88 k1500 350TBI I'm puzzled!!!

Chevy350guy · 10-30-2009, 12:16 AM

I have this 88 chevy truck with 350 TBI and it was driving fine one minute. Then I stop to fill it up with 91 octane from chevron and even tossed in some fuel injector cleaning crap. But when I started the truck it would surge at idle then stall out but if I stayed on the gas it would have a little power but seem to starve for fuel. It has new IAC,EGR,fuel pump, fuel filter. The injectors aré spraying solid but not enough. Fuel pressure from the fumo after the filter is at 14 lbs. Please help I am lost as well as everyone else I know. One guy told me to replace the whole TBI unit

inafogg · 10-30-2009, 12:45 AM

so if you spray carb cleaner in tbi it regains rpm's???

Chevy350guy · 10-30-2009, 07:57 AM

Yes the carb spray does help. Do you think it could just be the TPS?

Chevy350guy · 10-30-2009, 04:55 PM

Would appreciate any info from anyone I am put of work due to this problem. I just don't want to replace the whole tbi if it could be a cheaper route to go

manicmechanix · 10-30-2009, 05:23 PM

It sounds like your fuel pressure is good, but the fuel injectors arent' delivering enough fuel. You might try to check their resistance with a voltmeter. I think you can replace the injectosr separately without replacing the whole TBI.

You could try putting a big bottle of Techron and running it to see if it helps any. Chevron is good gas, but sometimes you get bad gas from a station. More likely the injectors are just bad.

Chevy350guy · 10-30-2009, 05:43 PM

They looked like they were spraying fine but I'll check it. What is the voltage to check?

777stickman · 10-30-2009, 07:21 PM

From your 1st post I would suspect a bad batch of gas. If it's water it sinks right to the bottom where the pickup is. Or it could have been what ever injection cleaner you put in? There may be some kind of product you can put in the tank to remove water at your local parts store. I wouldn't start replacing parts until this is checked out.

manicmechanix · 10-30-2009, 07:41 PM

Quote:

Originally Posted by Chevy350guy

They looked like they were spraying fine but I'll check it. What is the voltage to check?

You would want to test the injectors resistance. I think they should be 1-2 Ohms. Injectors should be getting battery voltage, which since they work at least somewhat they are.

I agree this could all be due to bad gas. How long have you been running it since the bad fillup? You could try unpluging the MAP sensor and see if it runs better.

Chevy350guy · 10-30-2009, 08:06 PM

It started acting up no more than 20 seconds after I started it and drove away from the gas pump. I don't have a multimeter but I will check the resisitance as soon as I get time and I'll try the water seperater but it happened pretty quickly plus I already had about half tank in it before I added more gas

inafogg · 10-31-2009, 03:16 PM

do you have a timing light??how many miles on truck??i agree the chances of
bad gas so quickly after filling.might want to verify timing is correct & it didnt
jump a couple teeth.Good Luck mike

MT-2500 · 10-31-2009, 04:24 PM

Quote:

Originally Posted by Chevy350guy

It started acting up no more than 20 seconds after I started it and drove away from the gas pump. I don't have a multimeter but I will check the resisitance as soon as I get time and I'll try the water seperater but it happened pretty quickly plus I already had about half tank in it before I added more gas

It started acting up no more than 20 seconds after I started it and drove away from the gas pump.

That should tell you something.

As stickman said check that fuel.

Chevy350guy · 11-01-2009, 10:48 PM

Thanks for all your replies I was in the desert this weekend and my iPhone died. But I am going to try the water seperater in my tank first thing in the morning. How many bottles should I use and if it is bad gas could the bottle(s) not even work or should I try new gas and just dump my tank? That would suck to waste 70 bucks of 91 octane if the water seperater doesn't work.

Chevy350guy · 11-01-2009, 10:51 PM

And I don't have a timing light. The truck has 180k on the motor

Chevy350guy · 11-04-2009, 08:38 AM

I ended up pumping the old gas out of the tank and replaced it with a few good gallons of different gas and it's doing the same thing. I think it's time to just put this truck in the shop.

manicmechanix · 11-04-2009, 02:39 PM

If you have a voltmeter, did you try checking the injectors resistance and seeing if unplugging the MAP sensor helps any?

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