EDIT: 4.3 V6 Vortec 193HP AWD 1998 model

Hey there,

on my daily I have a problem ( sometimes ).

When stopping @stop lights or construction sides or engine running @neutral while standing, I can see that after 2-3 minutes the engine struggles and stops running.
I can easily restart it, but from then on, I have to play with throttle to keep it running. After driving a few miles, it's okay when standing,... for the next 2-3 minutes.. then the same again.

No DTC saved.
No lamp on
Doesn't matter if good or bad weather.. hot or cold, sunny or rainy

Spark plugs are new, cables are new.

I think it could be a problem with a sensor, or fuel?

What do you think?

Greets

Tobias

 

Had a fuel pump do that...if possible stand by the drivers door and listen for the pump. Should be able to hear it from there. A failing ignition module can do that also. Had one fail similarly then just quit in an intersection.

 

Another area to check is the IACs valve and the throttle body. The IACs (Intake Air Control) valve is how the BCM controls the vehicle's idle speed. If the valve is dirty and sticking it can cause the engine to bog or stall, and it may not throw any DTCs. It's pretty easy to pull the throttle body off (cover the intake plenum while it's off) and clean it really well with brake cleaner and a tooth brush. The IACs is a small module on the side of the throttle body. When you remove and reinstall the IACs from the throttle body, be sure to inspect and possibly replace the O-ring.

It's something you can do that may help (and probably needs to be done anyways), but you're not just randomly throwing parts and money at the truck.

 

Thank you, sounds like a good advice.

 

The ignition module is the one, where the one ignition cable is connected to? On the left side of the motor, when you stand right in front of it?

I have to check everything today. Yesterday, the car broke totally down. On a driveway, upwards, it began to shook, took no gas and did go off. I couldn't restart the engine for at least 35 minutes. Fuel pump okay, at least the big amount of fuel on the ground told me that, when I took of the fuel line of the filter and put ignition on and off. After this time, I could easily restart the engine, but it did not took the gas very well. I could drive it home the 600metres to my girlfriends house.
It will be towed to our workshop today where I can do all the tests.

Any recommendations to start with? Personally, I think it could be a temperature issue?

 

We have seen ignition modules die this way. When cold it fires up right away and can run any length until warm. Once the engine is at operating temperature we have seen stumbles, shutdown or unable to restart when hot. Once cooled down it starts again as if nothing were. No codes, as the ECU sees nothing wrong.

The ICM normally sits on the distributor itself and has two connectors to it. The 1998 should have a three and a four wire flat connector with respective pins on the module.
Would need the 1998 diagnostics to rule that one out.

The ignition coil is located on the rear right of the engine. (All reference left-right is always given in driving direction of the car, as if you were standing behind the car looking forward.)

 

Perfect, thank you. Then I think I have taken all the wrong parts from my second one ( project car ) this morning. I took everything with me, cables, spark plugs, ingition cap, ignition rotator, Fuel Pump, Air Intake with both sensors...

I will change the ICM first ( tomorrow ) and do a longer test drive.

 

Car arrived @ the moment.
Car stood still the whole night, is cold, but doesn't fire up this morning ? Although possible that the ICM is the issue?

 

One step closer to a solution.

It's a fuel problem. ICM is okay, due to that all spark plugs are willing to ignite.

Fuel arrives at the top of the engine, when I remove the cap to take out the air of the fuel system, there is fuel pissing out.
With Pilot Starter Spray, the engine is willing to run.

So, I am not firm to the injection system of my blazer, neither the electric nor the mechanic. Can somebody help out and tell me what to check? I have no electronic plans of the car, and nobody around 100 miles that knows this type of car / engine.

Blazers are kinda uncommon in Germany these days.

Thank you !!!!

 

Maybe someone can make a pic of his engine and name the important sensors, I am not 100% sure, which is which.