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Old 09-04-2008, 05:46 PM   #1
sjfarbs
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Default Hard to Start When Cold

Hey gents.

Hope to have some light shed on my starting issue. I have a 84' L Jet.

Problem that has just come up is that I have a hard time starting when cold, first thing in the morning. It will start after a number of cranks, and a slight goose to the throtle.

Now after it starts for the first time in the morning, it will fire up on the first turn of key all day long.

Things I have checked have been temp II sensor & FP check valve.

I was wondering if it has anything to do with the cold start valve and cold start injector not delivering enough fuel on the first cold start. Maybe the injector is clogged or the valve not operating as it should.

Any insight would be appreciated of where to start and how to test. I am a bit of novice, so speak slowly

Thanks and let me know what other info I can provide to help T/S the issue.

Shawn
84' 928S
74'Triumph TR6
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Old 09-04-2008, 10:00 PM   #2
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Very possibly... if your coolant temperature sensor wasn't kicking your cold start injector on, the motor might not be getting enough fuel to start right off.

Some new spark plugs usually do wonders w/ cold starting...

Replace the sensor for a start (no pun intended), then see where you're at.
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Old 09-04-2008, 10:07 PM   #3
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Thanks khooper..................by coolant temp sensor, do you mean the Temp Time Switch for the cold start valve? The Temp II sensor did test within spec when cold.

I hear ya on the plugs, could always use a refresh I guess.............but the car fires great on the first turn, after the initial cold start issue, so wouldn't that rule out bad plugs?

Thanks.
Shawn
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Old 09-05-2008, 12:16 PM   #4
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So I checked the Temp Time Switch...........it was hard to get a reading because as soon as I would make contact, my digital metar would jump and fluctuate then go right to 0.

So here are the results, cold engine..........sat overnight:

W Term to ground on housing--- first contact jumps to maybe .096 then down to 0
G Term to ground on housing-----same thing jumps to maybe .048 then down to 0
W to G Term----same thing, jumps a bit .042 then right to 0.

So either I am measuring wrong, not making a strong contact or the sensor is bad.

Can someone jump in and give me some advice?

Thanks!
Shawn
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Old 09-05-2008, 02:08 PM   #5
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Check your fuel pressure in the morning. There is a good chance that there is no fuel in your fuel rail first thing in the morning, but after you've fired it up the first time, there is fuel. Problem could possibly be the check valve down on the fuel pump at the tank. Pretty easy and quick fix if that's it.
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Old 09-05-2008, 02:50 PM   #6
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I was thinking that too, FP check valve. But I did the "test" according to the
928 Specialist web site, which is to just turn the key about 4 times in a row, without letting the engine turnover, this should cycle enough fuel into the rail for it to fire. I did that test, to no avail.
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Old 09-05-2008, 03:00 PM   #7
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I think you have to turn the engine over - but not start- in order to test the check valve.
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Old 09-05-2008, 05:43 PM   #8
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Here are the instructions off the 928 Specialist site:

"Let your 928 sit overnight or at least 8 hours or so. Instead of trying to start the car as you normally would, turn the key so you engage the starter for just a second and turn the key back off (do not let the car even try to start), do this 3 or 4 times in a row. Then try to start it like you normally would, if it starts OK at this point then it is most likely the fuel pump check valve."

That is what I was trying to say...............if I implied that I did not engage the starter, my bad.
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Old 09-05-2008, 05:43 PM
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