94 Blazer 5.7 Missing and Hesitates when Excellerating

[blazer1994]

Hi All,

I have been having a problem with my 94 Blazer 5.7, Automatic, 205K miles.

No problem starting, but when started first thing in the morn, it idles fine, but once on the road, and I excellerate it hesitates and almost cuts out, no power. Once it warms up, it seems to get better. But has rough idle, and still hesitates on excelleration.

Things Ive done or had done. Replaced plugs (couple of plugs were vry corroded), replaced Air Cleaner, used bottle of injector cleaner.

Took it to the dealer, they put it on the computer and no codes showed up, the first time.

The second time at the dealer, left it over night so they could see the problem when cold. They replaced Dist Cap/rotor, oxygen sensor, and fuel filter. But I am still having the same problem. I am wanted to get a little smarter before going back to dealer again.

Any ideas????????


Help would be most appreciated!!!

[MarkB]

Mine does the exact same thing, Different vehicle but same problem.

I have replaced tons of sensors and checked a number of systems ie. oil pressure. spark ect.

No one knows the reason why this demon is doing what it is doing. It has even gotten to the point of stalling and backfiring. Only in the Mornings though. Or when competly cold. My next check is the PCM or injectors and injector electrical harnesses. Make sure you have no Vacuum leaks first.

Good luck let us know how you make out..

[V-8Fan]

I hate to make the impression that I blame the EGR Valve for everything, BUT!

I would suggest that you disconnect the vacuum hose (and plug it) from the EGR Valve some morning and see what happens. The return spring in the valve gets weak and the valve opens too soon, and you have problems. Give it a try, it costs nothing.