95 k1500 no injector spray

sorcerer86 · October 09, 2011, 07:16:21 PM

So last year I moved my truck. Ran about 10 minutes. After I shut it off a few days later it wouldn't start. No power to anything. Like dead battery. Didn't want to mess with it. So a year later and I decided to try and get it running yesterday and here is where I'm at. I got battery power again. It had badly corroded ground and power connections was all it was. But now no injector spray.
I replaced fuel filter, and checked I get fuel up to the tbi. I got the noid test kit and when I roll over engine it flashes just fine. I also had the icm tested and it was good. I can spray starting fluid in and it starts just fine. But no injector spray.
Could the injectors be plugged, or some other part of the tbi assembly? I'm at a loss as to what to try next. I didn't check fuel pressure, but it gets fuel to tbi.
Thanks, mark.

dietsch · October 09, 2011, 11:33:16 PM

Check the fuel pressure with at gauge them injectors need x amount of fuel pressure to open I don't remember the spec right off hand but I had ran into the problem before.

sorcerer86 · October 10, 2011, 09:56:21 AM

OK. So the pressure does matter for the injectors to spray. I'll check that. Thanks.

Disturban · October 10, 2011, 03:52:17 PM

Quote from: sorcerer86 on October 10, 2011, 09:56:21 AM
OK. So the pressure does matter for the injectors to spray. I'll check that. Thanks.

Should be between 12 and 15psi preferably 14-15ish, is the ecm sending a signal to the injectors?

sorcerer86 · October 11, 2011, 11:54:56 AM

The fuel pressure when I turn the key on goes to around 20 then slowly bleeds off to around 14-15 and holds for a long time. As far as ecm signal isn't that what the noid test light does. I plug it in to the 2 injector harness spots and it flashes when rolling over.

Disturban · October 11, 2011, 03:57:52 PM

Quote from: sorcerer86 on October 11, 2011, 11:54:56 AM
The fuel pressure when I turn the key on goes to around 20 then slowly bleeds off to around 14-15 and holds for a long time. As far as ecm signal isn't that what the noid test light does. I plug it in to the 2 injector harness spots and it flashes when rolling over.

Yes if it is flashing the injectors are getting a signal, I find it hard to believe that both injector went bad at the same time, I suspect you may have one bad injector and that would keep it from starting, hold your finger under each injector while having someone crank it over and see if one or both are not spraying. Even if they are spraying it needs to be a nice cone shape spray pattern, you can hook up a timing light and point it in the injector spray and see it very clearly. Hit a local pick and pull and get some new injectors and give them a try.

dietsch · October 11, 2011, 06:01:54 PM

does the tac move when cranking?

73chevytruck · October 11, 2011, 06:06:46 PM

Check your fuses. Theres a fuse that will say injectors a+b. For some reason my fuse blew when my truck sat for a while and i replaced it and it fired right up

sorcerer86 · October 13, 2011, 11:46:16 AM

First thing I did was checked fuses, they were all good. But my problem isn't getting power to the injectors, I tested the injectors with the noid test kit and it flashed telling me the injectors are getting power to spray, just nothing comes out.
I'll try some new injectors when I get a few bucks I guess......
do u know a good tutorial on getting them out. The autozone website says they just pull/pop out, but I looked and it seems I have to take 7-8 screws out and pop the case holding them in half first. But I don't wanna break anything.

And as far as the tach moving, hmmmmmm Im not sure. I can check when I get home. If its not what would that mean?