1989 Siverado TPI

[hoogiesngrinderz]

I'm hitting a wall here. I have a 1989 siverado with 98 GMC metal, older 350 crate motor, 6" lift, etc.

I pulled the carb setup off, switched to a TPI with the serpentine setup. I used the harness from my 89 Camaro TPI, 165 ECM, used 22# injectors (off a running motor, so I was told), cold start is there but not wired.

The thing will fire for a second on starting fluid. New Walbro 190 fuel pump, 48 psi while the pump is running and pressure drops to 42 when it shuts off. Bleeds down rather quickly though, faster than I'd like (1 psi/sec). I put a noid light on the injector banks, clip was hooked to positive (constant 12v) and the probe into the left/right bank pin on the ECM. The light is on when the key is off, shuts off with the key on, flashes during cranking. Assuming the ECM grounds the circuit to fire the bank, it should be firing the injectors. Correct? The solid black injector wires do have 12v when the key is on.

I forget what the injectors should ohm out at, on bad one could possibly kill the entire bank I assume. Varnished injectors? I did buy them used for 15 bucks. The chip is an '89 305 AT, cold start isn't hooked up, but that should allow it to at least fire for a few seconds w/o ether...even if VATS were to cut fuel. My dad keeps saying 180 out on the distributor...but I'm almost positive I put the new dizzy in pointing in the same direction.
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[WMCCjames]

If it's only firing for a second on starting fluid you most likely have a timing issue. You should be able to get the engine to run for several seconds and/or continually by using starting fluid alone. Does it pop or backfire when it tries to start? The lack of a cold start injector will make it difficult to start, but not impossible.

With regards to your dizzy.....position is irrelevant as long as the plug wires are routed to the correct cylinder...so check that.

[hoogiesngrinderz]

I'm working on this one solo, so I can stand up front and keep shooting fluid in. The chip is out of my 89, so the cold start is programmed into the chip (89 and up are w/o cold start injector), the intake setup is off an 85 or 86 so I could keep the pre 87 heads that were on the motor.

If the dizzy is 180 out, everything would look right but fire at the end of the exhaust stroke, not compression. I guess I'll pull the valve cover to make sure, gives me a reason to clean things better I was told I might have switched the fuel lines around as the regulator sounds like it is cavitating when the pump runs. I also need to ohm the injectors. What a headache this project has been haha.

[WMCCjames]

Oh, gotcha...I misunderstood your post.

Stock cam? It should be very clear once you pull a valve cover if the dist. is 180 out.

[hoogiesngrinderz]

Oh, gotcha...I misunderstood your post.

Stock cam? It should be very clear once you pull a valve cover if the dist. is 180 out.

Not sure on the cam, I didn't build the motor. It was running (albeit not great) before I pulled the Edelbrock carb setup off and put the TPI on. I didn't have the energy to go out in the garage tonight, flat out exhausted. I guess I should also note that I don't have an o2 hooked up yet, need to swap the headers out to run that. PO cut the collectors and welded the pipes right up...gotta spend some time with the cut off wheel.

The entire truck seems cobbled together, at least electrically. I ripped a bunch of crap out done by the PO and ran only the necessary power wires, still not pretty but crimped connections are better than a bunch of twisted wire with electrical tape! Once I get it running and movable I will spend the time doing it right with a soldered/shrink wrapped/loomed harness (engine, dash, and lights).

[2002Z4CSS]

How did a 1989 truck have a carb on it? I though they were all TPI from the factory. 1987 should have been the last year for a carb. Try pinching off the fuel lines where there is rubber hose and if the pressure dops, then I would say there is an injector stuck open for sure.

[hoogiesngrinderz]

Because someone put one on it??


Truck was built probably 10 years ago, that's the way it was when my brother bought it. It sat for the last few years tucked away in his back yard...I went over and got it running, essentially stole it

I could go back to TBI but I think I'll save that setup on my 85 K5.

[TylerT/AZ28]

they came stock with tbi, most people swap carbs over to them relatively easy, or the tpi setup.
u bought it already lifted and everything?

[hoogiesngrinderz]

My brother bought it the way it sits now, except the TPI stuff, all we did to it was rebuild the trans...twice.

Here is a short vid from my EVO. The pressure bleed off is way too fast. You can hear the cavitating sound a little bit as well. Injectors all measured 16 ohms.

http://www.facebook.com/v/10100551738927682

[98blackbeauty]

You might take injectors out have them cleaned and flow tested. If the truck sat for long and there was gas in it the injectors may be varished up and sticking.

[TylerT/AZ28]

i dont think that would be it. the truck sat with a carb swap he put the tpi unit on so it didnt sit long with the injecotrs in it, although he did say he bought them used

[hoogiesngrinderz]

I have my 19# Bosch III's from the Camaro I can put in, I doubt the truck will ever see the HP to max them out anyway.

[hoogiesngrinderz]

The more I think about this, well, I'm starting to think my old man is right. After work this afternoon I will go 180 on the dizzy.

If it starts, I will kick myself in the nuts

[98blackbeauty]

Normally when you are 180* out you won't start just back fire through the carb or trottle body.

[TylerT/AZ28]

my car wouldnt stat at all when it was 180 out. it would try but then drown out