72Short

I have a 5.3L out of a ssr. It is getting gas, It is getting spark. It is cranking over but will not start. PCM was reprogrammed and vats dissabled. Anyone?

Thanks in advance.
Jeremy

DaleMX

iTrader: (4)

Coil packs upside down? (easy to do and happens quiet often) Does it pop? Have you tried keeping the pedal to the floor while cranking?

01PewterWS6

Just for starters go thru make sure everything is hooked up and check grounds for the harness, you still have the data port? maybe hook a scanner up to it and see if its throwing any codes...

custom 68

iTrader: (9)

make sure on the fuel side that you are getting fuel out of the injector. Mine had sat long enough that the injectors were stuck shut. There was fuel pressure and a pulse but they were not opening, I pulled my rail to find this. With sombody trying to start this (coil packs unpluged) and only one injector plugged in I tapped on it till it shot fuel and did this on all 8 once back together it fired right up. Mine was a 2002 that had sat for 2 years.
I am pretty sure if it has spark and fuel it should start...
good luck
Dave

SprayJ

iTrader: (17)

If you are getting gas and spark and the ECM is burned it should start. A few things to check...
1. Make sure you have an injector pulse and a pulse to your coils, not just a hot signal because your injectors and coils pulse on a ground source. If not, check your crank sensor wires coming into the ECm and make sure you have a pulse on the yellow and black wire. Your pink wire should show a + signal, make sure you have a pulse though.
2. Make sure the connection into your ECM is good and tight...even if it is, shake the connection a little while someone else cranks...Ive had a few connector pins work themselves loose on the red and blue plugs into the ECM
3. What is your fuel pressure at? Make sure you have fuel pressure in your fuel rails as well.

Let me know if you get it started...my 60 Impala gave me a few headaches in the beginning as well but she's rolling down the road now!

jimmyp

iTrader: (1)

yeah make sure your injectors are actually injecting...my problem for the longest time was that I didnt have the correct psi at the rails

72Short

I havent had a chance to get to my truck, but I am using a blazer gas tank and an aeromitive a1000 fuel pump. I was told that the truck manifold has a fuel pressure regulator built into it. So I do not have a regulator. I guess I need to get something to make sure that it is pulsing. I will also double check all the grounds.

I do have one more question. I have a wire, not sure if it is a ground or power wire up by the throttle body, alternator area. Is that one a ground or power. I am assuming power, without having it hooked to power, I didn't have any power to the ignition system.

Thanks Jeremy

Maybe I can get to my truck tomorrow

custom 68

iTrader: (9)

What wiring harness are you using. I used a Painless for mine and it had a grey wire up there also and it was the "exciter" wire for the alternator, but it was labled and in the instructions on what to do with it. You may want to check to see what it is.
good luck
Dave

jimmyp

iTrader: (1)

you can buy a gauge or do like i did to be sure....lift the whole fuel rails assy an inch above the manifold just to be sure there is fuel coming out

72Short

well I got to work on my Truck today. I fixed a f uel leak that was at the pump. I also pulled the fuel rails and checked the injectors, no fuel. I dont Know how to check to see if they are pulsing. I also made a small movie if someone Can post it.

Formulized94

iTrader: (68)

194 light bulb is the easiest to check injector pulse. i am having the same problem with my 5.3 today. i am assuming it is the fuel injectors clogged

jimmyp

iTrader: (1)

from what I understand if you dont have exactly 58 psi at the injectors they wont provide fuel. So either your pump isnt providing at least 58psi or you need a new fuel regulator, which I believe is still on the fuel rails with the truck intakes. You can buy a fuel pressure gauge on ebay for $34 that installs on the fuel rail...might help
good luck, believe me it will all be worth it when it fires for the first time!!

Formulized94

iTrader: (68)

i dont think haveing or not having exactly 58 psi, is gonna keep it from running. Mine has 55 to the rail, which i think will work fine when the injectors are cleaned

72Short

Which guage are you talking about? There are many on ebay. It would be nice to have to see if I have enough pressure. I should, because I am running an Aeromotive A1000 fuel pump.

G-Body

iTrader: (4)

You do not need exactly 58psi for the injectors to fire. My 5.3L will run on as low as 20psi, not well, but good enough to get home when you crack the fuel line between the pump and sending unit. Don`t ask how I know. I bought my fuel press gauge at auto zone, it is an Actron PN CP7818 I think it was around $40.

jimmyp

iTrader: (1)

i could be wrong but when I was battling my initial engine startup and that was what everyone said was my problem...and it was. Just going off what I was told.

jimmyp

iTrader: (1)

here is the one I got
http://cgi.ebay.com/ebaymotors/GM-10...10229415QQrdZ1

72Short

Had a chance to test the truck today. It has pulse at the injectures. What is the largest size injecture that I can use? I am looking either at NOS 30lb or accel 26lb. I really don't want to reprogram my computer again. I am also using a BBK 80mm throttle body and an aftermarket MAF if that helps. Thank so far for the help.

Ryan72

Hey wait a minute guys, the truck manifolds have a regulator built in to the fuel rails?? no return line?? I have an LQ9 6.0L. I don't need to run a corvette filter/regulator? Will it still work if i put one before the fuel rails anyway??

Sorry for the hijack. thanks for any answers to my questions!!!

crainholio

iTrader: (2)

I agree that checking fuel pressure is a good troubleshooting step, but the statement above is incorrect. Confusing the guy with incorrect data while he's troubleshooting is not cool.