector to check for corrosion, and also tried to check for loose cables into that connector? I used needle nose pliers, and gently but firmly nudged those wires/pins forward in the connector body while still connected to the ICM, checking also for loose or detached connections...

mrwildroot