Check your cold start air enrichment valve.  It is buried under the
hoses on the right side of the engine, and one of those hoses will lead
right to it from the intake plenum.  It allows more air, and hence fuel,
during warm up by bypassing the AFM with extra air.  It is heated
electronically, which closes it when the engine is warm.  Bentley has
the procedure for testing, but is sounds like it is stuck shut and not
doing its enrichment thing.

Mark Smith wrote:
>
> Dear list,
>
> My 87 GL is exhibiting the following symptoms upon cold startup or after
> being parked for several hours. Anyone familiar with these symtoms? Your help
> will be greatly appreciated.
>
> It starts easily and idles smoothly at 1000 rpm for 20 to 30     seconds.
> Then it starts missing slightly and gradually worsens
> until the engine dies after another 20 to 30 seconds.
>
> The engine easily restarts each time it dies and repeats the above process
> until the temperature guage gets just below the warning light, afterwhich it
> runs perfectly. Trying to keep the revs up slightly does not help.
>
> It usually requires 10 or 12 startups and 10 or more minutes to get past this
> problem. The bus runs beautifully after its warm and does not have this
> problem after parking for up to 2 hours once the engine is warm.
>
> I have relaced the ignition wires, spark plugs, and the blue temperature
> switch located on the thermostat housing. I have ordered a new O2 sensor to
> install this week. So far nothing has helped my problem. Any ideas?
>
> Thanks for your help.
>
> Mark Smith
> 87GL
> "Jimmy Joe"

--
Stuart MacMillan
Manager, Case Program
800-909-8244 ext. 8208
Fax: 206-269-6360

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