Is there something better than the OEM TBI carb for my '95

[94burbk1500]

Could you educate me on that system and set-up?

Would that be one of those Fitech's ?

Holley and Fitech are probably the most common ones, Haltech might offer something too. Essentially you get a kit that replaces the fuel system and ECM, the new ECM has a standard tune that probably runs really rich, just to get you moving, then as you drive it learns the engine better and adjusts the fuel rates on its own. I'm not an expert, I'm paraphrasing, and i'm probably getting some of that wrong, but that's the gist of it. They are really cool, but they aren't cheap.

 

[the4300guy]

If you want a new efi system, mega squirt, holley, msd atomic efi, fitech etc. But you're running super rich. Unplug your tps and see if it starts easier. Also unplug your map sensor and try it. Do one then the other. If it all of the sudden starts then check the voltage on each. That's the easy way to check. But if you have stupid issues like me(20 psi of fuel pressure) then you need to adjust your fuel pressure reg or retune.

 

[tdc917]

The TBI, albeit unsexy, is an incredibly reliable fuel injection system. I suspect your issues are elsewhere. Are your plugs, wires all good? Any fouling?Have you triple checked your firing order and wire location? I’d also try an OEM coil, they’re cheap on eBay or Amazon. Those street fire coils are garbage in my experience, the Accel ones are even worse. I’d also verify timing, though you said you’ve done that. Valve adjustment could also cause these issues.

You could go aftermarket EFI or put a carb on it, but IMO not worth the cost at all in your application.

 

[Rodney Saunders]

Sounds like a timing/ fire issue to me ...

 

[Knuckle Dragger]

The TBI doesn't have an accelerator pump (the AE TPS PW table does this in your bin file) so, pumping it before starting doesn't do any good. When you turn on the key the fuel pump will run for about 4 seconds. If you cycle the key off/on it'll run another 4 seconds. If that helps starting you have a pump or filter problem.

Did you set up the TBI initially?

http://www.gmcmidwestclassics.org/Web pages/Tuning the TBI.pdf

^^^^^^What he said. Before you start throwing a bunch of parts in it relax on the starting it ritual. You should push the gas to the floor once to set the "cold start" and then don't touch it again. If you're going over 3/4 throttle while cranking you'll put it in "clear flood" mode and starve it. Try and start it my way and see what it does. If no start, cycle the key as suggested above. If that doesn't get it to fire scan data, scan data, scan data. Quality parts are too expensive to be swapping out on a whim. Let's see what the ECM sees and pinpoint where we need to go from there.

If you had TBI deficiency issues they would show up on the top end not start up.

 

[Schurkey]

"push the gas to the floor once to set the "cold start" " - Is this a thing?

Not that I know of. My truck starts at -20F without it.

I haven't heard about this.

Me neither--until now.

 

[Knuckle Dragger]

"push the gas to the floor once to set the "cold start" " - Is this a thing? I haven't heard about this.

Part of the GM programing since they rolled out fuel injection. It's just like setting the choke on a carb. I "heard" about it in GM tech school.

 

[DerekTheGreat]

Huh.. I've never heard that. What does it do differently? Like Schurkey said, my truck fires right up with the twist of a key. It'll idle at 1000, 1100 or 1300 RPM depending on how cold it is when it fires.

Now with my old '85 LTD Crown Victoria, that was indeed a thing. It had a rather primitive TBI set up that Ford called CFI. Ford's throttle body shared similarities with GM's unit yet lacked an IAC motor. It used an electric choke-pull off mechanism and a vacuum dashpot to adjust idle. With that thing, you did indeed have to press the gas to the floor like with a carb to set the fast idle (provided it was even adjusted correctly) otherwise it wouldn't run. I don't think the Ford enriched the fuel mixture like GM did. Fast/cold idle speed was 2100RPM or something absurd like that. I set mine to about 1800.. You'd think I'd end up hating Ford CFI, but I actually have a soft spot for it...

 

[Knuckle Dragger]

This isn't a mechanical deal. The way it was explained to me was key on, one push to the floor on the accelerator signals the ECM that it's a cold start. The ECM uses the coolant temp sensor to confirm it's a cold start and shifts the tables to accommodate the cold start. I took this class from GM in about 1986 a an apprentice in a GM dealer. It was of great importance to me because the frickin lot porters were running down batteries and fouling plugs jacking around to fire them up in the morning. I was the poor ******* tasked with getting them running out in the lot. I cannot find anything on the internet that goes into it at all or I would post a link.

 

[Schurkey]

So far as I know...the computer looks at the coolant sensor at key-on and knows it's cold. No need to push the pedal.

I suppose now I'm gonna have to look at the owner's manual for my '88 K1500 for cold-start instructions.