Odd hard starting problem??
Thread Starter
Race Director
Joined: Sep 2004
Posts: 16,271
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From: Stockton, CA
Odd hard starting problem??
I've found that when my 928 is fully warmed up and driven, then it sits for more than about an hour or two (just long enough for a nice dinner).....it will never start on the first crank...won't even fire.....then on the second crank it fires (barely) stumbles for a second then runs fine the rest of the time?
It always starts fine when its cold (but might idle a touch low at first) and always starts right up when its been fully warmed up......its odd?
It always starts fine when its cold (but might idle a touch low at first) and always starts right up when its been fully warmed up......its odd?
Under the Lift
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Joined: Mar 2002
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From: Buckeye, AZ
Brian:
This is almost classic for:
- Leaky injectors
- Bad check valve
- Bad fuel pressure regulator.
Bring your car over and we will test the fuel pressure. Here's the drill.
This is almost classic for:
- Leaky injectors
- Bad check valve
- Bad fuel pressure regulator.
Bring your car over and we will test the fuel pressure. Here's the drill.
Thread Starter
Race Director
Joined: Sep 2004
Posts: 16,271
Likes: 82
From: Stockton, CA
https://rennlist.com/forums/showthre...ight=hot+start
Spent the afternoon at Bills checking the fuel pressure.....typical 48ish at idle...increases to about 60 once the engine is off.....holds steady for about 20 minutes....then it starts to drop.....to about 12lbs at an hour.....BUT it did start no problem......more testing is required to narrow down either the regulator or check valve...... My thoughts are regulator, similar to the problem Matt had on the above link?
Other ideas
Spent the afternoon at Bills checking the fuel pressure.....typical 48ish at idle...increases to about 60 once the engine is off.....holds steady for about 20 minutes....then it starts to drop.....to about 12lbs at an hour.....BUT it did start no problem......more testing is required to narrow down either the regulator or check valve...... My thoughts are regulator, similar to the problem Matt had on the above link?
Other ideas
Under the Lift
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Joined: Mar 2002
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From: Buckeye, AZ
Brian's fuel pressure pattern kinda surprised me. Nice and steady at idle, but when you shut the car off it shoots UP and additional 5 or 6 lbs. I haven't seen that before. It sits stone stable for a good 10-15 minutes, THEN it starts to fall, It falls rather steadily and exceeds barely the spec of 0.5 bar at 30 minutes. By 45 minutes its down to only 10 PSI remaining. So, we have a leak, but the initial shoot up and rock stable pressure for 10-15 minutes fooled me.
We didn't have time to run all the tests in the troubleshooting guide. We'll get to that next time.
We didn't have time to run all the tests in the troubleshooting guide. We'll get to that next time.
