Josh '88 Posted May 21, 2012 Report Share Posted May 21, 2012 My red '88 runs great when my boost controller is set at 10-12psi and below, I'd like to run my 14G to 15psi but the car will not run right. I recently replaced the plugs, wires, cap, and rotor button, no fix. I've got a fuel filter ordered and it'll be here tomorrow, but I'm not sure if that's the cause. Right now at full throttle, my wideband reads in the low-mid 10 range. The car's fuel filter has about 30k miles on it, so it needs replaced anyway. If that's not the fix, what else could it possibly be? Josh Link to comment Share on other sites More sharing options...
Dred_85.5_TSI Posted May 21, 2012 Report Share Posted May 21, 2012 too rich? maybe a leaking injector? under boost it can be in the 11s easily. Link to comment Share on other sites More sharing options...
rcm Posted May 21, 2012 Report Share Posted May 21, 2012 whats the fuel pressure reading?The pump maybe losing pressure after 11-12 psi. Link to comment Share on other sites More sharing options...
ESIrType? Posted May 21, 2012 Report Share Posted May 21, 2012 too rich? maybe a leaking injector? under boost it can be in the 11s easily. I had the exact same problem years ago. With the bigger exhaust I was boosting at 10psi and it ran like crap. I spent months to trace down a bad secondary injector, which a board member said to check from the beginning. Try swapping out your secondary. Shawn Link to comment Share on other sites More sharing options...
NotStock88 Posted May 21, 2012 Report Share Posted May 21, 2012 Why would you think the car is not getting enough fuel?Do you know how to read/understand the wideband read-outs properly (sounds dumb but its a legit question)?What kinda wideband do you have and where is the bung located that you have it screwed in to?What kinda manual boost controller?What fuel pump/injectors are you running?what is your timing set at?what vacuum lines have you replaced? If you are seeing 10's at wot you are running too rich. You really need to be sure the fuel system up to par and running properly, before you start upping the boost. You are heading in the right direction with getting the WBO2 Link to comment Share on other sites More sharing options...
CaliConquestAlex Posted May 21, 2012 Report Share Posted May 21, 2012 What about fuel cut on the stock ECU? On my old '87 flatty I did experience fuel cut a few times and it bucked like it wasn't running right. I lowered the MBC and it ran strong. Link to comment Share on other sites More sharing options...
Josh '88 Posted May 22, 2012 Author Report Share Posted May 22, 2012 (edited) I don't know what my fuel pressure is, I don't have a fuel pressure gauge installed on my car.It's just a guess that my car's not getting enough fuel. It might be the other way around, I could be over-riching the car.My wideband is a AEM UEGO, the O2 bung is installed about 3 feet past the turbo. Yep, I understand it's readings, 10.0 = super rich, 14.0 = stoich, 17.0 = super leanI'm pretty sure I bought the mbc from a member on here. I want to say that he made a few and sold them here, and all the buyers were pleased with them at the time.My fuel pump and injectors are stock as far as I know. I've owned the car since 2001, and have never replaced them or had trouble from them.The last time I checked my timing, it was 10deg BTDC, like the manual recommends. I'll recheck it asap.I have replaced all the vacuum lines with silicones, and I have 3. 1 for the vacuum advance, 1 for my mechanical boost gauge, and 1 for the dash vent solenoids.I highly doubt that I should be having fuel cut problems. Back in 2006, I was running a MAF Translator setup, and 18PSI on my 14G, wideband readings were 13.0 at idle, 12.0 mid throttle, and 11.0 full throttle. About 2 years ago, my translator quit working for some reason, so I just went back to a stock MAS, and I had to lower the boost. Now I'm wanting to finally figure out what's been causing this problem. Edited May 22, 2012 by Josh '88 Link to comment Share on other sites More sharing options...
CaliConquestAlex Posted May 22, 2012 Report Share Posted May 22, 2012 It could be fuel cut because you are using the stock MAS setup. No matter how much fuel you have... The computer will not let you boost past a certain psi without bypassing the fuel cut. I could be wrong tho... Link to comment Share on other sites More sharing options...
Skullzaflare Posted May 22, 2012 Report Share Posted May 22, 2012 It could be fuel cut because you are using the stock MAS setup. No matter how much fuel you have... The computer will not let you boost past a certain psi without bypassing the fuel cut. I could be wrong tho... this is the problem, another reason why many put a 1g maf on the cars, do bypass it, though some cars it just raises it to 14-16psiid recommend fixing or replacing the old maft, you have no way to control fuel right now, not sure how its running so rich too out of curiosity, what spark plugs did you install? Link to comment Share on other sites More sharing options...
Couth'nize Posted May 22, 2012 Report Share Posted May 22, 2012 I say it's the either the stock MAS or the injector. Let me know when you are ready to Megasquirt that thing. Link to comment Share on other sites More sharing options...
Josh '88 Posted May 23, 2012 Author Report Share Posted May 23, 2012 (edited) Hmmm.....I wasn't aware that the 88-89 ECU's had a fuel cut. At what psi does it kick in?I installed NGK spark plugs, I got whatever Advance Auto had listed for the Quest. Today, I installed my "old" translator setup, to see if I could troubleshoot it. It seemed to work properly, the only concern was it would lean out when under 1/4 throttle. I was able to get it tuned to 11.0 at full throttle without the MBC. I then installed the MBC and tried to tune it to 15psi, and it gave me the same trouble as before. I installed a new set of Trilogy Turbo OEM-spec injectors that I've had for a few years now, still no fix. My next plans is to check the ignition timing, and try out 2 other spare GM MAF's that I have. Edited May 23, 2012 by Josh '88 Link to comment Share on other sites More sharing options...
Skullzaflare Posted May 23, 2012 Report Share Posted May 23, 2012 (edited) Hmmm.....I wasn't aware that the 88-89 ECU's had a fuel cut. At what psi does it kick in?I installed NGK spark plugs, I got whatever Advance Auto had listed for the Quest. Today, I installed my "old" translator setup, to see if I could troubleshoot it. It seemed to work properly, the only concern was it would lean out when under 1/4 throttle. I was able to get it tuned to 11.0 at full throttle without the MBC. I then installed the MBC and tried to tune it to 15psi, and it gave me the same trouble as before. I installed a new set of Trilogy Turbo OEM-spec injectors that I've had for a few years now, still no fix. My next plans is to check the ignition timing, and try out 2 other spare GM MAF's that I have.the ecu does not, again, its the MAF sensor that is the fuel cutthey go off the frequency of the air (air vibrations), at a certain point it becomes unstable and confuses the ecu(if i remember correctly) Edited May 23, 2012 by Skullzaflare Link to comment Share on other sites More sharing options...
Starfighterpilot Posted May 23, 2012 Report Share Posted May 23, 2012 What gap do you have your spark plugs set at? You could be experiencing spark blow out if it's set too wide. Try dropping the gap back to 0.034" and see what happens. No sputtering - then keep increasing the gap by a 0.001" until you get blow out then drop back 0.001" t5o when you didn't have any. BTW what spark plugs are you running? That may also be the problem. They should be either NGK 7031's or BPR-7ES. Eliminate the simple stuff first before you start modifying or start spending bucks. For What It's Worth. KEN Link to comment Share on other sites More sharing options...
Caliber308 Posted May 23, 2012 Report Share Posted May 23, 2012 (edited) At 10.0 AFR on boost. I'd say your secondary Fuel Injector is stuck wide open. That will cause it to be super rich at WOT. At a Idle, take your car up to 3000 rpms. What is your Wideband AFR reading? Bill Edited May 23, 2012 by Caliber308 Link to comment Share on other sites More sharing options...
Josh '88 Posted May 24, 2012 Author Report Share Posted May 24, 2012 (edited) I worked on my car some today. The timing is still showing 10deg BTDC, and I currently got the car running great, tuned to the low 11's on the wideband, running the Translator, and the mbc at 12psi. I still don't know why my car acts up with the translator over 12psi. My plugs are either BPR6ES or BPR6EY, gapped to manual specs (.039-.043). When the car is sitting still and I take the car to 3k rpms, the wideband is bouncing back and forth around the high 14.0's, just like it reads when cruising. Edited May 24, 2012 by Josh '88 Link to comment Share on other sites More sharing options...
Josh '88 Posted May 26, 2012 Author Report Share Posted May 26, 2012 I took the spark plugs out of my car, they are BPR6EY11, gapped at .041. I'm gonna buy some NGK 7031 (BUR7EA-11) or BPR-7ES plugs and gap them at .034 and see what that does. Link to comment Share on other sites More sharing options...
Caliber308 Posted May 26, 2012 Report Share Posted May 26, 2012 I took the spark plugs out of my car, they are BPR6EY11, gapped at .041. I'm gonna buy some NGK 7031 (BUR7EA-11) or BPR-7ES plugs and gap them at .034 and see what that does. Not a bad idea. Too wide of a spark plug gap, combined with high boost= flame out. Link to comment Share on other sites More sharing options...
Josh '88 Posted May 27, 2012 Author Report Share Posted May 27, 2012 I had to order the plugs, none of my local auto parts had them in stock. I ordered 7031's, they'll be here Wednesday. Link to comment Share on other sites More sharing options...
Josh '88 Posted June 1, 2012 Author Report Share Posted June 1, 2012 I'm pleased to say that my car's fixed, it was the spark plugs. I got the 7031's (gapped @ .034) put in, and my car runs PERFECT! It's a fact that you'll always learn something new about these cars, no matter how long you've owned them. I'm currently running 17-18PSI of boost, low 11's on the wideband @ WOT, and it's amazing on how hard it pulls! Thanks everyone for your input/help. Link to comment Share on other sites More sharing options...
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