CPFI Problem on 4.3 Vortec

If naschco falls through< I have two available

Uhg. 2 hours at pull-a-part finding and remving a spider from a vehicle with a clean and dry plenum, followed by another hour or so at home and the thing runs EXACTLY the same. Barely idles, spits out black smoke and liquid gas. If you rev it, it starts sounding somewhat better, but still rough.

berkeley.

I did do some diagnosing while I was at it though, before I put the plenum back on. With fuel pressure applied but the master injector unplugged, there are no leaks into the plenum. With the injector plugged in and the engine turning over, all 6 of the spider legs are squirting.

Off to FLAPS to pick up tune-up stuff. If I spent all day on this spider BS and a set of plugs fixes it, I'm going to feel dumb.

Cap, rotor, plugs, and wires are in. Holy E36 M3 what a PITA. Reminds me why I like Hondas.

While the old stuff was in need of replacement, that didn't fix the problem. berkeley.

Anybody have any suggestions? What are the failure modes on that spider? I suppose the junkyard one could be bad as well. But what is "bad"? The main lines aren't leaking, and the injectors are pulsing. I suppose the regulator could still be bad, and they are pumping too much fuel. Has anyone been there done that on one of these?

ManofFewWords - Are yours known to be good?

damn. my 95 ran like that and it was just lazy PO who did cap/wires and left in the original 170k mile plugs.

now it runs great, i've got almost 180k on it and i know the spider is a little wonky, it loads up at extended stoplights but clears up when i start driving again.

Did you check for codes in the computer? Stuck open EGR would also make it run like crap.

No check engine light, which is amazing to me, but there you go.

Didn't even consider EGR. Where is it on these?

I know that both of mine are good. I know these things are sensitive in regards to vacuum. Some of the vac lines cook on top of the hot engine. I replaced mine for piece of mind. Let me know if you need one.

I'm pretty sure the EGR is right under the throttle body on the front of the intake. You can try taping on it to see if it frees up and changes how the truck runs. Not too likely but its free and worth a shot.

Cool. I'll clean the EGR tonight. Though I'm not real confident on it being "the fix" it is free and it will be one more possibility checked off the list.

Anyone have any other thoughts?

Hello, I have a 97 Isuzu Hombre with a 4.3 vortec. I have very simular problems with mine. If the truck sits for a few days and I try to start it, it just turns over and over occassionally firing on a cylinder but not starting. Sometimes it takes so long to start that I have to put a charger on the battery to continue trying, which has took upto 3 hrs at one point to get it started. Once started it idles normally but anything above idle is irratic and you cannot maintain an exact rpm. But after 10-15 minutes it smooths out and runs decent but you can still see a very small irratic behavior in the rpm, maybe 50 rpm fluxuation. I have replaced the plugs(gapped .060), air filter, cleaned the MAF sensor very carefully with carb cleaner and a corner of a paper towel, removed and cleaned the EGR(looked fairly clean and moved freely already), Eliminated any vacuum leaks, but nothing yet has fixed the hard to start when cold problem. I read above about a spider assembly possibly causing simular problems, can this be causing my problem? After it is completely warmed up, you can barely tell anything is wrong and only if you use your imagination. But the cold start problem has me stumped, please help!

wtf is with the rash of newly signed up people bringing up 6-12 month old posts with their first post? google to blame?

In reply to patgizz: Its a specific thread and I didnt think another thread needed to be started about the same thing. I'd like to know how you think your post is any more constructive.

aarong81 wrote: In reply to patgizz: Its a specific thread and I didnt think another thread needed to be started about the same thing. I'd like to know how you think your post is any more constructive.

Easy now, his post wasn't calling you an idiot or anything, just questioning why all of the sudden old posts keep coming back from the dead. Reviving old threads isn't that common here. Its a legitimate question: what lead you to the old post?

But sir I have questions, inquires, queries, NEED INPUT!

First, I was replying to a comment only 3 months old. Getting carried away and saying 6-12 months old is purely inaccurate and Im unsure of patgizz's intention of saying that. Second, If patgizz would have said "wtf is with the rash of newly signed up people bringing up 6-12 month old posts with their first post? " outloud instead of typing it, Most ppl would assume he was calling them "an idiot or anything" and at the very least would be insulted by the vulgar cursing. I may very well have been a young child, there is no adult verification to register at grassrootsmotorsports.com which I only have a small sampling of the response generated from the site and hope dearly that not everyone that replies to a legitimate and inquisitive post like mine would respond in such a way. I honostly dont expect anyone at this site to have a mature response relating to the original topic, but more than likely plenty of ppl defending such side tracking, vulgar nonsense. I would however be pleasantly surprised if someone would prove me wrong.

Wow arong-you are looking to be insulted and get angry at people on your first post. That isn't the way to get a warm welcome. Tagging on to an old post isn't the best way to get info here either. Try posting a new post and see if you get a better response. BTW-welcome to the site, I hope your future experience here turns out to be less irritating to you than this one.

I have a 2001 Chevrolet blazer 2wheel drive 4.3 vortec. It has new plugs, wires, cap, and rotor, new crankshaft position sensor and new camshaft position sensor. Also a new lower intake gasket and timing chain. It's done right I know that I did it my self and I'm a mechanic by trade. The stupid vehicle will not start up though, I have not the slightest idea of what it could be. I haven't checked fuel pressure yet to see if it's the spider. Does anyone have any idea

patgizz wrote: wtf is with the rash of newly signed up people bringing up 6-12 month old posts with their first post? google to blame?

+1

patgizz wrote: wtf is with the rash of newly signed up people bringing up 6-12 month old posts with their first post? google to blame?

Because on many automotive type forums making a new post about any subject that has been discussed in the last year will get you the same treatment or worse than what some of you are exhibiting.

Hal wrote:

patgizz wrote: wtf is with the rash of newly signed up people bringing up 6-12 month old posts with their first post? google to blame?

Because on many automotive type forums making a new post about any subject that has been discussed in the last year will get you the same treatment or worse than what some of you are exhibiting.

1. 5 year old zombie thread, brought back up this time by someone asking about a totally different intake system with what may or may not be a similar issue, that dave had with his long gone bravada that i still think i should have bought.

i was not married when this thread originated, now i have a son turning 3 and another on the way.

i still blame google, 5 years later.

and yet nobody has produced the man on man action.

In reply to patgizz:

You blame google for the birth of your child?

gofastbobby wrote: In reply to patgizz: You blame google for the birth of your child?

no, but i do credit the internet for me not having any children before i hit 30.