94 s10 blazer 4.3 vortech starting prob. please help!

[ky686]

ok im new here but here is the problem . i have a 94 s10 blazer with the 4.3L vortech cpi vin.w . the truck was running great and then the next day it would turn over but not start. after trying for about 10 min. it finally started i drove it around and it ran good. i parked it and shut it off and started it a couple more times and it did fine. it sat for about 2 hours and would not start back up i replaced the coil, cap and rotor, and fuel filter it ran and i drove it to work were it sat for about 5 hours i went out and it started fine i moved it and when i shut it off it would not start again. it was towed home and i had the ignition control module checked and it was good. i found out that if you put gas in the throttle body it would start but only run long enough to burn that gas so i replaced the fuel pump. i still have the same problem it turns over but wont fire. where do i go from here any help would be greatly appricated thanks

ky

[Gabe25]

First of all, Welcome. What is your fuel pressure reading ? It should be around 60 to 65 psi with the key in the on position. Then in the off position, your pressure should hold for a couple of minutes and shouldn't go lower then 55 psi.

[ky686]

i couldnt find a pressure gauge that would work on it thats why i went a head and put a new fuel pump in since it started when there was gas in the throttle body

[MT-2500]

Some parts store loan or rent or sell fuel pressure gauges.
Get one and make sure you have good fuel pressure.
If no start and good fuel pressure check for injector pulse.
Check for injector pulse to intake.
If injector pulse there pull cpi cover and check wiring and for injector pulse to cpi unit.
I have had some with broken or lose wiring from outer intake to cpi unit.
MT
MT

[ky686]

well i cant find a fuel pressure gauge in this town that will fit but i took the vortec cover off and removed the tuning valve and when looking down the hole it seems to be pretty wet towards the drivers side an not very wet on the passenger side. could this be from simply pouring the gas down the throttle body to start the truck? or where do i go from here?

[MT-2500]

Originally Posted by ky686

well i cant find a fuel pressure gauge in this town that will fit but i took the vortec cover off and removed the tuning valve and when looking down the hole it seems to be pretty wet towards the drivers side an not very wet on the passenger side. could this be from simply pouring the gas down the throttle body to start the truck? or where do i go from here?

No.
If it is wet or shinny there is a fuel leak in there.
Disable dist/ign spark and hook the fuel lines up and prime up fuel pressure and watch for leaks on the spider and fuel pressure regulator.

If no one has a fuel pressure gauge you need to order one.
You have to have one to test/check it out.
MT

[Gabe25]

Originally Posted by ky686

well i cant find a fuel pressure gauge in this town that will fit but i took the vortec cover off and removed the tuning valve and when looking down the hole it seems to be pretty wet towards the drivers side an not very wet on the passenger side. could this be from simply pouring the gas down the throttle body to start the truck? or where do i go from here?

MT is correct. You need a fuel pressure gauge to work with. On your fuel injector spider. the fuel regulator is located on the Passenger side in the plenum. You said that the driver side seems to be wet. I would say that your nut kit is probably leaking. If you remove the upper plenum then do what MT, had said about Disable dist/ign spark and hook the fuel lines up and prime up fuel pressure and watch for leaks on the spider and fuel pressure regulator.
You'll find where its leaking from. Here is a link that will show you how and what to look for. http://www.automotiveforums.com/vbul...d.php?t=473110 . Keep us posted.

[ky686]

ok it is now running and i want to thank you mt and gabe for all the help. after i replaced that fuel pump i took the intake apart and cleaned it up i couldnt find the leak and went ahead and replaced the fuel pressure regulator and the gasket and put it all back togeather. it still would not fire unless you put gas down the throttle body as before. i went to auto zone and found a fuel pressure gauge they had just got in. i was talking with the guy there to make sure it would fit and we got to looking at the pressures for the fuel pumps on their computer he brought up the warrnty information on the pump i had bought and it turned out that the guy had sold me the wrong pump he sold me the one for the tbi instead of the cpi so i told him to hold on to the gauge for me and if the new pump didn't work i would come back and get it. well needless to say i didn't go back and get it because the right fuel pump solved the problem when i got it in she fired right up. i feel kinda stupid since it was just that but hey its a learning experience right? ha ha well thanks again guys for all the help

[MT-2500]

You are welcome and thanks for posting back how it went.
Glad you got it figured out and all is well.
Good luck
MT