problem with my '94 Chevy

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Jan 20, 2008 | 06:12 PM

#11

MaxFubar

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From: Dallas, TX

Quote:

Originally Posted by YenkoST

How's your compression looking...do a compression test.

Compression checks out. All around 150-ish.

Jan 22, 2008 | 08:40 AM

#12

shandy294

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From: Cibolo Tx

fuel press chk couldn't hurt...is it still on the original pump?

Jan 22, 2008 | 12:07 PM

#13

MaxFubar

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From: Dallas, TX

Quote:

Originally Posted by shandy294

fuel press chk couldn't hurt...is it still on the original pump?

Delco pump installed 50K miles ago, fuel filter changed every 10K. Pressure checks out. Still looking for ideas

Jan 22, 2008 | 12:16 PM

#14

White Lightnin

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From: Norman, Oklahoma

Had a 98 z71 that did the same thing. It turned out to be the fuel pump. It would backfire and act like trans was slipping.

Jan 22, 2008 | 01:25 PM

#15

YenkoST

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From: GA

Quote:

Originally Posted by MaxFubar

Compression checks out. All around 150-ish.

Compression is low...should be about 190-205-ish.

Stock tune or modified tune?

Jan 22, 2008 | 03:23 PM

#16

MaxFubar

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From: Dallas, TX

it's stock, I though 140 to 160 was ok.

Jan 22, 2008 | 03:26 PM

#17

YenkoST

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From: GA

Naw...a stock engine on compression psi should be 190-205.

Jan 23, 2008 | 02:38 PM

#18

dschmittie1

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From: York, PA

Quote:

Originally Posted by YenkoST

Naw...a stock engine on compression psi should be 190-205.

Yeah maybe but he said it has 300k miles on it and 140-150 isn't bad for that many miles on a 5.7

Jan 23, 2008 | 02:43 PM

#19

YenkoST

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From: GA

Yea, I understand it has 300k on it but low psi means fuel/air is getting by which could be causing a leaner condition when off the throttle.

Other than that, its timing related. If you have advanced the timing at the distributor, set it back to "0" stock with the EST line disconnected. If you haven't touched it, advance it 4 degrees and see what happens.

Jan 23, 2008 | 11:24 PM

#20

Slo-Mo-Shun

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From: Tyler, Tx

Quote:

Originally Posted by oldred95

A handy way to probe your wires without puncturing the insulation is to strip about 3 or 4 inches of a piece of scrap wire and seperate out a couple or strands, twist those and then unplug the throttle position sensor and place them in the terminals and then fold the excess wire back towards the harness and plug the connector back in. Some say this will spread the terminals but if you only use a couple strands it shouldn't and it is a simple way of probing without puncturing the harness.

Another easy way is to slide a straight pin between the weather tight rubber seal and the wire insulation on the backside of the harness connector. The objective is to make contact with the backside of the "pin" inside the connector. This will not spread the terminal. This terminology is called "back probing."