Randall Posted February 25, 2013 Author Share Posted February 25, 2013 Yeah finally remote mounted my fuel pressure gauge so I could see it while driving. I get about 35 at idle and as the rpms go up the pressure just keeps dropping. Once it hits 20 the car leans out and won't drive. Tried two different fpr's and got the same result. Could this walbro 255 lph be a piece of junk out of the box? I pulled my tank and cleaned and coated it when I did my N/A weber motor build and that car would rev to 6 or 7 grand and still have plenty of fuel so I don't suspect blockage in the tank. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted February 25, 2013 Share Posted February 25, 2013 The pump could be junk. Where is it mounted? Is it as close to the tank as possible and as low as the bottom of the tank? Quote Link to comment Share on other sites More sharing options...
Randall Posted February 26, 2013 Author Share Posted February 26, 2013 (edited) It's mounted almost exactly like the stock pump from 76. Except it is a little above halfway on the tank and the pre filter hangs down to the bottom of the tank http://forums.hybridz.org/topic/96315-por-15-fuel-tank-repair-question/ I think this is what happened to my tank.... Edited February 26, 2013 by Randall Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted February 26, 2013 Share Posted February 26, 2013 (edited) Here is the common diagnosis that I use on diesel engines. It will work your gas engine also. Install a vacuum gauge inline before the fuel pump. Vac should be 1-4" with the pump running. Too high vac means a restriction. If the vac is very low pinch off the hose before the gauge and make sure the vacuum rises. This ensures the pump is pulling. You can also install a piece of clear acrylic hose before the pump to see if the pump is pulling in air bubbles. Edited February 26, 2013 by skirkland1980 Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted February 26, 2013 Share Posted February 26, 2013 I showed this to a former coworker (mechanic). He spent several hours trying to figure out the problem. Pump was running, vacuum was low but there was no fuel pressure. I finally went over to see what was taking so long. He showed me that everything checked out and I heard a gurgling sound from inside the tank....the truck was out of fuel. Quote Link to comment Share on other sites More sharing options...
Randall Posted February 26, 2013 Author Share Posted February 26, 2013 (edited) Well I got a vacuum gauge and some tees along with some clear fuel line. Car off pump running I'm getting 12 in of vacuum also there is a lot of air in the line. Edited February 27, 2013 by Randall Quote Link to comment Share on other sites More sharing options...
Randall Posted February 27, 2013 Author Share Posted February 27, 2013 (edited) well finally got into it... the 3/8 fuel hose i bought from autozone to connect the fuel pump to the tank had an inside liner that was peeling off restricting flow. Put new hose in and if pulls hard at about a High 12 low 13 AFR. I am basically running Cygnus's tune unchanged except the idle as his was quite rich around idle. What is the consensus on the best AFR under boost for this motor? PS. need to get new tires on my 15x7 wheels. The 195's cant hold traction in first our second when in boost. Edited February 27, 2013 by Randall Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted February 27, 2013 Share Posted February 27, 2013 I'm using that fuel line on my injectors. I hope mine don't peel off. 11.5:1 AFR is was most say is best under boost. Quote Link to comment Share on other sites More sharing options...
Randall Posted February 28, 2013 Author Share Posted February 28, 2013 Hmm I have it running around there now but it doesn't feel like it did in the 12's Quote Link to comment Share on other sites More sharing options...
loy Posted February 28, 2013 Share Posted February 28, 2013 I'd keep it in the 12s. 11 seems a bit rich. Quote Link to comment Share on other sites More sharing options...
Randall Posted February 28, 2013 Author Share Posted February 28, 2013 Yeah I have it at 12.8 at 7lbs and I can't keep traction in first or second on brand new 195 tires. Time to upgrade to 225's all around. Only thing that is still buggy is megasquirt will cut out randomly and I believe that it is because I am getting random voltage spikes as high as 18v Also I have KnocksenseMS and when I enable knock retard in MS and go back and look at the logs it's pulling timing everywhere randomly and the knock light on the sensor unit does not even flash. Quote Link to comment Share on other sites More sharing options...
Randall Posted March 1, 2013 Author Share Posted March 1, 2013 So i found this... http://forums.hybridz.org/topic/100926-major-voltage-spikes-and-sags-with-megasquirt-ii-30/ looks like im not the only one with voltage spikes. Also i was just doing some reading and saw that people recommended a stage 3 turbine when using the larger 50, 57, and 60 trim compressors. My setup has the T04e with a 50 trim and im still rocking the stock T3 and stock turbine. I am only running stock boost but i have positive pressure just about 2800 and 7lbs of boost by 3000. So im not understanding why some people say the stage 3 is necessary for the larger wheels unless it becomes a problem at higher boost levels Quote Link to comment Share on other sites More sharing options...
Randall Posted March 7, 2013 Author Share Posted March 7, 2013 alright well i added a 47uF 35v cap to the H1 position and im getting a constant battV in the data log. no only problem is very rarely ill see a rpm spike all the way to 6000 rpm... Also i built a manual boost controller using about 12 dollars worth of parts and tested out 10lbs of boost. Do any of ya'll with the vr sensor have random rpm spikes? Also what would be the maximum amount of boost I could run with a hybrid turbo and no intercooler? At 10lbs the datalog showed a MAT of 146 degrees at 4500 RPM Quote Link to comment Share on other sites More sharing options...
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