Ryan.G Posted December 26, 2007 Share Posted December 26, 2007 Really feel for you with this problem darren I have cancelled the dyno Mapping now chap. Glad that we left it after having a play with the cruise map, as i was wondering how much it would change with more heat and seems like it was alot Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 26, 2007 Author Share Posted December 26, 2007 1/ Where abouts is the vacuum/pressure feed for the FPR taken from? 2/ Where is the FPR mounted (ie it could be to close to a heat source and this is causing the fluctuation) For question 2, the FPR is mounted at far right corner of the engine bay, as viewed from the front of the car. (I think this is where you would normally find the charcoal canister?) Do FPRs normally get hot? Is this known to be an issue? For question 1, if I understand the question right, there is a vacuum line from the throttle/map sensor. (Hopefully Darryl or Ryan can confirm this.) This was originally a poor quality silicon hose, but it's been replaced with a much sturdier one. Electronic gauge, petrol source in the cabin? Well, I don't know what this entails, but I guess someone like Mark at Phoenix might be able to sort something out for me. I havent read the whole thread but I am guessing you have already measured for constant voltage to the pump, how is the pump wired, are you still using the fuel pump controller? Is it possible to run the pump in diag mode, ie constant 12v? I haven't measured the voltage, no. Sorry, I dont have the equipment to do this, and I wouldn't know where to begin. As far as I know, the pump is wired in a completely standard manner. The only change is that it's a Walbro. I have run the pump in diag mode, by bridging the ports with the engine off and the ignition on. The pressure appears to stay constant for the duration of the observation (i.e. a few minutes), but I have to admit that I haven't (since replacing all the kit) done a before and after test once the FPR has heated up. I guess what I should do is check the pressure, drive the car for an hour, then check it again. Thanks for your help everyone. I'm feeling slightly reassured that we'll get there in the end! Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 27, 2007 Share Posted December 27, 2007 OK first off providing the vac hose is in good condition, the pressure/vac reference on the plenum may be taken from one of two places, depending on who plumbed it in, one is damped (a small cylinder screwed into the plenum next to the MAP sensor) and the other a straight outlet, it may be worth changing it from whatever it is currently plumbed into to the other, just to check. The location of the FPR should not cause any problems, the engine bay temps get to about 50C so don't normally cause any problems. Quote Link to comment Share on other sites More sharing options...
Jspec Germany Posted December 27, 2007 Share Posted December 27, 2007 Don't mean to interupt the excellent troubleshooting assistance being provided. Just wanted to say that it's been an interesting read and I hope it's sorted soon so you can enjoy your car. Keep the faith. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 27, 2007 Author Share Posted December 27, 2007 OK first off providing the vac hose is in good condition, the pressure/vac reference on the plenum may be taken from one of two places, depending on who plumbed it in, one is damped (a small cylinder screwed into the plenum next to the MAP sensor) and the other a straight outlet, it may be worth changing it from whatever it is currently plumbed into to the other, just to check. The location of the FPR should not cause any problems, the engine bay temps get to about 50C so don't normally cause any problems. Thanks Tricky. If I'm reading this right, I think it's actually plugged into both outlets, via a T-piece. One goes straight into a plastic fitting (the map sensor?) and the other goes into an outlet just below. They meet at a T-piece which then goes off to the FPR. I guess I could disconnect it so that it's only attached to one of these outlets? But I'm led to believe the map sensor definitely needs this feed, and I don't know what the other outlet does. Also, Ryan was measuring air temps reaching over 80 degrees, but he didn't suggest that was particularly hot? Quote Link to comment Share on other sites More sharing options...
TLicense Posted December 27, 2007 Share Posted December 27, 2007 Dash, I have an almost similar strange thing happen, in that when my inlet temps get hot, I have to add more fuel. I've got an AEM pressure sensor plumbed into my Aeromotive FPR and the fuel pressure is logged but isn't changing so I'm fairly sure it's not the FPR giving me problems. You mention you've got 800cc injectors. What make? I've got 870 Siemens. I take it 80degs was when sat still after a while otherwise yes, that's quite hot! There's quite a bit in the service manual about diagnosing fuel pressure related problems. Do you have access to a copy? If not I'll post it up after work. Cheers, Tony Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted December 27, 2007 Share Posted December 27, 2007 Thanks Tricky. If I'm reading this right, I think it's actually plugged into both outlets, via a T-piece. One goes straight into a plastic fitting (the map sensor?) and the other goes into an outlet just below. They meet at a T-piece which then goes off to the FPR. I guess I could disconnect it so that it's only attached to one of these outlets? But I'm led to believe the map sensor definitely needs this feed, and I don't know what the other outlet does. The feed for the Map sensor and the FPR on your Car Darren is taking from the Filtered outlet. (Stops any moisture or crap getting into the map sensor and FPR) The straight outlet feeds your Boost gauge and the Boost controller. Also, Ryan was measuring air temps reaching over 80 degrees, but he didn't suggest that was particularly hot? I think you were looking at the Water temps darren Your air temps cruising around were around 30c and then when the engine was turned off they rose to around 50-60c when the intake manifold heat soaked Ryan. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 27, 2007 Share Posted December 27, 2007 Try monitoring the voltages at the fuel pump terminals and see if they are changing. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 27, 2007 Author Share Posted December 27, 2007 Try monitoring the voltages at the fuel pump terminals and see if they are changing. I would if I knew how. I've just measured the fuel pressure at constant 12V with the engine turned off, after driving for an hour. It was about 6psi lower than when the engine was cold, but was slowly increasing as the unit cooled off. When I felt the FPR after getting out the car (after an hour of driving), it was a little warm, but no way near as hot as it was when I did the same thing yesterday, and the car was going no way near as lean today either. I dont know why it heated up so much more yesterday. The weather didn't seem any warmer yesterday. I've had a look at the vacuum lines, but I really can't make sense of what I need to do, in terms of attaching it to different outlets. I would take a picture, but I'm away from home and dont have the facilities. Can anyone recommend any one person who would have the skills to diagnose and resolve this for me? I'm hoping for someone in the London area or south. (I live in Berkshire, but as I type I'm in Somerset.) I guess I could travel further, but the longer I drive, the leaner it goes, and I worry about the damage I'm doing to the car. I'm ashamed to say I'm not too good at working with cars. Changing sparks and swapping the Aeromotive is about as hands-on as it gets for me! In the meantime, I'll get the stock FPR fitted, in the hopes that I've been unlucky enough to have fitted two defective Aeromotive units. (I'm told the odds of this are pretty astronomical.) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 27, 2007 Share Posted December 27, 2007 In tank fuel pumps use the fuel flowing over and around the workings of the motor to cool it, so in use they inevitably raise the fuel temperature a bit. It shouldn't raise it much though. The FPR won't raise the temp a noticeable amount in itself. If the pump is getting a low voltage to its terminals it may run hotter, and thus raise the fuel temp more. After market FPR's often show temperature instability, I maintain you should get the voltage at the pump terminals tested, and to fit a totally stock FPR. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 27, 2007 Author Share Posted December 27, 2007 Then that is exactly what I shall do. I realise you said to put in the stock FPR all along, but I couldn't find anyone who was able to fit it, and I was reluctant to leave it too long, given the car is my daily driver. Thanks for explaining how the pump can raise the temperature of the fuel and, consequently, the FPR. This is looking more and more like a possibility. Something is causing that FPR to become so hot, it's almost too hot to touch. Quote Link to comment Share on other sites More sharing options...
AndyT Posted December 27, 2007 Share Posted December 27, 2007 I would if I knew how. I've just measured the fuel pressure at constant 12V with the engine turned off, after driving for an hour. It was about 6psi lower than when the engine was cold, but was slowly increasing as the unit cooled off. When I felt the FPR after getting out the car (after an hour of driving), it was a little warm, but no way near as hot as it was when I did the same thing yesterday, and the car was going no way near as lean today either. I dont know why it heated up so much more yesterday. The weather didn't seem any warmer yesterday. I've had a look at the vacuum lines, but I really can't make sense of what I need to do, in terms of attaching it to different outlets. I would take a picture, but I'm away from home and dont have the facilities. Can anyone recommend any one person who would have the skills to diagnose and resolve this for me? I'm hoping for someone in the London area or south. (I live in Berkshire, but as I type I'm in Somerset.) I guess I could travel further, but the longer I drive, the leaner it goes, and I worry about the damage I'm doing to the car. I'm ashamed to say I'm not too good at working with cars. Changing sparks and swapping the Aeromotive is about as hands-on as it gets for me! In the meantime, I'll get the stock FPR fitted, in the hopes that I've been unlucky enough to have fitted two defective Aeromotive units. (I'm told the odds of this are pretty astronomical.) Matt, Muffleman, is going to be in business in or near Crawley 1st week in New year bud. Can't help personally though. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 27, 2007 Author Share Posted December 27, 2007 Thanks for explaining how the pump can raise the temperature of the fuel and, consequently, the FPR. This is looking more and more like a possibility. Something is causing that FPR to become so hot, it's almost too hot to touch. It just occurred to me that Darryl said the fuel pump was always noisy in this car. After we replaced the fuel pump, it was still noisy, so we didn't think much of it. If the pump wasn't getting a constant 12V supply, that might cause it to be noisy? I'm hoping that the light at the end of the tunnel might just be some re-wiring!! Quote Link to comment Share on other sites More sharing options...
b_have Posted December 27, 2007 Share Posted December 27, 2007 I would check the pump/wiring, My Walbro is only noisy under high load (with dirty sock filter). Check the temp of the fuel filter whilst running, that should NOT be warm if the pump is healthy. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 27, 2007 Author Share Posted December 27, 2007 I've just had a feel of the fuel filter (the one under the passenger seat) and it's cold! The engine is off, but I've been driving for about 30 minutes. I then felt the FPR and it's really hot! (Nearly as hot as the throttle body itself.) I felt the fuel hoses going to the FPR, and that was really hot too. Then I started the car (just a few minutes ago) and left it idling. What's interesting is that the fuel pipe feeding the FPR instantly went cool (I guess because the fuel running through it is cool), and the FPR is now cold! Also, when I started the engine, the fuel pressure was reading 24psi and now it's raised to 30. I think we now have overwhelming evidence that the FPR gets hot under load, and that this heat is causing it to drop pressure. But the FPR is not getting hot when the engine is idling, and the fuel filter doesn't appear to be getting hot at all. Do we still think the fuel pump/wiring is causing the problem, or does the cold filter rule this out? Maybe I need some cold air induction for my FPR!? I guess what I need to do is now give the car another run, get the FPR nice and hot, and then immediately have a feel of the fuel hose feeding the FPR to see if it's hot. I guess that would confirm that hot fuel is causing the problem. And, presumably, hot fuel certainly wont be doing the engine much good either. Thanks again to everyone for their input. I know this thread is getting lengthy. Quote Link to comment Share on other sites More sharing options...
AndyT Posted December 27, 2007 Share Posted December 27, 2007 Not at all. It's interesting and could be edited into a useful tech piece. We want to see your car sorted soonest and back running ok. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 27, 2007 Author Share Posted December 27, 2007 Thank you. That's why I love this place... The community spirit is fantastic. I owe you guys... Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted December 27, 2007 Author Share Posted December 27, 2007 Well done guys! I just felt the fuel filter again after a long drive and it was certainly rather warm! (I must have left it too long to cool down the first time.) So I think this further indicates the problem is at the fuel pump end, as it seems that warm/hot fuel is reaching the FPR. I can't measure the voltages myself, so I'll take it into a garage ASAP for them to look at it. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 27, 2007 Share Posted December 27, 2007 I think maybe there is too much emphasis being placed on fuel temp, however it cold have an impact on the actual FPR components perhaps, but fuel wise as the system is always pumping fuel, there is or should be a constant cooling effect, i am now starting to also think fuel pump, or a partial perhaps movable blockage somewhere in the fuel lines. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted January 8, 2008 Author Share Posted January 8, 2008 The car is going in to Phoenix tomorrow, where Mark and Matt H will be taking a good look at it. So after tomorrow, this will hopefully be resolved and I can finally drive my car the way it was meant to be driven. Quote Link to comment Share on other sites More sharing options...
Nic Posted January 8, 2008 Share Posted January 8, 2008 The car is going in to Phoenix tomorrow, where Mark and Matt H will be taking a good look at it. So after tomorrow, this will hopefully be resolved and I can finally drive my car the way it was meant to be driven. Good luck getting it sorted, you should have your new wheels to put on it very soon too. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted January 8, 2008 Author Share Posted January 8, 2008 Indeed, thank you! By the end of the week, I'm hoping it will look and go great! That's if I can actually source any Eagle F1s for it. They're prooving to be a bit of a problem. Quote Link to comment Share on other sites More sharing options...
dini_the_owl Posted January 8, 2008 Share Posted January 8, 2008 I havent read every thread here but are you using the stock fuel pump Pulsation dampener attached to your block? where have you mounted the fpr? one things for certain, it shouldnt get too hot to touch???? if your filter is cold and fpr is hot next thing in line back is the fuel dampener. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted January 8, 2008 Author Share Posted January 8, 2008 I've never even heard of a fuel pump pulsation dampener! Quote Link to comment Share on other sites More sharing options...
Homer Posted January 8, 2008 Share Posted January 8, 2008 It still has the stock pulsation dampner in place Quote Link to comment Share on other sites More sharing options...
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