Technology Posted December 17, 2011 Report Share Posted December 17, 2011 What size T4/T3? and don't just give A/R ratios, that means nothing. what is the inlet size at the blades, in millimeters? the A/R of the exhaust means a lot though. You may just be running out of fuel at higher boost. 40psi fuel pressure is good, can you see what it's doing as the boost rises? if it starts falling off when you have problems, then you have a pump that's too small. Quote Link to comment Share on other sites More sharing options...
Indiana Posted December 17, 2011 Report Share Posted December 17, 2011 You using a stock fuel pressure regulator? How are you controlling boost? Quote Link to comment Share on other sites More sharing options...
dirtydevin Posted December 17, 2011 Author Report Share Posted December 17, 2011 Stock fuel pressure regulator, with walbro 255 pump.I can't see the fuel pressure guage under boost, but I think I will get a stainless braided line so I can hook the guage up so I can see it for diagnostics. Unfortunately I don't have all the info on the turbo, I think it is a ebay special 63 ar exhaust and 50compressor, I am controlling the boost with a regulator to the external wastegate. Quote Link to comment Share on other sites More sharing options...
Technology Posted December 18, 2011 Report Share Posted December 18, 2011 well, just take a caliper and measure the inlet of the compressor at the blades, that gives a decent idea of what you're working with. If all the electronics are working, and the fuel pressure isn't dying off because of a bad pump or kinked line (doubt that), then your injectors are too small, or it's knocking because of poor gas. The walbro 255 supports 450whp on E85, and like 650-700 on race gas. The pump probably isn't the issue. Quote Link to comment Share on other sites More sharing options...
Mike_StarionTSI Posted December 18, 2011 Report Share Posted December 18, 2011 Don't rule out the pump so quickly. It could be a faulty pump. It's most likely not the case, but always have that in mind. You just never know. Quote Link to comment Share on other sites More sharing options...
dirtydevin Posted December 21, 2011 Author Report Share Posted December 21, 2011 Well I finally got a code from the ecu after swapping back to a one wire o2 sensor, and I got code 3 for the mas. I know I was told not to upgrade the mas and maft until I got the problems figured out, but I hate to buy a stock mas just to have to go out and buy and buy another one with the maft. I suppose the best bet would be to try and find someone with a known good stock mas and swap it on my car for a test to see if that indeed solves my problems. Then if I know that is it I could go ahead and upgrade and tune it with the maft, to get it just right with the t3/t4 and higher boost. Quote Link to comment Share on other sites More sharing options...
pintos86quest Posted December 24, 2011 Report Share Posted December 24, 2011 does anybody have a pic they could post of the plugs on the coolant temp I'm dealing with the same problem i got a yellow w/green striped wire and don't see a black with yellow striped wire to put there mine is an 86 quest though. don't know if that makes a difference.thanks guys i would realy like to have a a running car for christmas. Quote Link to comment Share on other sites More sharing options...
Indiana Posted December 24, 2011 Report Share Posted December 24, 2011 (edited) This is from an 84 but for a few years there were two connectors for the gauge as described below. The CTS is the one with the molded boot over the connector and its usually cracked and in pieces or just missing and the plastic connector is there under it. You see the blue tape wrapped around an unused connector towards the bottom? If this were an automatic car then that connector would have been used and not the single wire temperature gauge unit plug that you see on the left. Both yellow striped wires in both temp. gauge unit connetors are the same its just the second wire is for the overdrive switch in the auto tranny wiring harness. http://a7.sphotos.ak.fbcdn.net/hphotos-ak-snc6/249651_1403264139807_1778479606_670389_4643724_n.jpg Edited December 24, 2011 by Indiana Quote Link to comment Share on other sites More sharing options...
Toddone Posted December 26, 2011 Report Share Posted December 26, 2011 IN my opinion I would set the gap on the plugs to .028. WIth the upgraded turbo you are prolly blowing the spark out or just leaning out. You said you had a bung welded in for a wide band. A fuel pressure gauge. The problem you described you are loosing spark or fuel. I had an issue once with a soft set connector on the secondary injector causing intermittant problems in boost. With the tools you already have you should be able to diagnose the problem pretty easily and stop throwing parts at it. Hookup wideband, and fuel pressure gauge. When vehicle starts to break up, notice the data. If widebands going lean and fuel pressure is stable then you know you are running out of fuel. If when breaking up the wideband goes rich you are loosing ignition. Hope this helps. Quote Link to comment Share on other sites More sharing options...
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