Warm start problem
#1
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Hi guys,
I was having a problem before on starting up when the engine was warm. Say once I reach home and let the car cool down for a few hrs, than try starting it up, it would take many many cranks before it would start and that to it would start like only at around 500rpm. I changed the warm up regulator and still the same problem. Recently I changed my fuel pump to the 996gt2 fuel pump which I bought from Imagine Auto hoping to solve this problem but I'm still facing the same problem. What needs to be changed? Stephen or any of you guys have the solution?
The car fires up totally fine on cold start ups.
I was having a problem before on starting up when the engine was warm. Say once I reach home and let the car cool down for a few hrs, than try starting it up, it would take many many cranks before it would start and that to it would start like only at around 500rpm. I changed the warm up regulator and still the same problem. Recently I changed my fuel pump to the 996gt2 fuel pump which I bought from Imagine Auto hoping to solve this problem but I'm still facing the same problem. What needs to be changed? Stephen or any of you guys have the solution?
The car fires up totally fine on cold start ups.
#3
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I see that you replaced the accumulator about a year ago. Was this replaced because of a warm start problem? I have seen several times that they rarely fail, but that is apparently what was wrong with mine. It had the same symptoms you describe. I also tested fuel pressures and soon after the car was shut off the pressure would drop to zero. I think this was leading to vapor lock. After replacing the accumulator, it held 30 lbs when the car was shut off and it now starts fine warm or cold. I tried to find a check valve first, but was unsuccessful, ANYWHERE!
#4
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scphelps1,
I was told by my mechanics that it's most probably my fuel distributor might be leaking since I've already changed about everything. If it is the fuel distributor, than changing it is going to be very costly.
I was told by my mechanics that it's most probably my fuel distributor might be leaking since I've already changed about everything. If it is the fuel distributor, than changing it is going to be very costly.
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Sameer - you could pull the fuel distributor off and send it to the CIS fuel head guy that reflowed my fuel distributor. Stephen can help you with this. I think the charge is around $300 US to have the fuel head rebuilt and another $150 or so if you want it improved for better fuel flow (which is what I did).
#7
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Bill,
Thats a good idea. I will contact Stephen frm IA when ready to have it done. You mentioned having it improved for better fuel flow. Does this enrichen the fueling or just gives a better flow?
Thats a good idea. I will contact Stephen frm IA when ready to have it done. You mentioned having it improved for better fuel flow. Does this enrichen the fueling or just gives a better flow?
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#8
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There is a lot of talk of this on 911turbo.com. I believe it is supposed to make it more like the ROW version. It's my impression that it is supposed to flow better, but not necessarily enrich under load, as some of the other devices (Andial or Rice), that use the WUR to enrich fuel under load.
#9
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I will chime in on this one, first you can get your US head not only converted to a Euro spec but with more fuel. I was the first to try this out though getting more fuel from my Euro head and it worked. 17% more fuel across the board and now there getting up to 21% more. No fuel extra fuel enrichment needed. $500 to get the head rebuilt, increase the fuel and each port flow matched and then just use your stock WUR and your golden. Then you can run a 1.5% CO for better gas mileage at idle and cruise.
The next step is what I'm going to do, use an rpm activated switch and module ($90) not including a 12v solenoid NC switch (can use the one from your A/C) to enrich by RPM (around 5k) so you can get the most fuel possible up top without running too rich down low. Here you would need to customize your enrichment setting to around 2.4bar like Lee does. This application would be used for 400+rwhp 930's only. Only at this enrichment will you max out the fuel pin or close to it.
Back to the original post, not sure if this is really your problem but it would be something you want to do anyhow.
Brent
The next step is what I'm going to do, use an rpm activated switch and module ($90) not including a 12v solenoid NC switch (can use the one from your A/C) to enrich by RPM (around 5k) so you can get the most fuel possible up top without running too rich down low. Here you would need to customize your enrichment setting to around 2.4bar like Lee does. This application would be used for 400+rwhp 930's only. Only at this enrichment will you max out the fuel pin or close to it.
Back to the original post, not sure if this is really your problem but it would be something you want to do anyhow.
Brent
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Sameer - if you want to see what this mod does to the A/F ratio, check out my post here:
https://rennlist.com/forums/showthre...threadid=90105
https://rennlist.com/forums/showthre...threadid=90105
#13
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Bill,
I've still not got my digital camera BUT BUT I just went for this Porsche club dinner on Thursday and we were lucky enough to have this professional photographer whom I managed to grab hold of to take pics of my ride. He will be passing it onto cd to me of which than I will be posting it.
I've still not got my digital camera BUT BUT I just went for this Porsche club dinner on Thursday and we were lucky enough to have this professional photographer whom I managed to grab hold of to take pics of my ride. He will be passing it onto cd to me of which than I will be posting it.
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#14
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Just a thought. When I had my 88 turbos, I would wait for the fuel pumps to get up to pressure before cranking the engine, becasue some of the lines run close to warm engine parts. I would try this first as it won't cost you anything.
#15
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Sammer,
It you do the head upgrade it does automaticaly enrich as air flow increased. This is why Brent delays his stock wur's enricment function.
I think you have the Andial fueler. I'd try adding the rpm switch that brent added but wire it inline with the boost switch that came with you Andial so you delay when it come in till much latter or you will bo way to fat to soon.
This way you will onely get the Andial enrichment on boost and after the rpm you select.
Just a thought.
Keith
It you do the head upgrade it does automaticaly enrich as air flow increased. This is why Brent delays his stock wur's enricment function.
I think you have the Andial fueler. I'd try adding the rpm switch that brent added but wire it inline with the boost switch that came with you Andial so you delay when it come in till much latter or you will bo way to fat to soon.
This way you will onely get the Andial enrichment on boost and after the rpm you select.
Just a thought.
Keith