Tbi help!

[sntrym]

Ok cool. A few other thoughts then.

How is the oil? Any metal or other bad stuff?
What color are the fuel injector lines? I saw the chart posted before but didn't see a response on that.
It would be best to get the ALDL cable and TunerPro to see what the sensors are showing and the ECM is reading.

 

[sntrym]

Also, what ECM do you have? There should be a number on it and 4 letter code.

 

[Dak24]

Well I think we got it fixed finally.

I found someone locally who knows more about the tbi systems come look at it, he said that a lot of the failures he saw were the ignition control module in the distributor and he said to replace it. I found a new distributor for just a little bit more than just a control module and put that in instead.

Now it runs much much better, it's still not the smoothest motor ever but it doesn't hesitate like it did before and you can actually get some decent power out of it. It still has a split second hesitation if you rev it up fast under load, is that just normal? In any case it's certainly useable now.

Now that it actually runs good enough we decided to put the bed on it, what a relief.

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[Schurkey]

A "new" distributor that costs not a lot more than "just" an ignition module is almost certainly a bottom-feeder Chinese unit.

Good luck with that module.

The remaining problems are NOT normal. There's still something wrong.

 

[1989GMCSIERRA]

I wonder if the sock in the fuel tank is clogged up?

what about the fuel injector screens?

can you put a pressure gauge on the fuel line to see what your PSI range is when you’re revving up? It sounds like a fuel issue to me. Somewhere something is preventing enough fuel from getting to the engine.

you can use a timing light to check the spray pattern on the injectors.

 

[Dak24]

I wonder if the sock in the fuel tank is clogged up?

what about the fuel injector screens?

can you put a pressure gauge on the fuel line to see what your PSI range is when you’re revving up? It sounds like a fuel issue to me. Somewhere something is preventing enough fuel from getting to the engine.

you can use a timing light to check the spray pattern on the injectors.

I had a pressure gauge on it recently and the pressure seemed very consistent, however that's not to say that it would be now, if I get a chance I'll have to put my guage on when I'm using the truck and see what it does.

Never heard of using a timing light to check the injectors how do you do that?

Oh by the way the injectors screens are clean, and the truck has a new fuel filter, I haven't been able to take the pumps out to check on the fuel socks

 

[Dak24]

A "new" distributor that costs not a lot more than "just" an ignition module is almost certainly a bottom-feeder Chinese unit.

Good luck with that module.

The remaining problems are NOT normal. There's still something wrong.

Yeah I'm sure the distributor isn't very good, but it's what I could get locally, hopefully it lasts ok at least for this year, this truck probably won't get more than 500 miles on it a year so hopefully that cheap distributor will last. I may order a better one from rock auto to put in when I get the time

 

[1989GMCSIERRA]

I had a pressure gauge on it recently and the pressure seemed very consistent, however that's not to say that it would be now, if I get a chance I'll have to put my guage on when I'm using the truck and see what it does.

Never heard of using a timing light to check the injectors how do you do that?

Oh by the way the injectors screens are clean, and the truck has a new fuel filter, I haven't been able to take the pumps out to check on the fuel socks

put the timing light on the vehicle as you would if you were checking the timing. Instead of aiming the gun at the crank pulley as you would to do the timing Aim the gun at the injector tip. You’ll see the spray cone pattern better as the timing light will strobe and give you a better look at the spray pattern.
I also found this.


http://www.73-87chevytrucks.com/techinfo/TroubleshootingTBISystems.pdf

 

[PlayingWithTBI]

You can use a flashlight too. Shine it on the back of the bore and you can see the spray cone. Look for drips too. If you see any, it's time to rebuild the throttle body, you may have a pinched O-ring (hopefully) or a bad injector.

 

[Batman]

Greetings:

Hi all, new to the forum, looking for any info that would be beneficial on these tbi systems.

I have a 93 chevy kodiak with the 366 gasser in it and I'm really having a hard time getting it to run right. I know this site is for the gmt 400s but I was hoping someone on here could just share any information.

The truck starts good, but seems like it runs really poorly to me, and as it warms up it seems like it gets worse. I run it up and down the road a couple times and it can't really even get out of it's own way. it seems like it has a miss that's inconsistent as well.
I've replaced: iac, map sensor, injectors, fuel pressure diaphragm, plugs, wires, cap (haven't been able to get a rotor yet), coil, coolant temp sender on the intake manifold, oxygen sensor.

Tested: fuel pressure 20 psi (my gauge works to 100psi if that matters)
Tps: .55v at idle, 4.44v at wot
Codes: only showed code 12

I had a friend look at it and he messed with the timing when it was running but that didn't help much, I tried spraying around the intake manifold with starting fluid to see if it had a leak but it didn't seem to, I checked the vac lines on the engine when I replaced the sensors and no leaks, I checked the egr and it works like it's supposed to, cold compression is between 135-150.

Any suggestions? I am really confused on this an I've already thrown a lot of parts at it.