car runs rich on bottom and REALLY lean on top

[lore2486]

ok I've had this issue science i bought the car and have been trying to diagnose ever since. the car is a little rich in the bottom (under 4k) but that docent bother me i can adjust it via the chip. the real problem is over 6k where the car just dosent want to rev higher and my AFR jumps from 14.1 to 18 with is very lean. i was looking at the fuel pumps and i found my helper pump had a broken ground so i replaced it with an in tank walbro 255lph this made my car more stable AFR under 4k but it still docent fix the problem over 6k. i have new injectors coming in tomorrow (300cc/min volvo tubo) but i don't know what else could my problem be.... and without S14.net i feel helpless. any ideas on what else can cause a lean condition over 6k?

[valleymotorwerks]

Why are you throwing parts at the problem and not good solid troubleshooting? What's your fuel pressure like throughout the rev range? Start with that and see where t takes you... if you've good stable pressure above 6k then try cleaning your injectors. I am assuming a stock engine etc.

[lore2486]

yeah engine is stock, i am not really throwing parts. the in tank pump was dead so i replaced it. i also got a fuel filter as maintenance. and i order the injectors as an upgrade for future mods. i will try and hook up a FP gauge tomorrow to see how the pressure is throughout the band. thanks for the reply

[lore2486]

update:
i was trying to make the car run riched by placing the FQS to pos 2 wich adds 10% more fuel throught the map. the car has better AFR's throught but i still cant rev past 6k at full throtle. when you are at 5800 AFR's are 12.4-12.9 but when i hit 6k it jumps to 14.5-14.9 and just stays there. so now i dont know if its a ECU problem instead of a fuel one.... any ideas?

also i installe the new injectors but the car would not start with them. aparently they are bad or something. i tested them and they all click when applied 12v i have not read the coil impedance. i am debating sending them to get rebuild.

[e30s50dan]

If you do,try witchhunter.com...he will clean them and get them back to you in a day.$20 each..I was very happy with the results

[valleymotorwerks]

Get the original injectors back in the car and get a FP reading. Stop changing things, you're introducing changes for no reason

[lore2486]

Get the original injectors back in the car and get a FP reading. Stop changing things, you're introducing changes for no reason

they are back in the car, i am hooking up a fuel pressure gauge tomorrow.

[valleymotorwerks]

they are back in the car, i am hooking up a fuel pressure gauge tomorrow.

The best thing to do is to gather information before introducing changes. It's good tteh car is stoock since all the operating parameters are "knowns" and easilt verified.

[ForcedFirebird]

OK we at WOT-Tech found out what the problem was. His intake boot was collapsing under load just like this...

http://www.s14.net/forums/showthread.php?54966-Help-needed-for-running-issue!!&highlight=will+not+rev+past+6k

So now the lore2486 is happy and the car runs great!