2001 4.3 v6

volfan · March 22, 2005

i have a friend with a 2001 2wd with 50 k that just started running rough and acting like it does not want to start .the ses light as also flashed at times for a few minutes and also stayed on solid for awile then goes off took it to autozone but didnt give him a code when they checked it.thought it might 02 sensors but hes starting with plug replacement today any help is appreciated

Cool Zr2 · March 22, 2005

It won't be o2, it will start and run in limp mode of a sensor is bad, and for the first few minutes it dosen't use the o2 sensors anyway.

Autozine f'ed up, go to the dealer and have them look at it, timing could have jumped, sensor issures, coil issuse.

If he just starts replacing things untill its fixed he is going to be broke. Thats a foolish and bad idea on a vortec motor. The Tech 2 will find the problem and the dealer will fix it for a fraction of the cost of "guessing".

fig03 · March 23, 2005

I had the same problem with my 01 4.3 ECSB it was the distributor cap

volfan · March 23, 2005

thanks guys i think he is going to get it checked out by qualified personnel he just thought he might hit the fix by changing the plugs but that dint work.is there some chance a fuel pump or some fuel system component could case the off and on spittin and sputterin.thanks guys for all your replies

Cranky1 · March 23, 2005

Sounds like you could have a few things happening. Cool Zr2 is right that you should take it to a dealer or a good mechanic. The process of elimination can be more expensive in the long run. The SES light and the hard starting could be 2 seperate things all together.

The ruff idle could be the EGR valve, you will get a SES light and code as the truck is warming up, a lot of times the code for a knock sensor will come up if the EGR is acting up, this doesn't mean that the knock sensor is the problem, just that it can't retard or advance the timing to get the engine to smooth out. Process of elimination would be to replace the knock sensor ($75) wrong!

The hard starting could be the begining of the fuel pump on it's way out. You would need a fuel pressure gage to see if your getting enough pressure to start the truck. I have seen an engine start with 50lbs of pressure and fail to start at 48lbs. The ruff idle could be low fuel pressure also. A good mechanic can peg this problem in the 1st hour. This is a great site, but spend the $75 and let the mechanic tell you what the problem is the 1st time.

sjspor · March 23, 2005

Distributor Cap and rotor... and a new Distributor. While your at it, tighten your oil pan bolts, by 50K you have loose ones.

Here's the bullitin. Bulliting #03-06-04-041 published on 08/26/2003.

-------------------------

Poor Engine Performance - Misfire, Rough Idle, Service Engine Soon/Check Engine Light Illuminated, DTC P0300 Set (Inspect DIstributor Ignition (DI) System Components and Replace As Necessary) #03-06-04-041 - (08/26/2003)

Poor Engine Performance -- Misfire, Rough Idle, Service Engine Soon/Check Engine Light Illuminated, DTC P0300 Set (Inspect Distributor Ignition (DI) System Components and Replace As Necessary)

2001-2003 Chevrolet Astro, Blazer, Express, S-10, Silverado

2001-2003 GMC Jimmy, Safari, Savana, Sierra, Sonoma

2001 Oldsmobile Bravada

with 4.3L, 5.0L or 5.7L Gas Engine (VINs W, X, M, R -- RPOs L35, LU3, L30, L31)

Condition

Some customers may comment on poor engine performance and the Service Engine Soon/Check Engine light being illuminated. Upon investigation, the technician may find DTC P0300 set.

Cause

This condition may be due to high levels of internal corrosion in the distributor, causing spark to go to the wrong cylinder. This corrosion is attributed to a lack of air flow internal to the cap caused by the EIP screens being clogged with debris.

Correction

Inspect the internal components of the Distributor Ignition System using the procedure listed below. A new distributor base has been released for service with improved airflow screens.

Inspect the distributor cap. You may notice a white residue on the cap walls. For higher mileage occurrences, the interior of the cap may have changed to medium brown in color.

Inspect the distributor rotor. You may notice the presence of black streaks on the plastic surface. More typical evidence would be visible green spots on the copper surface of the rotor segment.

Inspect the distributor base. You may notice high levels of surface rust on the distributor shaft or surface contamination on the sensor hold down screws.

Inspect the distributor EIP screen. The screens should be free of any debris and the mesh should be visibly porous.

All of these inspection can be done on-vehicle. If there is evidence of this internal corrosion, replace the affected component. Refer to the appropriate procedure in the Engine Controls sub-section of the applicable Service Manual.

In addition, it has been determined on the Sierra and Silverado applications with the 4.3L engine that the A/C accumulator line is routed directly above the distributor area and condensation from that line can aggravate the corrosion condition. For these vehicles, install the foam sleeve, P/N 15190971, to the A/C line. Cut a slit in the sleeve and secure to the line using tie-straps.

Parts Information

Part Number

Description

10452458

Cap, Distributor (V6)

10452457

Rotor, Distributor (V6 and V8)

93441559

Distributor (V6)

10452459

Cap, Distributor (V8)

93441558

Distributor (V8)

15190971

Foam Sleeve

volfan · March 29, 2005

buddy finally took truck to gm dealer but first he let a shadetree replace dist cap and rotory but he acted up again and then he took to gm dealer tech said he neede to have dist cap and rotary replaced because there was acertain way you had to make sure the distributor was set in place and shadetree didnt do that so dealer repaced cap and rotary with genuine gm parts well today buddy went fishing drove approx 120 miles with boat and truck ran fine used 1/4 tank but on the way back started sputtering again with ses light and used 1/2 tank of gas to get back.so hes going back to dealer tommorrow but whats the deal is it the distributor itself like i think the bullitin above said or something else?