tbi problems

westtexus · 10-26-2009, 08:29 PM

hi, new user here,

I have a 1989 k2500 gmc pickup, 4x4. been having a problem in that when first starting cold engine, it runs perfectly, lots of power and acceleration. A few seconds later it starts to bog down and lose power. When started cold the tbi does not dribble, then when the problem starts, stop and look again, tbi is dribbling. no trouble codes, just replaced fuel pump, thinking it had low pressure, no change. anyone have this problem before, or any thoughts on this?

thanks in advance

silverhairdeere · 10-26-2009, 09:45 PM

maybe your fuel pressure regulater , or clogged injectors . some one will chime in

shd

BernieB · 10-26-2009, 10:26 PM

If the injectors are dribbling when they're warm, chances are they're gummed up. You can try cleaning them, and running some injector cleaner through the tank also.

rdhack · 10-26-2009, 11:08 PM

SEAFOAM should do the trick Make it s strong mix at first

gmctrucks · 10-26-2009, 11:58 PM

Look on You-Tube on how to apply by using brake booster line that will clean them good.

westtexus · 10-27-2009, 04:50 AM

i have never heard of or used seafoam. as to the brake booster hose, will that go through the injectors, or just into the throttle body?

mudseeker · 10-27-2009, 06:38 AM

Quote:

Originally Posted by westtexus

i have never heard of or used seafoam. as to the brake booster hose, will that go through the injectors, or just into the throttle body?

none, goes through the intake.

Crmzendrgone · 10-27-2009, 01:42 PM

The only way to get SOME through the injectors them self is to put in the tank. The real only good way is to have some kind of tool (I've only seen shops with them) that bypasses the fuel line and the chemical is sucked straight out of it no fuel.

Chevy_Finatic79 · 10-27-2009, 01:49 PM

crmzen is right there is no way to truly clean in jectors without a special tool but the lucas injector cleaner additive seems to help you pour it into the tank the ratio is on the bottle be sure not to put too much in like i did it will run bad if the mix is too strong, a

lso if the throttle body has never been rebuilt you might want to do that or have it done for you, the diaphram (fuel pressure regulator) goes bad after about ten years and lets too much fuel go thru the injectors causing the dribble,

just a thought but you might have a bad computer coolant sensor the 2 wire yellow & black one when its warm unhook it and see if the fast idle kicks in

Crmzendrgone · 10-27-2009, 02:29 PM

Ooo what is this about a coolant sensor I had this problem a while ago and rebuilt the TBI and got a new regulator but it still seems to run fat. So if the idle kicks up then that means what?

10-26-2009, 08:29 PM	#1
westtexus Junior Member Join Date: Oct 2009 Posts: 2	tbi problems hi, new user here, I have a 1989 k2500 gmc pickup, 4x4. been having a problem in that when first starting cold engine, it runs perfectly, lots of power and acceleration. A few seconds later it starts to bog down and lose power. When started cold the tbi does not dribble, then when the problem starts, stop and look again, tbi is dribbling. no trouble codes, just replaced fuel pump, thinking it had low pressure, no change. anyone have this problem before, or any thoughts on this? thanks in advance

10-26-2009, 10:26 PM	#3
BernieB Senior Member Join Date: Jul 2009 Location: Fredericksburg, VA Posts: 1,902	If the injectors are dribbling when they're warm, chances are they're gummed up. You can try cleaning them, and running some injector cleaner through the tank also. __________________ If the guys who design 'em had to take one home, use it every day for 2 years, and do all the maint and repairs themselves, cars would have a button on the dash to change the oil, filters & plugs.

10-26-2009, 11:08 PM	#4
rdhack Senior Member Join Date: Jun 2008 Location: kentucky Posts: 165	SEAFOAM should do the trick Make it s strong mix at first __________________ MY first truck was a FORD.......I've owned Chevy's ever since. 1995 K2500 4x4 5.7L Cheyenne 1991 T-10 Blazer 4.3L Tahoe Package 2000 Ford Taurus - Spouses

10-27-2009, 01:42 PM	#8
Crmzendrgone Senior Member Join Date: Apr 2009 Location: Arizona Posts: 1,420	The only way to get SOME through the injectors them self is to put in the tank. The real only good way is to have some kind of tool (I've only seen shops with them) that bypasses the fuel line and the chemical is sucked straight out of it no fuel. __________________ ENGINES PRODUCE POWER. MOTORS RECEIVE POWER. https://lastroundbestround.com/Home_Page.html

10-27-2009, 01:49 PM	#9
Chevy_Finatic79 Senior Member Join Date: Mar 2008 Location: Lincoln NE Posts: 478	crmzen is right there is no way to truly clean in jectors without a special tool but the lucas injector cleaner additive seems to help you pour it into the tank the ratio is on the bottle be sure not to put too much in like i did it will run bad if the mix is too strong, a lso if the throttle body has never been rebuilt you might want to do that or have it done for you, the diaphram (fuel pressure regulator) goes bad after about ten years and lets too much fuel go thru the injectors causing the dribble, just a thought but you might have a bad computer coolant sensor the 2 wire yellow & black one when its warm unhook it and see if the fast idle kicks in __________________ "She's gonna Freak when she see's my wheels" 85' Chevy C-10 Longbox (Rat) TBI 327 Cu.In./THM350 90' Chevy Suburban 4x4 TBI 350 Cu.In./700R4 http://www.truckforum.org/forums/truck-pictures-176.htm

10-26-2009, 09:45 PM	#2
silverhairdeere Senior Member Join Date: Feb 2008 Location: land between the lakes tn Posts: 1,184	maybe your fuel pressure regulater , or clogged injectors . some one will chime in shd

10-26-2009, 11:58 PM	#5
gmctrucks Senior Member Join Date: Nov 2006 Location: Houston,Texas Posts: 4,033	Look on You-Tube on how to apply by using brake booster line that will clean them good.

10-27-2009, 04:50 AM	#6
westtexus Junior Member Join Date: Oct 2009 Posts: 2	i have never heard of or used seafoam. as to the brake booster hose, will that go through the injectors, or just into the throttle body?

10-27-2009, 02:29 PM	#10
Crmzendrgone Senior Member Join Date: Apr 2009 Location: Arizona Posts: 1,420	Ooo what is this about a coolant sensor I had this problem a while ago and rebuilt the TBI and got a new regulator but it still seems to run fat. So if the idle kicks up then that means what? __________________ ENGINES PRODUCE POWER. MOTORS RECEIVE POWER. https://lastroundbestround.com/Home_Page.html

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