[urq] A/F ratios under varying conditions

[Brandon Rogers]

Brady- I think you touched on what may be your problem, but did not give any
detail.  What _are_ your fuel pressures?  Have you hooked up a fuel pressure
gauge and watched it climb as engine temp rises.  what is the system
pressure?  What is the warm control pressure?  Many a person have said on
this list that the three most important things with CIS are: 1. fuel
presssure 2. fule pressure and 3. feul pressure.  Good luck.

Brandon
'84 ur




----- Original Message -----
From: "Brady Moffatt" <bradym at sympatico.ca>
To: "urq" <urq at audifans.com>; "quattro" <quattro at audifans.com>
Sent: Thursday, May 22, 2003 12:00 AM
Subject: [urq] A/F ratios under varying conditions


> Hi All,
>
> Trying to troubleshoot the stumble under load/boost on my 83 UrQ. The car
> has a Lehmann ECU and SQ WG spring and diaphragm along with a nice ricey
> blow-off valve. I hate to admit it, but I'm getting addicted to its
> pssssshhhhttt sound. The car stumbles under load as of 4K in 4th and 3200
or
> so in 5th.
>
> Martin Pajak wisely suggested I get an A/F meter so I could get an idea if
I
> was about to blow up my engine. I bought an APEXi Turbo Timer that also
> displays A/F ratio, O2 sensor (which is new and cycles beautifully)
voltage,
> and battery voltage. Well, here's what it shows: At almost all times, the
AF
> ratio is 14.5:1  + or - 0.5.  The only time it goes down below 14 is on a
> shift when the BOV opens and it drops to 12.5 at the lowest. Under boost
at
> light to mid throttle up a small hill in 5th today, I saw the ratio creep
up
> to 17. That scared me. If I floor it, my ratio may go down from 14.5 to
> 14.2, but not to 12 which is where max power is.
>
> I'm a bit worried. Combine that problem with a hard cold start (warm and
hot
> starts are fine), and I'm leaning towards fuel pressure ills.
>
> What are the normal AF ratios that these cars perform in? Am I running way
> lean?
>
> Cheers,
> Brady Moffatt
> Montreal, Quebec, Canada
> 83 UrQuattro with 52,000 miles
> 86 4ksq with 310,000km
> 86 4ksq parts car
> 72 Datsun 240Z with 180,000 miles
> 92 VW Golf with 200,000km FOR SALE
> in middle stages of quattrosis accumulatus
>
>
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