SCFI == Sequential Central Fuel Injection

It is what the '96-mid'02 4.3L has for a fuel injection system. It describes the injection spider with its centrally located injector pack housing 6 injectors in a common housing. Each injector feeds fuel through tubes down to pressure actuated poppet nozzles in the intake runners directly ahead of the intake valve in the cylinder head.

CPI == Central Port Injection

This is what the '92-'95 motors had for fuel injection. Same spider arrangement with a single central injector feeding 6 individual pressure actuated poppet nozzles at each intake port.

The newer mid'02-current motors have an MFI (multiport fuel injection) spider which moved the electronic injectors out to the intake ports removing the somewhat problematic poppet nozzles from the equation. This injection spider is a direct replacement for the '96-mid'02 SCFI spider.

As far as your problem, I still would be curious as to how the voltage at the pump is reacting. Too low of voltage can cause this same scenario. Could be something as simple as a corroded connector...

 

i already checked the connectors there fine

 

well i think that the fuel pump is most likely answer so im going with tat

 

Yes I would go with the pump so replace that and let us know the results we like when people repair something and come back to let us know the outcome!!!

 

Well installed the fuel and it runs and the pressure hold and when i turn the key it kicks right up to 60 lbs instead of 40 ilbs but, its running rough and the check engine light is blinking

 

Have the code read, but I'll bet it's a P0300 (misfire).

 

My '96 is having a similar issueas Ridinblazer's. I plan to replace the filter and WAS going to also replace the fuel pressure regulator -- but after reading all these posts, I think it would be smarter to get a fuel pressure gauge first, then while replacing the filter, determine conclusively whether the problem is coming from the FPR or the fuel pump prior to performing any more repairs.

I've noticed that it is gradually taking more and more attempts before the engine starts, so I'm a little worried that if I don't take care of it soon, it won't start at all.

One thing Kyle pointed out that concerns me is the fuel pump voltage. Is there any way to test this, seeing as the pump is inside the frickin' tank? And even if you can test it, doesn't that still mean you'd have to get the thing out before you could repair it (meaning you might as well replace it at that point)?

Last (Ridinblazer), I think it is REALLY weird that you suddenly got a misfire code after replacing the fuel pump. Could this mean that the new pump is now pushing too much fuel? (It seems like the more you learn, the more confusing it gets.)

 

Well it didnt get a misfire code right away it kinda ran rough b4 but i didnt bother with n e thing... once i replaced the fuel pump i also did a tune up i replaced cap rotor and wires no plugs .... and it ran ok after but still had the usuall mis to it and then within the next xouple days it just got worse so i decided to check out the plugs and they where junk so i replaced all but the one by the intermiate shaft for now and its running like a dream i am going to by a swivel to get at that one or take the shaftout.. but thats what my problem was

 

Very good, I hope that wraps it up for you.

 

Yeah, Ridin...glad to see your ride is A-OK now. I still haven't done anything with mine, because the weather hasn't been on my side. There's been near-constant rain and ice during the past week, and I don't have a garage. However, the weather just got nicer today and is supposed to hit the 50s tomorrow, so I plan to do the fuel filter replacement this weekend.

I noticed thatthere is a box-like structure just underneath the left bumper end. I suspect the filter is under there, although I may decide to inspect the length of the fuel line first before opening it up. I'm assuming this is something they stopped doing after '97, because my Haynes manual didn't show anything like that. I also decided that I won't get a gauge unless replacing the filter doesn't resolve the problem, because then it would be cost-effective to buy the gauge and determine immediately whether it is the regulator or the pump that is the culprit. Meanwhile I've been shopping around for pumps, so that I'll be ready to buy one if I need it.

Has anybody seen this aluminum fuel pump before? They claim that it is a direct replacement that works better than stock. I noticed there were a few negative customer reviews, but note that their vehicles appear to be the wrong ones. One '96 Blazer owner gave it good reviews.