Getting the TBI running again

[Stewzer55]

No, my small handed assistant wandered off before I got to that.

 

[1911fool]

How did this turn out? One thing I saw in your pictures is the grounds on the T-stat housing. It appears there is only 1 wire there. The TBI's I've had, had two wires grounded there. I would also take this apart and clean it. I've had them do some stupid things because of this ground point.

 

[Stewzer55]

I haven't had much time to mess with it in the last two weeks. I'm not getting a fuel pulse from the injectors after rebuilding the TBI unit.

 

[89Suburban]

I haven't had much time to mess with it in the last two weeks. I'm not getting a fuel pulse from the injectors after rebuilding the TBI unit.

Are you reading voltage at the injectors?

 

[Stewzer55]

I haven't tested that yet, just no fuel spray. I have a couple days off on Monday and Tuesday and I plan on testing more with the truck.

 

[Jhm89]

Hey Stew, I looked at your 88 project thread, and through this post. Just want to say, Congratulations on buying an awesome truck!

I have an 87 350, TH400, 4:10 gears also. So I can safely say, you made a good choice.

That TB looked yucky, You said you tore it down, soaked it, and rebuilt it. When you rebuilt the throttle body, did you put a install a new Fuel pressure regulator on it?

http://www.rockauto.com/getimage/ge...kauto.com/info/SMP/TTRPR131Tphoto primary.jpg

I'd make sure the O-rings on the fuel lines that go into the back of the TB are new or still whole. On your initial tuneup post, right after you bought the truck. I dont see talk of a new fuel filter. I'd throw one at it for sure. Something that might help you get it going once the fuel is being delivered, Put a tiny squirt of trans fluid in each combustion chamber to clean it up a bit, or some seafoam down the TB, but you have to have it running before you can seafoam it.

While your under there, pull the vacc line off the EGR, reach under and push the diaphragm up lightly, cover the tiny vacc port hole with a finger, and let the diaphragm go. It should hold vaccum.

Hope any of this helps. Good Luck man

 

[Stewzer55]

I used a whole kit that came with the new Fuel Pressure Regulator, the O rings were installed on the fuel fittings.

Monday I plan on doing some electrical testing and may get a new fuel filter for it then.

 

[Jhm89]

Even with a clogged fuel filter, I don't think it would cause the spray to stop altogether, unless it was crazy bad. Maybe it's a bad ground, not letting signal get to the injectors. Hopefully you can fire that old bitch up on your days off. If nothing under the hood seems to help, maybe the selector switch under the bed is jacked up. Common weak point from what I've heard.

 

[89Suburban]

Those injectors should always show power with key on. The Computer controls the injector by grounding them.

 

[jeffro308]

Maybe a stupid question but is it possible to have switched the fuel fittings?

 

[Stewzer55]

No, it won't work since they are two different sizes.

 

[Stewzer55]

Small update, Ignition coil is installed, and I'm not getting spark either. I need to bust out the multimeter and see that I am getting power to the injectors and to the coil.

 

[89Suburban]

Ignition module?

 

[Stewzer55]

Could be, I had them test it 5 times in a row so it would be hot and it came back fine. I'm thinking the 12v source could be off or the timing is really far off.

 

[89Suburban]

I wish I was there to help