Cumminsdude

One of my good friends has a 94 Chevy Blazer and he said last night the check engine light came on and by the time he got home it was puddering and felt like it wanted to stall and just wasn't running good. Do you guys have any ideas what this may be? I haven't looked at it yet, but I just wanted to see if any of you guys had some ideas for me to look at. Thanks

MikeyB

Is it a S10 Blazer with the 4.3 or the fullsize with the 5.7? Either way, check the O2 sensor, EGR valve and the fuel pressure regulator.

MikeyB

Cumminsdude

Not sure but I think its an S10 4.3. Anyway, do you have a diagram for this engine so I can figure out where all these things are? Thanks for the help. I'll let you know what i come up with. BTW, Whats the EGR Valve?

MikeyB

The EGR is the exhaust gas reciculation valve. Allows hot exhaust gas to enter the intake for emissions. Not sure about the '94 model but the newer 4.3 EGR is located at the front of the intake on the drivers side.
I don't remember if the '94 has the CPI injection system or just a throttle body injection.
Since the check engine light is on the computer has set a code. Most auto parts store has a reader and they can probably check the code for you. Also, look for any vacuum leaks.

Good luck!

MikeyB

Tiny

I agree with what MikeyB said. I believe the 94s still had a throttle body, so the egr should look like a round sacer on the rear of the throttle body. O2 sensor will be in exhaust pipe, before the catalytic converter. When I look for vacuum leaks, I use a propane torch. Turn on the valve but do not light. You will hear the propane out the nozzle. Take that and go around all of your vacuum lines, TBI base gasket, and the like. When you hear the engine idle smooth out you have found your leak. HTH.

Tiny

MnTom

My nephew had one of those and it started acting up on him too. On his he installed a vacuum gauge on it and every so often no matter what it would go to 0" and die. Turned out some of the hoses wer hosed. He changed all of them and problem solved. I think his was an '84 model though.
Tom

Cumminsdude

How many hoses and I looking at here and how do I know whether they are vacum or something else? Thanks for all the help.

Tiny

If you look on the back of the manifold, there should be a ported vacuum switch. Might have as many as 7 lines on it, as well as lines to the brakes and tranny. Can take a while to trace them all, but as much of a headache as is it is, usually only needs done once. Some of them will be rubber, and others will be the hard plastic.

Cumminsdude

Awesome, sounds great. I'll look at it today and see. Thanks for all your help.