Muffleman Posted February 26, 2008 Share Posted February 26, 2008 Did Matt check for voltage variation over time to the pump? Don't know, you'd have to ask him. We had another Supra on the dyno just before Darren's, both cars had been sat in the same workshop overnight. One left no water on the dyno floor and only gave off the condensation I would expect from a Supra, the other left a mug full of water on the floor and the steam could be seen coming out of the extract fans out the back of the dyno. Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted February 27, 2008 Share Posted February 27, 2008 the other left a mug full of water on the floor and the steam could be seen coming out of the extract fans out the back of the dyno. Hmm strange one that, given the test results, long shot shot, running pressure triggered water injection with a fault by any chance. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 27, 2008 Share Posted February 27, 2008 Did Matt check for voltage variation over time to the pump? I believe Matt Harwood fully checked out the pump voltages under several conditions and confirmed everything to be in order. This is really odd, the car was running superb when Ryan mapped it last under my ownership and there was no sign of excess moisture from the exhaust at that time. The water getting to the exhaust has to be the key to the problems here - wouldn't that screw up the mapping, especially the water temp correction (i.e when it gets hot the wideband is reading lean so the map - based on the O2 readings - causes it to add in extra fuel where it's not needed? Hence drop in fuel pressure?) It has to be something fatigue related as the symptoms Darren explained appear to be getting worse Quote Link to comment Share on other sites More sharing options...
Homer Posted February 27, 2008 Share Posted February 27, 2008 Hmm strange one that, given the test results, long shot shot, running pressure triggered water injection with a fault by any chance. There's no WI Ricky Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 27, 2008 Share Posted February 27, 2008 Fuel pressure variations of the magnitude you talk of are nothing to do with head gaskets, coolant leaks, turbo water cooling or anything like that. have you put a stock FPR on it yet? Where is the vac / pressure signal taken from? Does it vary at idle with the vac signal hose disconnected? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted February 27, 2008 Share Posted February 27, 2008 I think all those checks have been covered a while back Chris, Homer, the WI bit was kind of in jest, but you never know until you ask;) Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted February 27, 2008 Author Share Posted February 27, 2008 What I'm a bit puzzled about is this... Given there was a 'mug full' of water behind the exhaust as Matt (Muffleman) described, how come the coolant level in the expansion tank doesn't appear to be going down at any significant rate? As mentioned, I've only had to top it up once in the last two months or so, and that was only by a couple of inches in the small expansion tank. Could the puddle be anything else but coolant? Quote Link to comment Share on other sites More sharing options...
Muffleman Posted February 27, 2008 Share Posted February 27, 2008 Fuel pressure variations of the magnitude you talk of are nothing to do with head gaskets, coolant leaks, turbo water cooling or anything like that. have you put a stock FPR on it yet? Where is the vac / pressure signal taken from? Does it vary at idle with the vac signal hose disconnected? Haven't tried a stock FPR yet Chris, the vac feed is taken from the inlet manifold on it's own line. It was a line taken that was feeding other things too, but we've isolated it now. When cold the pressure is nigh on 40psi at idle, when the problem appears and the pressure drops, at idle, disconnecting the vac hose restores the pressure. Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted February 27, 2008 Share Posted February 27, 2008 The water issue does seem very strange! I know that you have now checked the FPR feed + return lines however have you checked the line between the regulator and rail? Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted February 27, 2008 Author Share Posted February 27, 2008 Today the car was at Phoenix having some other work done by Mark and Matt Harwood. (I've had some RLTC issues too!) While it was there, the guys did the testing that Ian suggested earlier, i.e. venting the return line direct to a jerry can. This seemed fine, and as far as I'm aware, the fuel pressure before and after was the same. I guess this means the return line is okay. When they started the car up in the evening, a small puddle did form under the exhaust. However, Mark and Matt are both of the opinion that this fairly normal for a Supra. They tested the efflux and tell me there was no coolant in it. They are both convinced there is no head gasket problem or other coolant contamination issue. (This would tend to agree with the fact that my coolant level is pretty constant.) To answer Sean's question, I don't believe the line between the FPR and the rail has been checked, so I'll certainly put that on the list of things to try. Back to the stock FPR issue... the car has now had three Aeromotives fitted, one of them brand new and another a known-good unit from Terry. I can't believe that all three could be at fault!!? We haven't fitted a stock one, because we can't see if the fuel pressure is dropping on it. (No gauge...) Matt did mention that I should keep an eye on the boost gauge to confirm potential vacuum problems. I did notice that when coasting on minimal throttle (e.g. say at 60 in 6th), the boost pressure was reading more vacuum (i.e. more negative on the gauge) than when idle or with the clutch engaged. Is this normal? Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted February 27, 2008 Share Posted February 27, 2008 Yes boost/vacuum gauge will show more vacuum on over run, thats normal, so lets recap, fuel pump voltage monitored for a few mins while engine running? all fuel lines checked apart from the one from FPR to fuel rail? compression and leakdown checked and fine, coolant tested for combustion gas and is fine, There is one more test you could try just to get a bearing on whats going on with fuel pressure, and that is to supply a set and constant vacuum signal to the FPR to achieve a fuel pressure of say 40psi run engine and monitor the pressure, and AFRs, this will at least isolate the vacuum signal from the engine and eliminate that, and then point a finger at the FPR. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 27, 2008 Share Posted February 27, 2008 Just to add, the line between the rail and the fpr was replaced a couple of months before Darren bought it (The XS power one on there before perished). It was replaced with a standard rubber fuel line - however it's a simple and cheap thing to swap out again if only for elimination. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted February 27, 2008 Author Share Posted February 27, 2008 I've also noticed that when the AFRs start to go lean and I'm sat still (e.g. at the lights), the cabin starts to stink of fuel. It doesn't seem to smell while the AFRs are normal. Interesting point about that line being replaced Darryl. It's now top of my todo list! Tricky, everything you said was correct. The problem with the constant vacuum test you suggested is that the FPR/AFR problem does not manifest just on idle. You do have to drive the car first. I guess I can't really do that with constant vacuum signal to the FPR. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted February 27, 2008 Author Share Posted February 27, 2008 Darryl, when did you first notice the erratic AFRs when you had the car? I don't suppose it started when you changed that line between the FPR and the rail? It would be a mighty nice coincidence if it did. (But I seem to recall you saying the car had always had strange AFRs, presumed due to a bad wideband sensor?) Quote Link to comment Share on other sites More sharing options...
Homer Posted February 27, 2008 Share Posted February 27, 2008 Darryl, when did you first notice the erratic AFRs when you had the car? I don't suppose it started when you changed that line between the FPR and the rail? It would be a mighty nice coincidence if it did. (But I seem to recall you saying the car had always had strange AFRs, presumed due to a bad wideband sensor?) Yes, the AFR's were always a bit strange on idle (reading MUCH richer than it should have). After the "final" mapping session with Ryan everything pointed to a dodgy wideband sensor as it was not inline with the AFR's Ryan was getting on his gauge. I recall that since the sensor was replaced the gauge now matches Ryans one, so it's impossible to know whether the current problems were present before Sorry if you've already answered, but does the PFC flag up any det warnings on boost after it's starting the lean idle thing? It was always okay on boost and only occasionally flagged a det warning on VERY high load (This was in the middle of summer with high intake temps). Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted February 27, 2008 Share Posted February 27, 2008 If i was you i would pull the line between rail and FPR just to check it. Its not very long so just replace if with some rubber fuel rail from any motor-factors, should only cost a few quid too. While it was there, the guys did the testing that Ian suggested earlier, i.e. venting the return line direct to a jerry can. This seemed fine, and as far as I'm aware, the fuel pressure before and after was the same. I guess this means the return line is okay. If this is the case then doesnt this point to the problem being the return line? If the fault DIDNT occur when the return line wasnt used.... Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted February 27, 2008 Share Posted February 27, 2008 Have you monitored both the fuel pressure and AFRs when you get the fuel smell? and if so what are they? And you could drive whilst having the fuel pressure set as static provided that you don't achieve more that 6psi of boost, but you would need monitor AFRs closely. Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted February 27, 2008 Author Share Posted February 27, 2008 The AFRs are lean when it smells. But the fuel pressure is harder to monitor as I dont yet have a working fuel pressure gauge in the cabin (and I can't pop the hood while I'm waiting at the lights). I do have a gauge fitted, but it didn't have the right unions, so I have some parts to order... Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted April 2, 2008 Author Share Posted April 2, 2008 Well, some exciting news... I've finally got a load of gauges in the cabin and Mark at Phoenix has been playing with the car. It turns out that the fuel pressure is rock solid (even when the AFRs are lean) and does exactly what it's supposed to on boost. So it looks like there was no fuel pressure problem afterall! One of the other gauges I fitted was an oil temperature gauge. Mark tells me that the car goes lean when the oil temperature reaches above 70 degrees, which explains the symptoms and the circumstances under which the AFRs go lean. In particular, the AFRs go off the scale at 82 degrees. Mark has recommended that I get the car remapped using the oil temperature readings. (I think it was done using water temps before.) I'm not sure how easy it is to get the PowerFC to take an oil temperature feed, but I'll be speaking with Ryan about that in due course! Has anyone else mapped using oil temperature readings before? Is 82 degrees abnormally hot? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted April 2, 2008 Share Posted April 2, 2008 April the first was yesterday.... Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted April 2, 2008 Share Posted April 2, 2008 April the first was yesterday.... haha Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted April 2, 2008 Author Share Posted April 2, 2008 I had no idea I was being funny. Quote Link to comment Share on other sites More sharing options...
Sean1933 Posted April 2, 2008 Share Posted April 2, 2008 So did you actually fixed it in that case? I assumed it was a joke as i thought the map had been checked and it wasnt a factor, plus it was the 1st of April yesturday! Quote Link to comment Share on other sites More sharing options...
Dash Rendar Posted April 2, 2008 Author Share Posted April 2, 2008 No, it's not fixed. We've merely established the fuel pressure isn't dropping, and therefore isn't the cause. So we could try remapping... Or failing that, maybe the PowerFC is faulty. I thought early on that it might be the ECU, but when the gauge in the engine bay showed the fuel pressure dropping, I figured that had nothing to do with the ECU, since there's no way the ECU could do this. But now I know the fuel pressure isn't dropping, I'm having to rethink! Doh... Quote Link to comment Share on other sites More sharing options...
Ryan.G Posted April 2, 2008 Share Posted April 2, 2008 Well, some exciting news... I've finally got a load of gauges in the cabin and Mark at Phoenix has been playing with the car. It turns out that the fuel pressure is rock solid (even when the AFRs are lean) and does exactly what it's supposed to on boost. So it looks like there was no fuel pressure problem afterall! One of the other gauges I fitted was an oil temperature gauge. Mark tells me that the car goes lean when the oil temperature reaches above 70 degrees, which explains the symptoms and the circumstances under which the AFRs go lean. In particular, the AFRs go off the scale at 82 degrees. Mark has recommended that I get the car remapped using the oil temperature readings. (I think it was done using water temps before.) I'm not sure how easy it is to get the PowerFC to take an oil temperature feed, but I'll be speaking with Ryan about that in due course! Has anyone else mapped using oil temperature readings before? Is 82 degrees abnormally hot? Ok im confused lol Basically i cant see how the oil temps can effect the a/f and i think this is why others are making jokes. I have alot of respect for Marks work but just confused by when the oil temps go over 70c the fuel required is ALOT more as it doesn't just go slighty lean it goes off the scale. Now if it was say that when the water temps or air temps went over say 70c degrees it went lean then it could be due to the ecu or map as could have a bad checksum in the temp correction causing it to take away fuel but i have been over your map many times and after 50c temp there is no correction applied. Before 50c there is only fuel added. Having also checked your datalogs of when the problem occurs there is no change in the water temp or air temp. The only last thing i can think of is the battery voltage is dropping when the problem occurs and the injector battery offset for the injectors are wrong which cause it to remove fuel. Ryan Quote Link to comment Share on other sites More sharing options...
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