89 k1500 stalling problems

[heavyredchevy]

My truck stalls when i put it in gear, and when it is in park. It also stalls when i stop, and it ides rough. I am also having some hezitation under soft acceleration, then it goes away after i give it enough gas. I only have these problems occasionally... Since then, i have replaced: TPS sensor, Oxy sensor, MAP sensor, EGR valve, EGR solenoid, Fuel line and filter, and the Idle sensor. I also have a few mods: Flowtech headers, Flowmaster super 40's muffler, and a K&N Round Filter.

Please help me, i am totally stumped on this one.

[robertjr]

Its sounds to me like either you have your idle set to low or if you have TBI your injectors are clogged.

[heavyredchevy]

Ill try setting my idle a little higher. I do have TBI, do you think the injectors are whats causing the hesitation?
Your help is much appreciated.

[robertjr]

Yeah after a while you'll get build up that will clog the injector pretty easy to change can't remember off the top of my head how much one will run you. But while your swapping the injector you should clean out the TB housing really well. Good luck and hope this helps!

[heavyredchevy]

I had a bottle of gumout fuel injection cleaner that i added yesterday. I checked the injectors, and it looks like their spraying alright. Could anything eles be causing these problems?

Also how do i check for error codes? Do i have to take it in for this?

[bcbart82]

I have read where 89's where prone to having distributor problems. Something about magnetizing of the distributor shaft? The end result is low ac voltage produced by the pick up coil. I know this doesnt sound like it would be the cause but I'm attaching a link from this same site. Might be worth a read? Good luck!!

http://www.automotiveforums.com/vbul...d.php?t=426292

[robertjr]

Yeah their is a whole list of possiblites, I have read the link that bcbart82 put on here and it could be the problem. I would give it a look. Oh and just fyi its just about impossible to tell if injectors are functioning correctly just by looking at them. good luck buddy and if you got questions we'll be around!

[heavyredchevy]

Ill have to take a look at that... I though maybe i would see a change in the way the injectors were spraying when it starts to cut out.
Do you guys think a stoped up Cat could also be the problem?...thats the only thing i didnt change when i got my new exhaust. Its been on there for a while.

thanks for all your help

[2000CAYukon]

Originally Posted by heavyredchevy

Ill have to take a look at that... I though maybe i would see a change in the way the injectors were spraying when it starts to cut out.
Do you guys think a stoped up Cat could also be the problem?...thats the only thing i didnt change when i got my new exhaust. Its been on there for a while.

thanks for all your help

If the cat was clogged, you would have problems under wide open throttle as well. The more air thru the cat, the bigger the restriction if the cat is clogged.

The Pickup Coil can cause your problem as well as a vacuum leak.

//2000CAYukon

[heavyredchevy]

I read the link that sounds like the problem. Im almost positive the coil will fix it. I will keep you guys posted.
Thanks again for all your guys help.

[heavyredchevy]

Well i went to check if my distributer had that bad shaft, and it doesnt match the part number from the link. Their doesn't seem to be any oil getting in, and the pickup is good. I did give my injectors and throttle body a good cleaning, this did eliminate the stalling, and rough idle. But I still have the hesitation, im woundering if its the computer under my glove box, I did notice it making this loud buzzing noise when i turn the ignition on. Could this be the problem?

[robertjr]

normally the load buzzing noise is not the computer its the blower motor for the heater. I've had the same noise on every chevy I have ever owned. As far as the hesitation goes check your fuel line pressure with out enough pressure the engine will lug and hesitate under acceleration.

[heavyredchevy]

Originally Posted by robertjr

normally the load buzzing noise is not the computer its the blower motor for the heater. I've had the same noise on every chevy I have ever owned. As far as the hesitation goes check your fuel line pressure with out enough pressure the engine will lug and hesitate under acceleration.

Ill check the fuel pressure. The buzzing isnt the blower motor. The blower motor kicks in before the computer, and its a softer buzzing. The computer does it shortly after the blower, and its A LOT louder then the blower. I know its the computer because i had somone turn the ignition on and off while i was listening, and it does it when i turn it off too. Its also coming from right where the computer is. Could this effect my engine?

[sak22]

How do you adjust the idle on the TBI models??? I thought it was all electronic Sensors ie... TPS, IAC etc...?

[67malibu]

The Holley TBIs have an idle adjustment screw on the linkage arm like a carbuerator (or at least my 88 stock unit as well as the 670 CFM upgraded Holley do.) As for the hesitation, check the TPS (throttle position sensor.) My stock unit had adjustment slots so the TPS could be adjusted (loosen the screw and rotate the sensor slightly forward or backward.) I had to drill slots into the replacement to make it adjustable (I had hesitation problems until I got the TPS voltage set correctly.)