94 blazer 4.3 4x4 starts after a whille??

I have had this truck for about a year and i love it. Never had any problems till now. Since I have owned it i have replaced the plugs, plug wires, air filter and oil filter a few times, pcvalve, fuel filter, belt, fuel pump, battery along with a few other things. I took it about 6 months ago for an emmisions test to get my tags. It failed. Bought new gas cap and took it to a shop to have them test it. Mechanic told me "I hate these trucks the timing is so hard to get right, but this should do it." Still not really sure what he did but i know it was a timing adjustment. He told me to drive it a whille and then have it tested again. So i did and it passed with flying colors. BUT it has been running eraticly since then. After the engine has warmed up I would be going down the highway at about 60 and the revs would shoot up like the engine was cold. Well now it wont start unless i pump on the gas pedal and keep trying. Once started i t runs same as before. Any help here would be much appreciated. Thx Guys!

Sounds like a vacuum leak.

Check all vacuum lines.

thanks lt ill check that in the morning and let you know. i was just going to check cpi but wasnt sure if i pop the cover off to look if ill need a gasket or not?

remove the top IMTV valve if you want to peep down into the plenum quickly.

And yes, if you remove the whole cover you will have to replace the gasket.

You might as well replace the injector and nut kit when you do this so you won't have to replace the gasket again if you indeed have a fuel leak in there.

I checked my vacuum lines and found a couple loose, replaced them. Still hard to start. I have to hold my foot down on the gas for it to start!! A little rough idle and sluggish acceleration. Also i have a tbi system what should i replace if it looks clean(washed) on both sides.

When is the last time you tuned the vehicle up?

About 8 months ago, I think i did everything i was supposed to do. Read first thread and let me know. the only thing im a little currious about is the timing me or the shop could never seem to get this perfect.

Does the engine have the round air filter on the top of the engine, or a plate with VORTEC printed on it.

plate with vortec

Then why did you say you had a TBI system?

You have the CPI system and you CPI injector is probably shot and will need replacing.

Remove the Vortec plate, remove the round IMTV valve underneath it and look down into the plenum and smell for the strong smell of gas and see if there are pools of fuel and washed spots where the normal black deposits have been washed away.

Also smell your oil dipstick for fuel, I can guarantee your oil will be full of gas.

Here is more information:

http://www.s10forum.com/forum/showthread.php?t=113559&highlight=cpi+replacement

i meant cpi sorry you were right. I will check that in the morning and let you know. Should i check my egr also? Thank you very much for all your help! I really appreciate it!

Check the EGR if you want to make sure it is clear of any chunks of carbon.

Well I checked inside that bad boy and it is washed out!! Surprised? I didn't think so. I'm gonna work on it this weekend and ill let you know the results. Also i picked up a gasket and some carb cleaner for my egr. Could you tell me what the symptoms would be if the egr was stuck? Again blazer you have been a big help and have probably saved me hundreds of dollars and for that I am very grateful.

No problem bro, here to help.

The EGR symptons would be hard starting and extremely rough idle.

Replace the nut kit while you are at it. They are the fuel line kit that supplies the injector with fuel. They get brittle as well and should be replaced along with a new plenum gasket.

Well I had some free time this evening and i cleaned out the egr. NASTY. when all back together it idled a lot smother and started easier. gonna do the cpi this weekend i think i had a combination of things going on. I thinki have officially replaced everything!! LOL It's like new!! 140,000 miles. check out gallery for some pics, check out my profile for other vehicles. again thx bro.

remember, replace the nut kit as well while you are doing it, it is worth the money.

BTW, in one of your gallery shots of your engine bay I can't see your PCV valve tube that connects to the intake.

It's there. When you told me about a possible vacuum leak i replaced the two pieces of hose at either end of it. It comes out under the plate. BTW, Last night i pulled the egr and it looked really bad. So i bought a new one, blew out the holes by letting the engine run for 2 seconds, popped it on w/ new gasket and fired it it. No difference at all, not better or worse. I looked in the plenum again and you can see some washing far on the passenger side but not very bad at all after looking at some of the pics of others on here. I was drivin the truck today and it seemed worse than a couple of days ago. could there be somthing else wrong besides the cpi/nut kit? I'm still gonna do the cpi this weekend, jus wondering about a cat converter or somthing.

If you keep on driving it like this, you will have more than a cat to worry about.

That gas is diluting your oil and eating your crank bearings.

Hey Blazer I dont know if youll get this but ive been having some problems finding what i need. what exactly are the parts called and what do i need?

Sorry bro im jus so confused after all the posts iv'e read. Do i need to replace the injector or the regulator, or both or are they the same?????????? ahhhhhhhhh BY THE WAY IT IS A 1993 not 1994 like stated that probably makes a difference, SORRY. Man i feel like a fool

CPI Injector
Nut Kit (Fuel line kit)
Upper plenum gasket

they suggest me getting an inlet and outlet o-ring also is that right? Also do you know whats in the nut kit i keep being told at the store it is part of the injector(spider) assymbly!!

They're idiots then. The nut kit is the inlet/return fuel lines and the o-rings to match. In kit form.

Will it run better for a couple hours if i change the oil. If so im going to go trade it in and take all these parts back. This truck is only worth 2,500 and ive already put 3,000 into it. i think its time to move on.

Will it run better for a couple hours if i change the oil. If so im going to go trade it in and take all these parts back. This truck is only worth 2,500 and ive already put 3,000 into it. i think its time to move on.

Just drive it, no sense trading something that is perfectly fine.

What is the problem is your dumbshit mechanic.

The O-rings came with the nut kit and they also came with the CPI injector as well.

So tell them to install the o-rings themselve because the o-rings came twice.

don't put up with them.