The Punisher 0 Posted June 18, 2007 Report Share Posted June 18, 2007 Right let me start at the start... give some back ground before explaining the problem. You may remember the car i have bulit was bulit purly for the drag scene so is diffrent to a standard VR in some ways. One being the fuel pump has been uprated to a high pressure electric inline pump, this runs independant to the ignition and in switched on when the engine fires. Switching it on before causes the engine to flood and not start (it never used too.) I have had warm running problems for a while and suspecting the FPR replaced that the flooding still occured and seems the warm running problems was still there. From cold the engine starts and will run at approx 800rpm for about 3-4min then the revs drop to 500rpm and the engine will quite happyly idle, rev smoothly and drive around for as long as you want. Cars needs minimal revs to pull away. Problems start when the car has been running for about 30 -40 mins when you stop the engine. You restart it and it fires up into life switch on the fuel pump and the engine dies, swicth on the fuel pump and keep you foot on the gas its it back fires, misses, black smoke and genrally runs terrible take your foot off the gas and it dies. Now if you can hold it there revving for long enough soon it calms down and will idle, but every time you go to rev the car the revs go to near stall before then revving freely. Putting the engine under load like this makes the engine stall easy like it has no torque increaseing the revs solves this. The problem has been getting worse and worse and worse. Ok so thats the problem here are a few obervation and thoughts i have already had. The spark plus are as black as the ace of spades, prelonged over fueling and long sessions just idleing and revving with no load. could be the reason for them being so black, and as a result not enough spark to ignite the fuel and also would get worse over time. i have not replaced spark plugs yet but im sure it will help if not solve the problem. Did give them a once over with a wire brush and for one warm start it did behave diffrently. Also when i go the engine the plugs were in good condition and the engine did not flood at start up. Thoughts about this threory?Does the VR6 have a choke? Increased rev for a few mins at the start of a cold indicates this and the choke tries to come in everytime its starts so the engine chokes and dies. Knackard Lamber probe how can i check?Any other ideas welcome anyone else had this probelm?Many ThanksJoel Link to post Share on other sites
gezza 0 Posted June 18, 2007 Report Share Posted June 18, 2007 what about an air leak some were casueing it to overfuel and hence the stalling when first revving?? you tried maf sensor?? sounds to me like that or just plain old vaccum leak?? either way somat to with air mixture. Link to post Share on other sites
The Punisher 0 Posted June 18, 2007 Author Report Share Posted June 18, 2007 Air leak has crossed my mind i have looked for one but couldnt find one or see one... might try washing up liquid. tell tale bubbles. Not tried MAF yet any way to check them?Joel Link to post Share on other sites
gezza 0 Posted June 18, 2007 Report Share Posted June 18, 2007 yeah get some one elses maf on yours and see if it cures it?? tbh if it is air leak it will suck the bubbles in unless of course its blowing em out??!!!! could well possibly be maf i have had 3 scoobys now and they are always mafs on them. not 100% sure on vr6 but wouldnt put it past it!!! its gotta be air i reckon just for the simple fact its over fueling ecu is trring to compensate for mixture?? Link to post Share on other sites
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