rb25 air/fuel problem

[ForceFed240]

So i picked up a s14 that had already had the rb25det swapped in but it runs like poop so i was hoping you guys could possibly give me some insight on what could be the problem.

It idles right around 14.7 when I hit the gas the air/fuel guage gets over 17/1 and then drops down to around 10/1 a few secounds after and runs super shitty. Ive checked all the vacuum lines and change almost every hose just to make sure, cleaned the maf and changed plugs and checked the coil packs.

Any one have any suggestions on what this could be? how to fix it?

mods are
aem uego wideband
aem tru boost controller
freddy intake manifold with a big throttle body
large fmic
walboro pump

[funktown240]

Stock ECU? Check the tps voltage with the throttle closed. My stock ECU did not like my Q45 TB, ran like garbage.

[ForceFed240]

Yeah i was thinking either that or a sticky fuel pressure regulator cause my fuel pressure gauge is reading a bit high too.

[di-devol]

Try and find a stock TB to throw on there, the ecu isn't tuned for the bigger one on there.

[ForceFed240]

I cant throw the stock one on cause its got a custom flange welded on. any recommendations on an ecu?

[240sxrb25]

how close is the maf to the turbo

[ForceFed240]

its at the stock distance im still using the stock turbo air intake

[Luvs2slide]

check to make sure your timing is set properly. stock rb25 ecus run real rich.

[ForceFed240]

i was fiddling around with it and noticed at 2000rpms its drops down to 1500 and if i hold it at 2000 its bounces between 1500 and 2000 repeatedly any ideas? coolant temp sensor?

[ForceFed240]

heres a video showing that problem^
Rb25 revving problem - YouTube

[fliprayzin240sx]

I'd set the TPS. But since you brought it up, whats your base fuel pressure set at?

[ForceFed240]

Its set to 43

[fliprayzin240sx]

I'd say TPS...but since you said you just picked up the car and it runs like poopie, I'd go over the whole engine just to get the warm fuzzy. I'd double check the mechanical timing on it and make sure the timing belt marks all line up at TDC. Re-stab the CAS, reshoot it and make sure the base timing is at the 4th mark from the left (0, 5, 10, 15). Double check the spark plugs, should be atleast a heat range 6 and gapped to .030. Wouldnt hurt to spray the MAF sensor filament with a MAF sensor cleaner.

[ForceFed240]

Yeah I've been trying to go through every thing i havent check the timing yet I was kinda saving that till last cause it sounds like a pain in the balls to check lol

[fliprayzin240sx]

You can atleast put it on TDC, take the cam gear cover off real quick and atleast verify that the belt timing marks line up on the gear marks. If they're off, turn the crank over a couple of times and see if it would line up. If they're off still after a couple spins, then you'd have to pop the main pulley off and get the front cover off.