LT1 with WOT problem - Team Camaro Tech
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post #1 of 5 (permalink) Old Jul 27th, 12, 03:01 PM Thread Starter
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Markus
 
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Location: Germany
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LT1 with WOT problem

Hello!

My 69'Camaro with a LT1 worked well for years. Now it's not possible any more to get 5500 rpm without any surging. Because I have problems with the fuel pick up in the original tank, surging was a problem all over the years with a too low fuel level. Now I notice that surging is happened with a filled tank. The last months I changed several things:
fuel filter before fuel pump
Fuel line diameter from 12 to 9,5 mm
GMPP hot cam kit with "original" chip (during installation I saw that the distributor is ok)
Crane cams ignition module

I notice a loud fuel pump noise during driving even at idle (choppy due to the cam), but below 5000 rpm everything is ok. The fuel pump is a Bosch 10 years old, 20000miles

For the next step I will measure the fuel pressure `> Any other ideas???

69`Camaro, 92`LT 1 / 94' BW-6 speed, shorty headers+Flowmaster, Vette wheels, Eibach/hotchkis springs, koni shocks, Nova rear, Corvette 13" front brake system
[all certified by German association for technical inspection with Oldtimer title]
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post #2 of 5 (permalink) Old Jul 27th, 12, 03:16 PM
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John
 
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Re: LT1 with WOT problem

I think you're on the right path - monitor the fuel pressure

It is common for fuel pumps to have a finite life span - 10 years seems pretty good to me depending on use, I get @6~7 on most marine applications before I've seen problems ...

I'm not a fan of a filter prior to a pump in many applications, specially 'lift' type pump locations.
They can cause or contribute to cavitation of the impeller and show-up as fuel delivery/starvation issues.

I will usually install a visible gauge on vehicles when chasing these problems.
Then I can monitor it throughout the ranges problems have occurred and see the outcome.

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Some trucks
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post #3 of 5 (permalink) Old Jul 27th, 12, 08:00 PM
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Scott
 
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Re: LT1 with WOT problem

I agree. This sounds like a fuel supply problem. Monitoring the fuel pressure is the first step.

Another thing to consider is fuel tank venting. I went through a similar situation many years ago when still running a carburetor. I finally tracked it down to a spider web in the gas cap vent. Under heavy loads the fuel demand would pull the tank into enough vacuum so the mechanical pump couldn't do its job and power would flatten off badly at higher revs. It also showed up as a loss of fuel pressure which definitely sent me down the wrong road for a while.

67 Camaro, 96 LT1, 4L60E
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post #4 of 5 (permalink) Old Jul 27th, 12, 11:00 PM
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Steps
 
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Re: LT1 with WOT problem

Quote:
The fuel pump is a Bosch 10 years old, 20000miles
I dont think the miles is an issue but that long sitting in fuel...
For the price of a pump, and considering its age, I would not even bother monitoring pressure, just replace then go from there knowing that is not the issue IF it still exists.

My Spelling is not incorrect...it is creative

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post #5 of 5 (permalink) Old Jul 28th, 12, 07:26 PM
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Jason
 
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Re: LT1 with WOT problem

First thing I would do is replace is the fuel pump. If that doesnt do anything the opti would be next on my list.

Jason
2009 CTS-V - 1968 Camaro 327/M20 Sequoia Green
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