Fw: Odd engine problem on a rainy day . . chug, chug, chug, chug

[Kneale Brownson]

How old are the plugs, wires, cap & rotor?

At 04:42 PM 1/6/2004 -0500, SJ wrote:
>Update 2    -  90 100q
>
>Yesterday the outside temperature was in the low 30's, rainy day.
>Went to start the car. Cranks fine, I can hear one or two cylinders try to
>catch. No start.
>Tried it 4 or 5 times. Tries to catch once in a while, but wont start.
>I spray the ignition wires and ignition related parts with wd-40. Close the
>hood and leave the car alone.
>
>Today
>Colder, and dry  . . temp must be in the high 20's . .snow flurry here and
>there.
>Put the battery charger on for couple of hours . . just in case I took too
>many amps out yesterday.
>
>Pull a yellow plug in the black rubber intake air boot, attach a rubber
>hose, and set up for injecting starter fluid.
>I figure I have a temp sensor problem and cold start valve is not turning
>on.
>Standing by . . .wife cranks the engine . . .goes over once, twice .
>.vroooooom!
>
>Shit!
>
>Historical Summary so far:
>
>1 time - cold damp day, cold start, short drive, shut off engine, restart in
>15 minutes, chug chug chug for 6-10 seconds
>
>1 time - dry warmer day, cold start, short drive, shut off engine, restart
>in 15 minutes, chug, chug for few seconds.
>
>1 time - wet cold day, cold start, wont start . .. sounds like it tries to
>start on one or two cylinders.
>next day - cold dry day, cold start, starts right up.
>
>Who has some good clues for me? I'm leaning in the direction of the ignition
>system.
>But, it could also be some temperature sensor that is messing up the fuel
>injection.
>
>There are two water sensors at the top front of the engine. The bottom
>sensor is the MTF, and the top sensor I think controls how long the cold
>start valve stays on.
>Are there any other temperature sensors used by the computer?
>Would an intermittant idle switch cause this problem?
>I'm ready to swap out parts.
>
>SJ
>
>= = = = = = = = = = = = = = = = = = = = = = = = = = = == = = = =
>
>> Update:
>> Went to same store today, afternoon. Sunny dry day, temp was about 45-50.
>> One mile drive.
>> Started car after it sat for about 10 - 15 minutes.
>> Started ok, rough idle . .gas peddle had no effect. Cleared up in about
>5 -
>> 10 seconds. Some hesitation when coming off idle. After a few minutes it
>> cleared up . .no more problems.
>>
>> I think the Ignition is eliminated as the cause of the problem.
>> I'm thinking one of the temperature sensors is telling the CPU that the
>> engine is fully warmed up when its not, and I'm getting a lean mixture.
>>
>> How many temperature sensors are there? Is the MFT sensor the main one
>that
>> I should be looking at?
>>
>= = = = = = = = = = = = = = = = = = = = = = = = =
>
>> Sent: Thursday, December 25, 2003 12:32 PM
>> Subject: Odd engine problem on a rainy day . . chug, chug, chug, chug
>>
>>
>> > It was cold, foggy, and raining yesterday. Temperature was about 50 F.
>> > Oregon style weather.
>> >
>> > Drove the 90 100Q to the store . .about 2 miles away. Parked and shut
>off
>> > engine.
>> >
>> > Came out of store in about 20 minutes, started engine.
>> > Started up ok, but sounded like it was running on one cylinder. Pressing
>> > down on gas pedal did not change the RPM . . .chug, chug, chug, chug . .
>.
>> .
>> > sounded like a one cylinder diesel engine on the African Queen.
>> >
>> > I let it run this way for about 30 seconds or so . .figuring it was wet
>> and
>> > something in ignition was misfiring. Maybe it would dry out a bit.
>> >
>> > After about 30 seconds or so, the problem cleared up, no more chugging,
>> gas
>> > pedal worked.
>> > I drove home gingerly. There might have been a slight hesitation or
>> stumble
>> > going from idle to part throttle . . I'm not sure. I was very easy on
>the
>> > throttle because I didnt want to be towed home.
>> >
>> > Today, I sprayed the ignition wiring, coil, booster with WD 40. Weather
>is
>> > sunny, dry, 35 F.
>> > Car started up with no problem. No missing, no hesitation.
>> >
>> > The ignition wires and cap and rotor are about 1 year old. Maybe 4k
>miles
>> on
>> > them. Same for the plugs.
>> > ISV valve was cleaned about 500 miles ago . . nothing was wrong with it
>.
>> > .just preventive maintenance.
>> >
>> > Any ideas?
>>
>>
>
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