SR20DET Running Lean

[lourens13]

Did a search on the forums, found some similar problems, but nothing that would fix my problem.

I run a S13 SR20DET blacktop, TD06 top mount, cams, stock internals, boosting to around a bar. Car is tuned with a Power FC, and a Profec B boost controller.

The car ran great all summer, and then at the last event started acting up. I hadn't changed a thing since I last ran it, so I'm really unsure what could have happened to make it suddenly run lean.

The car will run good, and then somewhere around 5k will start a lean misfire.

Since the problem developed, I've checked fuel pressure, which was 40ish psi at idle and 60ish psi under load, so I dont think its the FPR/filter/pump? The spark plugs are all the same across the board, so I dont think its a bad injector?

Anybody have some suggestions? Its really important I figure it out before the weekend..

Thanks.


Edit - I know on a MAF car a boost leak makes the car run rich. My car has a MAP, so will a boost leak still make it run rich?

[S14_Kouki]

do u have a a/f gauge?? what size injectors do u have??

[lourens13]

No A/F gauge. I am not %100 on the injector size, as I bought the motor partially complete as it is today, but I was told they were 550's.

[army240]

A boost leak would not cause the car goes lean, except if the leak is on a vaccum hose going to the map. I guess you run a Power FC on your car so you could check if the value on your Power FC and your boost gauge match.

And oh yeah... you should invest in a good A/F gauge... it's a must for tuning!!!

Off Topic : Where are you from in Canada?