TBI question

Still working on getting my '91 Geo Tracker up and running. Bought the thing in October, just don't get much time to play with it.

Cliff notes version: Truck has been sitting about 2 years. Spent most of it's life in FL, so it's rust free...and 2WD. When I first got it, tried to start it. It ran for a couple of minutes, then quit. Confirmed it had spark, and the ECU was good. I figured out that the fuel pump had gone bad. I've now dropped the tank, drained the old fuel and replaced the pump.

Fuel is now leaving the tank. It also comes out the other end of the fuel filter (also new), but it still won't start. I took off the intake tube and looked at the TBI, with my wife cranking it. I don't see any fuel being squirted in. If I spray some starter fluid, it fires right up for a few seconds.

Logically, I'm assuming the injector is shot. New ones are expensive. Salvage yards have the entire TBI assembly fairly cheap. I've never messed with these things before. Are they fairly easy to swap out? Anything else I should be looking for before I go down that road?

Hmm, I don't know much about troubleshooting TBI. But could you hook a test light up to the fuel injector to make sure it's receiving a signal? If there's something messed up so it's not telling the injector to open then you would have the same symptoms as you describe. Could be anything from a pinched wire to an ECU. Or it could be the injector.

I'm surprised it's TBI not multi-port. Use a noid light to test the injector. Often you can "rent" them at a parts store. Unplug injector, plug in light. It should flash when you crank it. The injector is likely gummed up from sitting all those years. They are pretty easy to change on most cars. Normally a straight forward bolt-on affair.

TBI assemblies are simple to swap out. Just be sure to get new gaskets, as the old ones will not be re-usable.

Car still uses a distributor? In my experience, 99% of the injetor problems I ever had dealt with fired ignition modules.

Crank trigger might be bad. Don't forget that piece.

Its cake. i can change an injector in about 5 minutes on our TBI 350 chevy. You can take the injector out and crank the motor over. Fuel should just pour out of teh hole that the injector sits in. This would tell you if you have fuel to the injector.

You would definetely see fuel coming out of the injector if it had fuel and was firing.

You can also test all of this out if you have a spare distributor. Plug in distributor into harness and spin teh bottom gear. You can check for spark like this too. It will fire the injectors and the spark plugs. I reccomend checking the injectors this way.

Basically, hook up the spare distributor and unhook all the spark plug wires from the cap. Spin distributor. You should be able to hear the fuel injectors clicking if they are firing. If you don't hear them, they aren't firing.

You must have the key in the run position to do this.

Thanks. I don't have a spare distributor, so that route is out. I'll either get a test light or figure out how to pull the injector and/or throttle body. I'm sure it is pretty easy, just something I've never done before. It does start and run for a few seconds with a quick shot of starter fluid, so it's got spark (I changed the plugs and wires already). I also know the ECU is working properly, so I think I'm good there.

Just trying to make a push to get it running and road safe. My kids constantly ask when I can take them for a ride in it.

Use the distributor thats there then. Just amrk it before you take it out and make sure you put it back exactly where you found it.

pull the injector out and spray the business end with a good blast of carb cleaner.. one of my friends also likes to unstick injectors by hooking the injector up to the battery to jar it loose, but if you do it wrong you can easily fry the injector..