ok so i got brand new delphi 550 injectors and a lexus afm....put them in and now car studders under WOT after 5k extremely bad and coming up to 5k it feels as if its almost pulling timing but it doesnt do it nearly as bad at half throttle pulls harder also...it did not do this with the 440's and stock maf ...what is goin on? a/f is fine also im completely lost never did this before i have gone through everything....coils wires plugs etc..plugs are at .27 bcpr7es.. and at same boost as old setup...13lbs could it be injectors? they were flow tested and all and worked fine?! please any input is appreciated this started after the injectors and afm never hapened before
studdering at 5k rpms and above
- Thread starter 87supraboostin
- Start date
10.5-11 usualy....me and adjuster have been trying to diagnose but im not seeming to come up with anything...would the tps have an effect if not exact? what i dont get is this did not happen before the injectors and afm....
Adjuster
Supramania Contributor
He's tried the AFM's, both sensors and stuff like that.
I've suggested checking the ground to the coils, and sending JetJock a PM for ideas.
I'm tapped out, and can not figure out what's up. From what he's telling me, he just changed out the injectors, and the AFM to a Lexus sized one. (From a guy who was running it on another 87, so the sensor in the housing is the right one.)
He also can't get more than about 3 volts on the VF even with the fuel pressure adjusted all the way down. (With vac line off and plugged of course.)
Tried that first. Setting the base FP, but no joy.
Any ideas?
One more thing, The TPS has been changed, and adjusted, but it's not to TSRM specs from what I understand. (Mine is not "perfect" either, but it was the way my car ran best for some reason.)
Would the TPS cause this? His idle speed is just about perfect too.
Car runs fine, and makes power under 5k, but at WOT, and above 5k, it loses power/tune.
I've suggested checking the ground to the coils, and sending JetJock a PM for ideas.
I'm tapped out, and can not figure out what's up. From what he's telling me, he just changed out the injectors, and the AFM to a Lexus sized one. (From a guy who was running it on another 87, so the sensor in the housing is the right one.)
He also can't get more than about 3 volts on the VF even with the fuel pressure adjusted all the way down. (With vac line off and plugged of course.)
Tried that first. Setting the base FP, but no joy.
Any ideas?
One more thing, The TPS has been changed, and adjusted, but it's not to TSRM specs from what I understand. (Mine is not "perfect" either, but it was the way my car ran best for some reason.)
Would the TPS cause this? His idle speed is just about perfect too.
Car runs fine, and makes power under 5k, but at WOT, and above 5k, it loses power/tune.
What is fuel pressure or pump current when this happens? Put another way does it still do it with FP and B+ jumpered? Any aftermarket electronics on the engine? I doubt it's the TPS but what is it's voltage at WOT? Codes?
you know what i backed out on the afc and it pretty much went away...to much fuel? what the hell lol sometimes i wonder about my relationship with my car ,,,,and jetjock im kinda lost there sorry im putting in my new wideband monday,,,,that was on a friends and i think his has some issues no codes and voltage at what? sorry i have to be positive for myself 
i doubt the tps would do that too. sense you're doing everything already i would switch back to stock injectors and see if the problem goes away. maybe its too much fuel up top and its fouling the plugs??
i know guys have always done this combo setup and has had no problem, but cant say everyone is exactly the same.
i know guys have always done this combo setup and has had no problem, but cant say everyone is exactly the same.