TBI problem - The 1947 - Present Chevrolet & GMC Truck Message Board Network

streetstar · 12-31-2007, 07:29 PM

having a tbi prob with my Blazer, but i know this could be an issue with any tbi truck.

When its cold, it hesitates and almost dies when i hit the throttle from a dead stop (WFO, not a gradual opening) but if i travel 100 ft and then nail the throttle , it goes like stink.
it also takes 3-5 minutes to warm up to this performance level, but i have to drive it for 30 minutes it seems before it starts working optimally

Let me know any ideas possible before i R&R everything electrical under the hood. Its not a daily driver - so no a dire emergency or anything

(a running joke among a couple of mechanics i know is that anytime they take in an aviation guy's truck for repair, its bound to have new wires, plugs, dizzy cap, alternator, batt. or starter -------- people will sometimes try anything before they have to face the truth)

89 crew · 12-31-2007, 09:10 PM

check the injector spray. my 89 350 tbi had that problem. a simple dose of injector cleaner over the next couple tank fulls cured it. but my injectors were not spraying right.you should look for a pretty cone spraying down from the injectors. if it isn't right or they are not the same then I would say that is your problem.

BLE 'BURBAN · 01-01-2008, 01:05 PM

An easy way to light up your tbi spray pattern is to hook up a timing light and point it at the tbi unit while the engines running. The strobe effect will help you to see any fluxuations in the spray pattern

streetstar · 01-01-2008, 08:53 PM

Quote:

Originally Posted by BLE 'BURBAN

An easy way to light up your tbi spray pattern is to hook up a timing light and point it at the tbi unit while the engines running. The strobe effect will help you to see any fluxuations in the spray pattern

Should i be playing "Dark Side of the Moon" in the background with the Wizard of Oz on tv?

Kidding --- thx all for the advice ------- now back to my Pink Floyd jam session

tylerdurden · 01-23-2008, 03:23 AM

If you had a way to read data you check out the coolant temp sensor(intake manifold), not the temp gauge (driver side cylinder head). Check the idle air control valve (IAC) to see if the cone is carbon up or sitting crooked.

12-31-2007, 07:29 PM	#1
streetstar Registered User Join Date: May 2007 Location: Moore, Oklahoma Posts: 2,396	TBI problem having a tbi prob with my Blazer, but i know this could be an issue with any tbi truck. When its cold, it hesitates and almost dies when i hit the throttle from a dead stop (WFO, not a gradual opening) but if i travel 100 ft and then nail the throttle , it goes like stink. it also takes 3-5 minutes to warm up to this performance level, but i have to drive it for 30 minutes it seems before it starts working optimally Let me know any ideas possible before i R&R everything electrical under the hood. Its not a daily driver - so no a dire emergency or anything (a running joke among a couple of mechanics i know is that anytime they take in an aviation guy's truck for repair, its bound to have new wires, plugs, dizzy cap, alternator, batt. or starter -------- people will sometimes try anything before they have to face the truth) __________________ Are you retired too? Nonsense! I'm in my prime Last edited by streetstar; 12-31-2007 at 07:30 PM.

12-31-2007, 09:10 PM	#2
89 crew Registered User Join Date: Mar 2006 Location: Kansas Posts: 865	Re: TBI problem check the injector spray. my 89 350 tbi had that problem. a simple dose of injector cleaner over the next couple tank fulls cured it. but my injectors were not spraying right.you should look for a pretty cone spraying down from the injectors. if it isn't right or they are not the same then I would say that is your problem.

01-01-2008, 01:05 PM	#3
BLE 'BURBAN In the Forgotten far North. Join Date: Jul 2007 Location: Anchorage, Alaska Posts: 2,627	Re: TBI problem An easy way to light up your tbi spray pattern is to hook up a timing light and point it at the tbi unit while the engines running. The strobe effect will help you to see any fluxuations in the spray pattern __________________ 1987 R3500 CREW CAB DUALLY (BIG RED)Acquired 06/12/2015 1990 chevy suburban V2500 5.7L My cluster Mods-Nov 2007 overhead console Stereo install Round 2 Aug 2009 Heated/turn signal mirror upgrade

01-23-2008, 03:23 AM	#5
tylerdurden Registered User Join Date: Sep 2005 Location: Austin, TX Posts: 20	Ckeck two other things If you had a way to read data you check out the coolant temp sensor(intake manifold), not the temp gauge (driver side cylinder head). Check the idle air control valve (IAC) to see if the cone is carbon up or sitting crooked.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.