sr wont rev past 3k

[mxsx25]

the car is a sileighty with an sr swap, mainly stock, it has an apexi boost controller and thats pretty much it, but the problem is that when under a load the car will not rev past 3k but it will do fine if not under a load, im thinking it may be a wastegate issue becuase it isnt really going into boost range, i guess it could be the tps or maf but just curious if anyone else has ran into this problem...any help would be appreciated

[SHIFT_*grind*]

Either you have a problem with your MAF, or you have a massive boost/vacuum leak somewhere (i.e. intercooler hose popped off).

If you want more detailed info, search for one of the other 8000 threads on this topic, they CAN'T be that hard to find.

[180sxLove]

MAF sensor is the reason why you cant rev past 3k.. unplug and see if the problems continue, they should.

Replace the MAF and it should be OK

[Slow Poke]

You can also trying cleaning the MAF, that works sometimes as well. GL

[TOMKAIRA93]

boost leak!!!!! But yeah, search first man cuz I had the same problem and had a similar thread, so there is info out there regarding this subject/ topic.

[mxsx25]

okay so i swapped out the maf sensor on the sr and tightened up all the hose clamps and checkd all vacuum/boost lines and the car runs great all except for it has what ive heard is a "hunting idle" i read to test the tps and the iac, i know how to test the tps but what should i be looking for when testing the IAC? and i thought i read somewhere that the sr throttle bodies have an idle screw which im guessing goes hand in hadn w. the IAC...anyways, thanks for the help and any input is deffinately appreciated

[240sx_sr20det]

MAF has my vote. I have had the same problem before.

[StaticX27]

So what if you changed out the MAF and it still has the problem? (my current situation )

[Tops*]

How cold is it over in NH? I don't know what a "hunting idle" is, but if you're talking about a stumbling idle, clean your IACV with some CAS throttle body cleaner. It's different from the CAS MAF sensor cleaner so don't get the two mixed up. There's a complete write up in the Zilvia archive, so search for it. The topic's been covered hundreds of times. The stumbling idle could also be caused by the low temps. While I let my car sit and warm up, the idle dips under 800 and shoots up to around 1500 sometimes until it completely warms up.

[240sx_sr20det]

Well on my S13, I changed the MAF and it was fine. I then bought an S14 and had the same problems, so I changed the MAF and still had the problem. It ended up being a bad injector that was causing it to run like shit.

I don't know if thats the same problem for you, but it worked for me.

Good-luck guys!


EDIT: ^^ It's frigid as hell in NH lately.

[jayesone]

I had that same problem at the track, I blew a hole on my elbow, you cant hear it leak. but it wouldnt boost, but revs up fine. i suggest pull all the hot pipes and check them. I found that problem but now has another problem, my car wont boost past 13psi with out struggling.

[mxsx25]

well i found the problem causing my bad idle, and i am kicking myself for even asking for advice, haha, my coolant was leaking from where the hardline off the turbo meets a rubber line causing air to be in the system..i repaired the line, bled the system and it idles great now