heres the deal. I'm helping a buddy setup his turbo integra (92) and he's got the unit wired in and we're trying to setup the fuel curves. He used to be running an FMU, missing link, fpr, and so on to get the proper fuel. Then he had the bright idea to install 440-450cc injectors (with the in-line resistors). Car runs, but heres the problem. Everytime he gets into boost he throws a check engine light because the map sensor voltage is too high. If I'm correct in my thinking, anytime the MAP volts go into pressure the check engine light comes on. So we watched the map votls...and I'm right. Well, we tried putting the missing link (the fancy check valve deal) back inline to the map sensor and all is great, but since the afc adjusts the map voltage to change the fuel, anytime we try to bring fuel to the positive side of the curve it does nothing. What are we doing wrong? All the guys hes talked to said they're setting thier cars up on the negative side of the fuel curve and don't encounter this problem with the check engine light because there map sensor never sees that much voltage. But we have to increase to the positive side to get enough fuel to his car (.92-93 on his O2 sensor). Please help us figure this out. By the way he does have a high volume/pressure fuel pump run in-line with the stock pump. Thanks. And if it matters, hes only running 8psi of boost.

 

Do you know whats odd. We did a very similar setup in my friends D16z6 hatch, using 450cc dsm injectors and inline resistors, car ran fine, no problem. We are using a Fields Vtec controller for adjusting the fuel curve. (before hand he used this controller to ADD fuel with the stock injectors, and it also acted as a voltage clamp, so no check valves were used) So we go on our first test drive, and the CEL comes on.. Map code..? I thought that was very odd, so we boosted again.. and it kept going off? So I took out the multimeter and probed the input map wire to the ecu, and sure as ----, it went over 3.2v's when boost was hitting? But how in the ---- is that even possible since the fuel curve is in the Negitive area... at idle and normal load the voltage is set low, (like normal) but I have absoultly no clue why it does this! So we had to put some check valves on to keep the ****** off. I am still amazed, I need a bit more time to figure out what exactly is going on.. so your not the only one!

Jeff

 

Jeff,do you think it would be worth turning up the fuel pressure at idle? that way we could could bring the fuel maps down a few % and then we'd have room to mess with the fuel on the top end when he eventually decides to run more boost. I dunno...I'm begining to hate this afc...I thought it would help make things simpler but now its just causing more problems. I hate to raise the fuel pressure because we got the afc so we wouldn't have to be running insane fuel pressures (135psi). I'm open to any suggestions as both him and I are at a stand still on trying to tune his car. what kind of fuel pressures is everyone running that has the 450cc injectors with an afc?

 

Is the car running lean? how does it run?

I use normal fuel pressure 32psi

Jeff

 

the car runs pretty good, but I'd like to get the fuel a little richer when hes at 8 pounds. Oh, and we're running 50 pounds of fuel pressure at an idle....goes to 60 with the vaccum line off the regulator. I just don't understand why its not getting enought fuel. I'd think at 50psi of fuel, 0% fuel adjustment at WOT that we should be rich as hell. Do you think theres a glitch somewhere?