Ford Sierra Cosworth ECU Prom

[Jim Pearl]

Check for a compressor bypass valve and see if it's operating correctly =
or in bad shape. When you drop off boost suddenly it will blow off the =
excess boost, when you get back on it this valve must seal up for boost =
to be produced. If it doesn't or if it didn't pop correctly then boost =
might be slow or not coming at all. I'm not positive that your car had =
one of these stock but I would expect so with it being a Cosworth...

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>From: 	Clint Sharp[SMTP:clint at clintsmc.demon.co.uk]
Sent: 	Sunday, January 07, 1996 11:38 AM
To: 	diy_efi at coulomb.eng.ohio-state.edu
Subject: 	Ford Sierra Cosworth ECU Prom

A friend has just acquired a 1989 Ford Sierra Sapphire Cosworth
and is experiencing some problems with the turbo. If the car is=20
driven on boost then all is fine until it comes off boost. When
he accelerates again the turbo doesn't produce any boost (at least=20
it doesn't feel like it, no spine snapping acceleration) and acts
like a fast 2l car. Any suggestions? (I've been elected to fix it
as he thinks it's an electrical fault) The ECU has been modified
and he hasn't got the original chip. Does anyone have a copy of=20
the standard chip they can mail me? Any suggestions as to the=20
cause of the problem would be gladly accepted.
--=20
We apologise for the lack of coherent humorous comments.
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                       clint at clintsmc.demon.co.uk