Getting the TBI running again

[Stewzer55]

I'm really starting to get pissed off at this engine.

1988 TBI 350 in a 1 ton with the AIR pump removed and long gone.
This truck used to run and sat for a long time, the injectors died and the throttle body was filthy on the inside.

I cleaned and rebuilt the TB with new injectors. I also had to hook up the ignition module in the distributor and the ignition coil as well, I have not been able to bolt it down because the bolts are missing.

There are a handful of other wires that seemingly go nowhere which have weatherpack connectors on them.

This was my grandfather's truck and I know he wanted to "get rid of that computer **** and put a carburetor and HEI on it"

I need help.

 

[foamypirate]

Post pictures of the connectors and where they are and we should be able to figure it out.

 

[Stewzer55]

Thanks, I'll get some pics of it tomorrow before I go into work, a link to the thread is in my signature and there are pics of the engine in there.

 

[Stewzer55]

I swear I posted these yesterday! I was starting to get pissed that I wasn't getting any help.

Here they are:

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[bucket]

IIRC, that first one with two prongs was for the smog stuff. The one down under the throttle bracket is for the oil sending unit. Then the single weatherpack connector is probably for the O2 sensor, and the single oily plug is probably for the other oil sender (for gauge). I think the one with the large blue wire is something HVAC related? It would help if I was near my truck.

 

[Stewzer55]

Thanks, my oil pressure gauge acts really funny while cranking, it starts at 60 PSI and turns RIGHT. I think my horn is disconnected and I do have a brand new O2 sensor in the cab if that's for the O2.

Now, Where is the oil pressure sender on the back of there? I'm just wondering if I should take the front sheet metal off just to make it easier to get at that. Putting in the distributor module was a huge pain in the ass with the hood on, I can't just sit on the inner fender and do stuff because I'm too much of a fat ass and too tall.

It cranks really well, just no fuel coming from the injectors so I need to check the fuses. with the way the old injectors seized I would not be surprised if the fuses blew under the dash, another thing that's a pain in my ass.

 

[bucket]

If that wire is purple then it's for the O2. You may want to remove the hood, cause one oil sender is next to the dizzy and the other is on the side of the block, near the oil filter area. Does the fuel system prime when you turn on the key? The oil sender with the bigger connector is tied into the fuel pump circuit, but it might not matter if it's plugged in as long as the fuel pump relay is good. I dunno for certain, GM tended to wire them differently through the years.

 

[Stewzer55]

The fuel system primes, if its down by the oil filter would it be better to just get at it from the bottom? I'm wondering if since the ignition coil is not bolted into place if that's causing any issues. What size bolts does that take? Mine have disappeared.

 

[bucket]

The injectors should still fire even if the coil was bad. I think it's held down with 5/16 threaded bolts, about 1/2 to 3/4 inch long. The oil sender is a few inches above the oil filter pad. Getting to it from top or bottom is doable, just personal preference. The one by the dizzy would be MUCH simpler if you have a helper around to get the hood out of the way.

 

[89Suburban]

This is the signal wire for the AC clutch:

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[89Suburban]

This one, to me, looks like the wire that get's unplugged when setting the base ignition timing. Is that wire brown?

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[89Suburban]

1990 TBI Wire Harness Diagram

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[89Suburban]

A.I.R. Harness Diagram - Air Injection Reaction

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[Stewzer55]

Thanks guys, I don't think I'll get a chance to get on this til at least Monday afternoon or Wednesday at the earliest just because I'll be busy with work and other stuff.

 

[bucket]

Thanks guys, I don't think I'll get a chance to get on this til at least Monday afternoon or Wednesday at the earliest just because I'll be busy with work and other stuff.

I just found out I'm going home for a day or two, so tomorrow I'll get to look at my 88's harness and where things are routed. Between that and those diagrams 89S posted, you should be able to have it all figured out soon.