I'd appreciate any insight into this you can give me, and once fixed I'll be sure to post the solution. Here goes:

-1995 S-10 4wd Vortec V6 4.3l with near 99K miles-

The past few months its had a consistent problem starting. It almost always takes between 2 and 5 cranks to get it going. Its gotten no better or worse all this time.

This has now turned to having it stall during idle after its warmed up on the interstate (15+ miles). It will stall at stops when I take my foot off the gas. This can only be avoided if I continue to give it a little gas while breaking, and at rest. If I dont I'll watch the rpm's fall under 700, try to hold on @ 400-700, and finally quit. After stalling, it takes the pedal to the floor flooding trick to get it started again. The trick works like a charm with less than 15 seconds of flooring it for it to work. The idle is also a little rough at all times, but you have to feel for it.

From what I've been reading my first thought is the ICM, followed by the fuel pump/system, then the IAC valve, and on to the vacuum system tubing.

I'll be getting it hooked up to a scanner for the codes tomorrow, and see if the local AZ will also test the ICM a few times to get it warm. I'll report back, but I'd appreciate any first thoughts.

 

First thoughts are either a fuel system problem or a bad TPS sensor.
You can do a fuel pressure test and a leak down test to rule out most fuel delivery problems.

You should be able to find the procedures for testing both the fuel system and the TPS sensor in the tech articles section as well as in your Chilton manual.

 

Im thinking eather a bad injector or a bad temp sensor not the one for the gauge but the one for the computer

 

Mmk here is what the scanner told me... Its throwing me a P1442 code, or "Evap System Purge Valve Blocked Fault". I also remember something about excessive voltage during ignition.

The mechanic told me to get some basic cleaner. He said just about anything designed to remove carbon would do from brake cleaner to carb cleaner. I just needed to get down and clear the blockage from the EGR valve.

Can anybody shed some light on these errors, fill in some details and let me know where to start in fixing this. Also, does this sound like it could be the root of both the problems? (trouble starting, and stalling at idle when warm)

For some reason the ICM and fuel system are still calling to me...

 

Look at this thread. Post #5 has a little info on that code.

 

I have seen this code get set in the past due to the following reasons. It is basically telling you that somewhere there is a vacuum leak or blockage somewhere in the EVAP emissions control system. Or at least the computer thinks there is at any rate.

bad gas cap
damaged, pinched, or blocked EVAP purge line.
malfunctioning EVAP canister purge valve.
disconnected or malfunctioning EVAP vent solenoid.
Open feed circuit to the EVAP vent or purge solenoid. (harness short to the solenoid as mentioned in previous post link)

Your mechanic is right about one thing though. You should get some good intake cleaner and clean up your intake, EGR, idle air control valve. Even if it is not your problem today it will eliminate a lot of common problems for the future.

Though I wouldn't use just anything as he suggests personally since some types of cleaners can damage the electronics in the EGR valve. It is best to use the various cleaners available as they are intended for just that kind of reason.

 

Apparently EGR valves being carbon blocked is very common with this series... Thanks for the link to that post and the advice on cleaners. Time to get dirty and see how it goes from there.

 

A big thanks to garry2000blazer's EGR VALVE CLEANING article
https://blazerforum.com/forum/article-submissions-discussions-47/how-egr-valve-cleaning-discussion-thread-18901/

I got it done on my 95 after removing the air ducting over top the 95's EGR Valve. I've already noticed better performance during acceleration and coming down to idle from speed while in drive.

I dont know if this is going to fix my stalling while warm issue, but it was worthwhile maintenance none the less. My pintle was sticking like mad, I found out, and its now free as a bird after all the sludge I cleaned out of there.

 

I think either the injector cleaner or the EGR Valve clean did the fix on the stall @ idle when warm issue.

I'd still appreciate some insight on the trouble starting. It seems to crank fine, but takes 5-7 cranks when its cold and been left overnight, and 2-4 cranks if its been run w/in the past couple hours. On a rare occasion it might crank on the first go, but if that happens there will be a quick *crunch* noise with it (as though I tried to crank it while running).

 

Don't mean to hijack this thread, I just thought I'd give this topic a bump, as my recently purchased 1998 Blazer 4WD has the exact same issues. For some reason I suspect the vacuum system. Anyway I'm following the thread closely and appreciate any additional replies on the topic.