So I've been having and issue the last three days where my truck would kind of sputter when I slowly acclelerated. Tonight though....I was noticing it quite a bit, and as I was coming home,...and stopped to make a turn...she died! Then I couldn't get her started! Waited about two minutes, and she started up again. Turned and accelerated just fine.....and just before I made it into the parking garage and had to stop......she died again!! This time,....she started right up, but as I pulled into a parking spot, she died again! WTF!! I just finished trying to get her to run again, and she starts fine,....but when you goose it a bit....she goes from 1,000RPM's to 1,500RPM's a few times,....then dies. What's going on here? Thanks for any insight! I can't use this thing until this is fixed or she will leave me stranded halfway between home and work!

 

To start, what are you driving? The year will help us give clear diagnoses applicable to your vehicle. Consider putting that information either in your signature and attaching it to all of your posts or by creating a 'garage' for your vehicle which will put your vehicle information below your username. If you have more than one vehicle in your garage, the vehicle updated last will show so be sure to indicate which one you are talking about when you post.

Depending on the year, you could be a stuck EGR valve, gummed up IAC valve, vacuum leak, or a number of other problems.

 

Sorry......I have a 1995 Chevy Blazer 4WD with 4.3L Vortec

 

All three of the possibilities that I posted could be the source of your problem and would be someplace to start.

EGR cleaning is covered in the tech article section.

The IAC valve is located near the throttle body portion of the upper intake plenum and is easily removed, cleaning both the pintle on the valve as well as the bore it rides in with sensor safe carbon cleaner (same stuff for cleaning the EGR valve).

And vacuum leaks can be checked for by first doing a thorough inspection of all exposed vacuum lines from their source on the intake manifold to the various vacuum powered accessories (EVAP system, HVAC, 4wd, & brake booster).

 

Thanks for the info. I did notice that when I was having the initial problem....it felt like it only did it at a certain throttle position. Now...it just does it anytime you throttle it up and it comes back to idle......or if I just give it just a slight amount of throttle it'll start that "coughing" thing it does before dying out. I was just afraid it was the infamous "spider" or fuel regulator. Just heard it wasn't worth to fix after that. I'll try what you said and report back later.

 

A fuel pressure & leak down test (covered in the Tech article area - the 96+ info is good for the older CPI engines like what you have as well) will let you know if you have a fuel system problem. Typically though, a fuel system problem would show up more at start up. I'm not saying that it couldn't cause your symptoms, but the other things I mentioned are more likely culprits and are easy enough to run through with minimal investment of both time & money.

 

Your symptoms are classic for cracked vacuum tubing or distribution fitting; variable leak depending on engine movement.

When it's that bad you can usually find it by wiggle. To make it a little easier, take the PCM out of the equation by disconnecting the IAC connector - shimming throttle stop if necessary to keep it running.
More difficult issues, use unlit propane along any possible leak areas.

 

Ok......went down to see if there were any codes with the handheld....and nothing. But here's the kicker......She ran just fine!! Let her warm up, and still nothing. And it's cold here in Charlotte today!! WTF? I'm not quite sure where exactly to spray ethyl on there....doesn't seem like too many vacuum tubes running through the top or so of the engine. Any ideas?

 

There are vacuum lines. wiggle them. When a line / fitting is cracked it often lays just right and lets in no or very little air.

And what do you mean 'ethyl'.. I hope you dont mean ETHER. DO NOT SPRAY ETHER!!!!!
Use either a unlit propane torch or a fireplace/grill lighter with flame out.

And check where the fuel lines enter the plenum

 

Ok....here's the word from the mechanic. ASE certified shop says that's it's the CFI AKA the spider. $1000 to pay for the entire job. Signed on a 2004 Z71 Suburban today. Selling the blazer.....first $700 takes away a nice truck minus the spider issue. Thank you all for all the advice....if there is a Suburban Forum.....I'll be there.

Hey Swartlkk......my Suburban is exactly like your Tahoe....same color and all....just a little longer! Any advise on this new truck would be appreciated. Thanks to all again!

PaulDaSilva79@hotmail.com