Loss of Power, backfiring - 1991 90 20vq sedan

[John S. Lagnese]

Tired fuel pump?
----- Original Message ----- 
From: "Brendan" <mailinglist at endosquid.com>
To: <quattro at audifans.com>
Sent: Sunday, July 13, 2008 10:22 PM
Subject: Loss of Power, backfiring - 1991 90 20vq sedan


> Ok, I made it a few years without wasting bandwidth, so here goes:
>
> --- *Only* when in gear in driving ---
> No matter what gear (but feels different in each gear), car will hit an 
> odd
> powerloss between 3400/3600 RPMs if accelerated slowly through that band. 
> If
> you rocket through, there is nearly no powerloss. This powerloss keeps 
> going
> unless you downshift and/or somehow accelerate quickly over 4200 RPMs or 
> so
> at which point, you feel the car drop out of wimpy and back into Hefty. If
> you stay driving in what I think of as "power loss mode", the car will
> backfire eventually.
>
> Been happening for years, but I have adjusted my manner of driving to
> compensate, namely, I just speed all of the time.
>
> New parts since problem began:
> timing belt, water pump, tensioner
> plugs, cap, rotor, wires, air fuel filters
> wheels, tranny/diff mounts
> entire suspension
> exhaust, o2 sensor, cat
> shifter
> MAF was gently washed with alcohol until clean, but not replaced
>
> Ideas? My mechanic and I are nearly out of them.
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