Slight trouble w/ 4.3L V6

bowtie_pasta · December 31, 2002

Just noticed my 97' S10 Blazer (see my avatar) has been a little harder to start. Usually it fires up as soon as I touch the key. Seems now it takes a few more cranks to start. And today it even started and died once, which has never happened!

All the normal tune up stuff is well within maintenance intervals. I don't get any check engines lights at all. I'm starting to think I may need to have the fuel injection system flushed/cleaned. What do you guys think? I heard some discussion about this not too long ago.

Thanks in advance friends!

bowtie_pasta · January 1, 2003

Ok, just spoke w/ my mechanic and he says there is no such flush/cleaning process for the CPI systems. He says since my fuel filter is new that one source could be the Fuel Pressure Regulator. Anyone have any experience w/ this?

later

bowtie_pasta · January 9, 2003

Anyone have any input? I'm taking it in tomorrow, it seems to be getting worse. Stalling at stop lights, and hard starting. Ugggh! Wrong time for this right now! ???

k1500chevy97 · January 9, 2003

On my 97 4.3 it was the fuel pump that was causing those problems you described that was about 2 1/2 yrs ago

CMNTMXR81 · January 9, 2003

This is one of the reasons that GM went away from CPI to SFI in 96 on 4.3's. The "Spider" as the CPI system is nicknamed has a rotating vane that a single fuel injector sprays fuel on. The Vane assembly then distributes it through 6 lines at the end of which is a poppet valve near the intake port of each cylinder. It in effect looked like a spider which is why it was nicknamed such.

What hapeens is that even with good clean gas, these poppet valves would get clogged and therefore affect both idle as well as overall performance. Much the same as a REALLY clogged set of injector(s) would do.

If you can clean it and get it to work again, you're lucky. Otherwise, in 95% of the cases, they simply replace it with a new "Spider" assembly.

However, you have a 97 which is an SFI (Sequential Port Fuel Injected) engine which means there is a single fuel injector at each intake port. So the CPI "spider" problem shouldn't affect you. I'd revert to clogged injectors and/or filter to start. The pump could also be on it's way out which is also a common problem on GM truck.

bowtie_pasta · January 10, 2003

Oh what a day what a day!!! ???

Took it in this morning, received a call late morning. They said they could not duplicate any of the trouble I was reporting. They pressure tested the pressure regulator and all was well within spec. Also they could not pull any codes from the diag.

So I go pick the truck up (free of charge), drive two blocks and it dies on me a couple times. I'm thinking 'wtf!'. So I head over to the gas station to top off w/ some Chevron. On the way it dies a couple more times. I try to start from the gas station and it would not start. Finally got it going and made it home. I called the boys at the shop and tell them what's going on and I decide to bring it back down. However, now it won't start at all. And I can't hear the fuel pump working when I turn the ignition on. So I'm thinking fuel pump for sure (however, previous owner said he changed it once).

But, then we notice when I turn the ignition on none of the instrument panel lights are coming on at all. So I'm getting ready to have it towed and I wanted to roll it out of my garage, but now I can't even move it out of park!! I check the key a couple more times and boom, everything lights up and the fuel pump kicks in and she starts. So off to the shop I go. I get there and it starts doing the same thing. Which is good because now they can troubleshoot better.

They are thinking it may be some type of fuse or ignition switch.

What a day, I was 1 hour late to work!!