89 S15 Jimmy 4.3 T.B.I. Auto Trans.

Was driving around all day without any problems. This afternoon I started it up and suddenly it couldn't hold idle. It would start up and start to surge about 2 times then die out. I found a few broken vacuum lines and replaced them.

I can hear the pump priming and i have looking down the opening of the TBI and i do see gas shooting out. I did notice that if i was to disconnect the vacuum line to this piece ( dont know the name to it, but i took a pic ) the idle gets better.





I then took it out to see what it would do. It can sorta keep idle, but lost all power. I had a hard time getting it into my apt complex.

Is there anything that i might be over looking?

I grew up working on cars that the only computer it had was the radio, so with these electronics, i'm at a loss.

Any help would be appreciated.

 

That is your MAP sensor.

 

Do you have a check engine light on? Could be the MAP sensor or a vacumn leak somewhere.

 

Well here is an update.

I changed the MAP and Coolant sensor. Replaced the FPR and cleaned out the injectors. Changed my Fuel Filter and adjusted the idle. NOw the car will hold steady idle but will hesitate badly when taking off.

I was starting to suspect that it could have been the coil. I checked the spark and its not really a clean BLUE spark, but a bit yellowish at times Leading me to think that its my coil. But after checking with a DMM, all the readings are within specs.

So maybe now its either the Cap and Rotor or even my Wires. I wont be able to work on it for a few weeks due to me moving to another apt and having to spend money on that ( oh what fun ).

I'll see what happens after that is changed.

 

Final update:

I changed the cap, rotor, and wired. Then i finally checked the fuel pressure.........3lbs. GROOVY!!!!

So now i get a new pump and strainer and drop the tank. Turns out that the pump was fine. The hose that connects the pump to the sending unit had a cut in it. I was loosing pressure from there.

So i replaced the pump, hose and strainer.

Fire it up and she growls at me like trying to say, " Its about time you fixed me!". Now all the is left is to get it smogged, tagged, and insured.

What a trip.

 

I am glad you got it fixed. It is great that you posted what ultimately fixed your problem as it lets others know things to check if they are having simular problems. I always hate it and also relieved when I am troubleshooting something for a long time and when it comes down to something very simple to fix but to get there was a struggle.

 

So after doing all that, i still had to smog it. it FAILED. So now the 02 sensor had to be changed, the TBI gasket, and timing adjustment.

Fed it some Seafoam into the brake booster vacuum line and some in the tank. It passed with flying colors. So no its on the road, registered, insured, and gassed up.

WOOHOO!!!

The End.

 

Dump a can of Restore in it and wait about a week! It will really pick up some oomph! I have 250,000 miles on mine and it runs like a new truck! I never had any luck with the Sea Foam though.