Paul83b

iTrader: (9)

my bugeye jdm sti was mapped this week,

first time it ran lean because of a fuel pump problem so i changed the pump for a walbro 255 unit, it started better in the morning and felt a much happier car.

then had it mapped again, it was fine, ran 1.4 / 1.3 bar safely with an AFR of 11 point somthing, which is where it should be.

put it on the rollers today for a power run and its running an AFR of 13 point something.

ive changed the fuel filter and FPR recently aswell, any other suggestions?? could do with some advice on what might be causing it please?

my94wrx

iTrader: (4)

who mapped the car? did you ask there opinion? what did the rolling road operator say?

did you change the FPR before or after mapping? was it a adjustable one? was it set to the same pressure?

have you checked the maf?

Paul83b

iTrader: (9)

richard o donovan, he's coming tomorrow to check it, which is good of him! hes rechecked his saved map data and says it was running 11 when it was mapped but hes gonna come back to check it anyway.

havent checked the maf but havent got any fault codes, changed the fpr before mapping as i had a fuelling issue before (only for another standard one that i had kicking around), then changed the fuel filter before changing the pump as i had to take my whole sound system install out to get to the pump. turned out the pump wasnt uprated to 255 like it should have been and was faulty which was causing a fuelling problem.

it used to struggle to start with the old pump on aswell and now its first time on the key. i thought that had solved the issue to be honest but obviously it hasnt.

rolling road operator said its running too lean and showed me on the print out then stopped the session, said to contact the mapper.

my94wrx

iTrader: (4)

who's richard o donovan? fair play for him coming to check it out, you don't need a error code for a MAF to be knackered, they fail gradually over time and catch you out.

Paul83b

iTrader: (9)

ill try a maf change 2moro and see if it changes anything, thanks. ive got a spare one kicking around somewhere

Paul83b

iTrader: (9)

changed the MAF, changed the MAP, checked the fuel pump control unit in the boot, checked all the wiring to the pump, tested all the voltages from the ecu and at the pump itself and theres no reason what so ever for it to occasionally run lean! its baffling me! the only other thing i can think is a bad earth or something but im never going to find that.

Rich came back at spent the whole day with me fault searching and weve now remapped the car again to compensate for the problem for now. top bloke, cant believe how good hes been to me. didnt charge me any more for the help yesterday either. so so impressed.

oh well ill give up on it for now