1999 4wd 4dr.

History of hard start that are worse in the cold or long periods of down time. 8hrs or less it generally starts right up. No driveability issues. 55-60psi FP. FPR changed last spring.

So...I replaced ALL the o-rings in the spider that you can get to without cracking the case. I cleaned stuff up as well as took pictures before I started. I'll try to get those up in a day or two.

I hoped the FPR was leaking. No evidence of it.

#5 port was clean as a whistle. I don't think it could have been cleaner if I bead-blasted it. Back when I changed the FPR the #6 port showed signs of wash.

As I was disassembling things I noted the bottom of the spider was relatively clean too. The kit I got was a Dorman part number 90000 which had all the rings, retainers, plate, etc. Some of the o-rings looked a little tired.

After going through everything I reinstalled the spider and fuel lines without the Upper intake. Leak check w/ key on and crank (inj harness plugged in. No leak.

then I put on the upper and made all the connections, but did NOT mount the TB so I could see inside. Again - key on and crank. No leaks. Wish I'd done that before I started.

The result = well, now I've done it and it does run smoother.....it did seem to help the hard start after sitting long, but it still requires 2-3 attempts to get it running.

At this point I think I'm going to suspect the fuel pump isn't putting out the necessary volume. Quantifying that would be difficult and, to me, not worth the extra trouble. Pressure is good and driveability seems fine, but it does seem to lack top-end (for this motor). Testing FP during this does not show pressure dropping at upper RPMs though. I don't suspect the spider further unless someone else can show me cause.

Thats all.....

Happy motoring.

 

What motivated you to work on the spider? You said it wasn't leaking???

I'd bet your fuel pump is fine... the top end shortage is more likely an oxygen shortage if anything.

How's your battery? Older than a year or so and it might not put out quite enough cranking amps after sitting for more than a few hours. I swore the battery was not my problem until it sat for a month and would hardly crank at all. A new battery fires up that truck almost instantly, every time.

on the other hand, the 97 blazer I just got doesn't fire up like I'd expect it to with it's new battery + cap&rotor. I hope to find a reason why next week when I pull everything apart for intake manifold gasket replacement.

 

Your fuel pressure is right on the money. At the upper RPMs you're putting out the same psi. That should tell you that your pump and FPR are working fine. Sounds like you don't have a problem with fuel. By the way do you have a fuel pump prime port? It'll run the pump without cranking the engine and is great for leak checking and checking fuel pressure with the upper manifold still removed. On my 94 it's a Gray wire coming out of the wire loom on the right side of the firewall pretty close to the junction block. There is a female connector on it that doesn't attach to anything. You're supposed to use a fused jumper and I just run it straight from the battery. An in-line fuse (with 15 amp fuse) and an extensio with a blade terminal works just great. I'm surprised so many guys don't know about this. It sure is handy.