First of all, this site has helped resolve many issues concerning my Blazer. However I have another major issue which seems to be very common with the blazer, however have not found the actual fix for it. ARE YOU UP FOR THE CHALLEGE??? Please reply ONLY if you know, guesses do not help.

OK to the point...

Issue:
My Blazer (1996, 4.3L, 2WD, 2 door, 250K miles) is stumbling at around 2000 to 2300 RPM range, and while cruising at 70 MPH. Sometimes she just flat out stalls. The check engine light comes and goes or sometimes blinks. Otherwise motor is extremely strong, some days she runs like there was nothing wrong at all..

Codes recieved:
I am getting codes P0175, P0172 and P0300

Already fixed/replaced:
Complete tune up - plugs, wires, cap and rotor, fuel filter, cleaned K&N air filter. Brand new Optima Yellow Top. New Drive Belt and Tensioner. Cleaned MAF sensor

Replaced Fuel Pressure Regulator - cleaned throttle body and intake while apart.

Replaced Shift Solenoids in Tranny - both went out about 3 months ago.

 

Yeah, that will bring in a lot of responses. Since none of us can see your truck to diagnose it from where we are, all replies are just guesses.
Have you cleaned the EGR valve?

 

Yes, cleaned the EGR and used a screened gasket, per other posts.

Your right all are guesses, I am looking for someone who may have had this issue and resolved it. It seems like I can find issue everywhere, however never seen the actual resolution.

 

96 blazer, 2wd, 2dr

I have been struggling through P0030, P0172 and P0175, as well as a few other minor issues.

However, now after about an hour of driving, the truck just decides to stall. It can be stopped at a light or while cruising down the highway. Just up and dies - I then have to wait 10 min before it will start again and then it just continually stalls (wait, start, stall - all the way home). If I let it sit over night it starts right up and I can get to work without issue (other than the occasional P0030 stuff) 20 minute trip. The stalling only occurs after running for an hour or more. Short trips under an hour no stalling.

What might cause this Can the Fuel pump be overheating and quitting??

Any suggestions would be great...

Thus far

New
Plugs, wires, cap and rotor
fuel filter
MAF
Evap Purge solenoid
FPR

Cleaned
egr - added screen
2 bottles of seafoam 1 through the tank and 1 through vacuum hose
cleaned intake and injector nozzles while replacing FPR

 

*Merged Threads* - So does this mean that you now are willing to have others that have not experienced this exact problem help you out?

Before I get an answer to that, here are the diagnostic listings for the codes you are experiencing:
P0172 - Fuel Trim System Rich Bank 1
P0175 - Fuel Trim System Rich Bank 2
P0300 - Random/Multiple Cylinder Misfire Detected

 

yes, and I did appologize, I was just frustrated with the truck, that evening.

I do have an update though, after reading several other posts, I decided to pull my cap and inspect it.

Sure enough I have alot of not so much burn spots but white spots on the terminals. I am using a wire brush to clean them and will try again.

I just replaced this think like 2 months ago

 

Sounds like corrosion residue. While it does not specifically address your year truck, this TSB might be of help to you.
-------------------------------------------------------------
Bulletin #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


Parts are currently available from GMSPO.

 

Ok, so yesterday I cleaned the cap and rotor to remove all oxidization - no help, actually seemed a bit worse.

So today I decided to pull the distributor - all of the teeth have fresh shredding and completey shiny on one side of them (I mean there is a measurable amount of metal missing) - I added pics - they are a little hard to see but the shiny teeth speak for themselves.

So 2 questions come to mind

1 What can cause this?

2 What is the possibility of the meshing gear within the motor also being bad? And if so, the fix?

Thanks for the help!!!

 

Yeah, that does not look good. The gear on the back of the cam is made of a harder material than the distributor so you should be fine down there.

Is the wear even on all teeth?

You can get just a new gear, but I would inspect the rest of the distributor for damage.

 

Some of the teeth are a little more worn than others. I am just going to replace the whole unit ($80).

So I must have been off, when reinstalling, cause I tried to start and got backfire. Now trying to find proper alignment. Can someone please help???

The book (chilton) says place finger in #1 till compression if felt. (air, right?)

Then continue to turn crank until timing mark is aligned with v-notch. Where is the V-notch (above or below). If it is on above, how can I find it without pulling off all of my accessories (fan and water pump - do not allow line of sight).

Thanks,
Craig