I own a 96 GMC Sierra with a 91' 5.7 TPI with very light mods as far as performance goes. I'm having some real cold days in Northern Illinois here. Whenever it gets really cold like this. I have starting problems, I'll turn the key and it usually starts but I have to sit there for 30 seconds and keep it from dieing. I was wondering if anyone else has had this problem in the cold weather. And if so, can you shoot me some friendly advice.thanks Jason

 

what do you consider very mild mods? That may be your problem considering i beleive you have a speed density system.

 

Well it has dome top pistons, a mild comp cam, i think 22lb injectors.

 

ok what are the specs on the camshaft? a camshaft on a speed density system that *is mild* usually doesn't act all that mild to the manifold pressure that you're fuel metering is based off of.

 

Today we can't seem to get it started at all, 30 below wind chill. I just had a friend of mine thats decent with tpi's and he say's it's flooding itself out..but he doesn't know why. We disconnected the fuel pump a few times to burn out any gas. He thinks leaky injectors possibly. Starter fluid seemed to have no affect though, which is just weird in my book. We are gonna try to order new injectors. I'm not sure what my cam specs are, i'm not the best with motors, kinda a laborer. Any other thoughts, thanks for helping so far by the way.

 

Before you order new injectors do a fuel pressure test. Also, check your plugs, wires and cap & rotor.

Jay

 

by the way i found out my cam is a COMP Cams 12-314-4

 

that cam is pretty modest i'm sure drivability wouldn't be 100% with it but, it should run pretty good still.

anyways sounds like your friends may very well be correct about the injectors.

i'd test fuel pressure at the rail (40 bux for a cheapy actron gauge i love mine).

also i'd test the injectors with an an ohm meter (can get 1 of these for 10 or 20).

pull the injector connectors and stick 1 lead to each prong on the injector. Should all read within a couple ohms of each other, i think like 17 is the factory rated injectors. If you find 1 or a couple way out of whack then they are shorted out and you should just go ahead and replace the set. If thats the case go with ford svo injectors.

btw if it truly is flooding itself out try pegging the throttle as you start it, it'll put the computer in clear flood mode. May help enuff to get it started.

G/l i'm fighting my own drivability problems currently so i know where ur at .

 

both of those things have been tested recently and they seem fine, but you think ford svo injectors? 22lbers? And do you happen to know what the fuel preessure should be at or is it kind of a varying all or nothing type thing? Thanx for the helpJason

 

well it shouldn't bleed off fast after engine is off. it varys a tiny bit from year to year but, mine is 43.5lbs with the vaccumm line unhooked from the regulator.

another thing to check is for a rupture fpr diaphram, as soon as you develop fp with the vaccumm line unhooked you'll know if it's torn because, gas will blow out of the hole if it is.

btw yah 22lb hour ford svo injectors or another 1 of my favorites thats cheap and easily available are factory 24lb hour lt1 injectors (they are slightly shorter and bigger). The lt1 injectors don't realy project in to the intake stream much if at all unlike stockers which may help flow the slightest tiny bit + **** loads of them lying around from when they upgrade there lt1s. Although again it is a bit bigger injector which will make it run not 100% optimally down low. So i'd stick to svo's unless your going to get a custom prom tuned for at least the new injector constant.