fuel pressure-cold start?
#1
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i checked the fuel pressure on the cossie at the weekend, and since fitting the grp a pump it was slightly high, so i adjusted it down to 3.5 bar with the pipe off, and all round the car drives better than before, fuel economy is better, the problem is now the car doesnt start crisply like it did before , it fluffs the first crank and starts the second time perfectly.
Stage 3 closed loop, 7.2:1,
Any ideas?????
Stage 3 closed loop, 7.2:1,
Any ideas?????
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#2
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Firstly fitting a new fuel pump shouldn't have altered your fuel pressure after the reg....
not sure on why it struggles to start though, faulty temp sensor could be the problem though
not sure on why it struggles to start though, faulty temp sensor could be the problem though
#6
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maybe its always been high then? the pump has been on for a week before i checked the pressure, and it was all fine untill i lowered the pressure to what it should be, it drives soo much better now and is 30-40 miles per tank better on fuel so i dont want to raise the pressure again. its set at what it should now so i cant work out why i have a problem, the pump primes up on ignition as it should do etc...
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#10
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i checked the pressure with the engine hot, and the idle at 900rpm... just wondering now if the pressure would be lower with the engine cold maybe thats why?
or maybe i get more or less vaccum at the reg which changes the pressure?
Its only when i start from cold this problem happens ,once its warm its starts first time again
or maybe i get more or less vaccum at the reg which changes the pressure?
Its only when i start from cold this problem happens ,once its warm its starts first time again
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#11
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See how you get on with it, if you are confident that your sensors etc are all sound and a simple fuel pressure increase definately eradicates it, then i can increase the fuelling in your software for the first 250crank revolutions after ignition. That will normally fix this issue.
#15
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Originally Posted by JTECHSAFF
naaa its only ten mins at warp speed, i have six weeks off , so nows the time for me to bring it up, could you do it in a day so i can drive home same day? How much ![Surprised](https://passionford.com/forum/images/smilies/bigcry.gif)
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Details of what you get are here:
http://www.motorsport-developments.c...ginetuning.htm
If teh software is mine, and i change the crank fuelling tables, then that mod is FOC.
Same day is no problem at all.
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