89 Bonneville - Dies

[Necronomikron]

First, I will do a quick recap of the recent history of this vehicle.

It has been sitting for approximately 5 years, just now decided to start fixing it up. I have done the following:

Replaced Oil
Replaced Oil Filter
Replaced Transmission Fluid
Replaced Transmission Filter
Replaced Battery
Replaced Fuel Filter
Replaced One of the Vaccuum line elbows.

I have not tested the vaccuum lines extensively.

Right now, it will start and run, but sporadically either lose power, like it skips a beat, or simply die. I'm confused as to the cause, and was hoping that the fuel filter would fix it, but I replaced it today, and it is still having the same problem. It does seem to get progressively worse as I drive it (from a cold start).

Any ideas? I am aware that it could be the fuel pump, but I'm told that it's in the gas tank, and I'd like to test other things first.

[randy78]

MAf sensor may be the culprit and they are known for failing

supposedly the test for these is to start it up and tap on the MAF housing with a screwdriver handle or similar and see if the engine misses or stumbles or anything

if so then the MAF is bad

also make sure the engine dies when you unplug the MAF


if not then check ignition module, and try another 02 sensor

are there any codes ?


test fuel pressure to rule out weak pump


usually weak pump will cause hardto start, extra cranking to get it started


but so can a failed fuel pressure regulator

the dealer can connect the car to the computer and find out what is wrong for 40 or 50 bucks


good luck

[Necronomikron]

Originally Posted by fastr68

MAf sensor may be the culprit and they are known for failing

supposedly the test for these is to start it up and tap on the MAF housing with a screwdriver handle or similar and see if the engine misses or stumbles or anything

if so then the MAF is bad

also make sure the engine dies when you unplug the MAF


if not then check ignition module, and try another 02 sensor

are there any codes ?


test fuel pressure to rule out weak pump


usually weak pump will cause hardto start, extra cranking to get it started


but so can a failed fuel pressure regulator

the dealer can connect the car to the computer and find out what is wrong for 40 or 50 bucks


good luck

I have a friend who has the machine to check it, but doesn't know how to really operate it (he bought the one for older machines and the one for newer ones, and has only operated the one for newer machines). I'll see if we can get a code.

From a cold start, it seems to start up quite well.

I'm not particularly mechanic-minded, but I'll forward this information to the person helping me.

Thanks, I'll post back.

[jdq]

What about plugs and wires, also is your SES light on right now , if it is you could read the codes with a paper clip.

[Necronomikron]

Originally Posted by jdq

What about plugs and wires, also is your SES light on right now , if it is you could read the codes with a paper clip.

I have new plugs and wires waiting to be installed. Yes, the SES light turns on.

Tapping the MAF sensor caused the system to almost die... noticed a crack in the housing (plastic that holds the electronics) that I put silicon on. Not sure if its faulty wiring or bad sensor.

[maxwedge]

More than likely the maf is bad if it fails the " tap" test.

[jdq]

You can retrieve your code using a paperclip or some metal pin on these years.Just touch the ends of the paperclip to the 2 uppermost pins on the right side of the ALDL connector (where you would hook up code reader) turn key to on position without starting engine.Using your SES light on dash you count the flashes.It should first flash once and then twice for a code twelve, it will do this 3 times.After this code twelve count the flash sequence and these are your actual codes, for instance
flash flash flash and then stop (3 flashes)
flash flash flash flash and then stop(4 flashes)
This is a code 34 which is maf sensor.
Remember it will flash each code 3 times and when it flashes code twelve again you have no more codes stored.Report your code back to us and we will let you know what it is.

[Necronomikron]

Originally Posted by jdq

You can retrieve your code using a paperclip or some metal pin on these years.Just touch the ends of the paperclip to the 2 uppermost pins on the right side of the ALDL connector (where you would hook up code reader) turn key to on position without starting engine.Using your SES light on dash you count the flashes.It should first flash once and then twice for a code twelve, it will do this 3 times.After this code twelve count the flash sequence and these are your actual codes, for instance
flash flash flash and then stop (3 flashes)
flash flash flash flash and then stop(4 flashes)
This is a code 34 which is maf sensor.
Remember it will flash each code 3 times and when it flashes code twelve again you have no more codes stored.Report your code back to us and we will let you know what it is.

Well, I hooked up a reader to it, and it was getting Code 34 MAF Sensor, I replaced the MAF Sensor, and it seems to be riding quite well, however, it was getting, before and after, a QDM Error as well... still getting that, but it drives just fine. A quick google search indicates that it has something to do with the computer not getting the proper voltage from one of the sensors or components...

The MAF sensor was replaced by a junkyard special, if that matters.

Plugs and wires have been replaced as well, today.

[jdq]

There ya go looks like you found the culprit.
The code 26 quad driver module I think is related to a few things like Torque converter clutch, fan relay ,evap solonoid and cannister and a few more.Possibly connectors .

[Necronomikron]

Oh, and thanks guys for helping me!