At a Loss With Loss of Power - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Street Sweeper · 07-11-2012, 09:57 PM

First - Im new to this side of the forum - Ive got a '65 suburban that I'm building - I spend most of my time on the 60-66 stuff. Sorry if this question is a repeat of someone else's.

My son is driving a '94 Blazer - all original. The truck idles fine. Once it gets up to speed it runs fine. The transmission shifts fine. At about 1/4 throttle in gear it bogs down and almost comes to a stop. Eventually it picks back up and will run out OK. Im scared he's going to get run over.

We changed the fuel filter (no help). Two different mechanics looked at it and diagnosed it as "needing a tune-up" with new plugs, wires, dist. cap, and rotor. We changed plugs, wires, rotor, and distributor cap. This seemed to correct the problem for about 5 days. Today, as he started to leave a red light, it started doing the same thing again.

I changed the coil tonight but it didn't make any difference.

Can anybody shed some light on what might be going on with this thing before I go outside and set fire to it?

Any help would be appreciated.

ChevyTech · 07-11-2012, 10:25 PM

To much EGR flow can cause a stumble, hesitation, stalling, lack of power…

You could try disconnecting and plugging the vacuum hose to the EGR valve and taking it for a test drive.

If you find it does need an EGR valve, I would suggest only using an OEM (Original equipment manufacturer) replacement EGR valve. These TBI truck are very picky about the EGR valve operation.

ChevLoRay · 07-12-2012, 10:27 AM

Since you are new to this forum...you should know that what ChevyTech says...you can take to the bank.

ChevyTech · 07-12-2012, 11:34 AM

Thank you ChevLoRay!

If the EGR test does not make a difference then you need to test the fuel pressure with the engine running. There is information on this in the FAQs sticky at the top of this board.

07-11-2012, 09:57 PM	#1
Street Sweeper Registered User Join Date: Jan 2010 Location: Marietta, GA Posts: 62	At a Loss With Loss of Power First - Im new to this side of the forum - Ive got a '65 suburban that I'm building - I spend most of my time on the 60-66 stuff. Sorry if this question is a repeat of someone else's. My son is driving a '94 Blazer - all original. The truck idles fine. Once it gets up to speed it runs fine. The transmission shifts fine. At about 1/4 throttle in gear it bogs down and almost comes to a stop. Eventually it picks back up and will run out OK. Im scared he's going to get run over. We changed the fuel filter (no help). Two different mechanics looked at it and diagnosed it as "needing a tune-up" with new plugs, wires, dist. cap, and rotor. We changed plugs, wires, rotor, and distributor cap. This seemed to correct the problem for about 5 days. Today, as he started to leave a red light, it started doing the same thing again. I changed the coil tonight but it didn't make any difference. Can anybody shed some light on what might be going on with this thing before I go outside and set fire to it? Any help would be appreciated.

07-11-2012, 10:25 PM	#2
ChevyTech Registered User Join Date: May 2004 Location: Minnesota Posts: 4,621	Re: At a Loss With Loss of Power To much EGR flow can cause a stumble, hesitation, stalling, lack of power… You could try disconnecting and plugging the vacuum hose to the EGR valve and taking it for a test drive. If you find it does need an EGR valve, I would suggest only using an OEM (Original equipment manufacturer) replacement EGR valve. These TBI truck are very picky about the EGR valve operation. __________________ For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If it is modified from what came stock from the factory, let us know that too.

07-12-2012, 10:27 AM	#3
ChevLoRay Old Skool Club Join Date: Jun 2001 Location: Benton, AR "The Heart of Arkansas" Posts: 10,880	Re: At a Loss With Loss of Power Since you are new to this forum...you should know that what ChevyTech says...you can take to the bank. __________________ Member Nr. 2770 '96 GMC Sportside; 4.3/SLT - Daily driven....constantly needs washed. '69 C-10 SWB; 350/TH400 - in limbo The older I get, the better I was.

07-12-2012, 11:34 AM	#4
ChevyTech Registered User Join Date: May 2004 Location: Minnesota Posts: 4,621	Re: At a Loss With Loss of Power Thank you ChevLoRay! If the EGR test does not make a difference then you need to test the fuel pressure with the engine running. There is information on this in the FAQs sticky at the top of this board. __________________ For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If it is modified from what came stock from the factory, let us know that too.



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