2000 buick lesabre running problem

[502kdog]

Hi i have a 2000 buick lesabre coustom with the 3.8 engine that has been giving us alot of problems running wise,the problem is the car starts fine when cold but when you get where your going say the store after engine is warmed up,the car dont want to start back up it just chuggss and dies,ive sprayed starting fluid trew the intake and it will start and idle bad for a while and slowly run again and you can drive it home and wont start back all over again..it did this before i replaced the fuel pump,the coil packs,fuel pump regulator,fuel filter,check for vacum leaks,thought the converter was clogged removed it,and finally i replaced the mass air flow sensor and it ran fine for about 6 months and know same problem is back....so i replaced the mass air flow again and didnt work this time does anybody have any suggestions would be great... thank you!!!::

 

[dcraig1000]

crankshaft position sensor

 

[HotZ28]

This could be Crankshaft Position Sensor (CKPS) or the Ignition Control Module (ICM). Have you checked for spark when it fails to start? Either one can cause no spark. Any codes?

 

[1380Ken]

I would guess the ignition control module

 

[redmondjp]

Get the codes scanned and report back.

A decent OBD II scantool costs far less than what you have already spent on parts that you probably replaced needlessly. Car parts are much too expensive these days to "shotgun" a problem.

 

[Enslow]

I agree with the above. A decent scantool that does datalogging should cost you about $300 to $400. It will show you all the engine parameters as it stalls. This way you can get a pretty good idea of what caused the stall, whether it be the CPS, voltage problem, airflow problem, engine misses etc. I use the AutoXray, but there are others that do the same I'm sure.

 

[lkraemer]

502kdog,
If you can get the DTC's (Codes) they can be of help.

I am wondering if you just slightly depress the accelerator when it doesnt'
want to start if it will start and run, but will still have an Idle problem?

You can remove the Idle Air Control (IAC) and do a quick test to see if that
is the problem. It should unscrew the Pintle when you turn on the Ignition.
You will have to screw the Pintle back into the Armature (Stepper Motor),
just don't try pushing/forcing it back in the Armature, or you will need a new one.

Now do a quick test of the IAC - Idle Air Control (Stepper Motor - that controls the pintle to adjust the TB bypass air). It will just take a few minutes of your time.

The instructions on my replacement IAC from NAPA states:
NOTICE: Pintle position in the IACV must be checked before installing in Throttle Body. If pintle is extended too far, damage to the TB may occur.
Compress pintle retaining spring from the pintle (towards the body of the IACV), while turning the pintle CW "IN". Return the spring to the original position, with straight portion of spring end aligned with the flat surface of pintle (Groove), so it prevents the pintle from rotating freely.

So, by using this information you can remove the IAC from the TB, and manually adjust the pintle into the IAC for your test. Now, have someone cycle the Ignition Key "ON" then "OFF" and the pintle should extend. If it doesn't move, keep cycling the Ignition for 4-5 times so see if it ever moves. You may or may not feel and hear it clicking as it tries to drive the pintle. If the pintle unscrews out of the IAC, just use the above information to screw it back into the IAC so that it doesn't extend more than 1 1/16" before replacing it back in the TB. If it doesn't move, or moves once out of 6, replace it.

Note: Several Postings on the forum state that these are good for 70K. I laughed.....But, replaced mine at 68752 after it gave me a fit!

REF:
http://buickforums.com/forums/showthread.php?t=25227


Larry