weird problem, boost leak or something else?

[clovers525e]

i just swapped in my s14 sr and now i'm getting a weird problem out of it. it will start and idle just fine but when i go to rev it up it'll hit about 2500rpm and wont go past. it sounds like it would if it had a rev limiter where it hits every other lick. also when i hold the motor at 1000 it'll rev there and then choke and the rpms will drop about 500-700. on the exhaust end its nothing but raw gas smell and medium smoke. when you rev it up and let off the turbo makes a "chopping" noise through what sounds like the intake, my greddy bov doesnt open (no load, no boost is what i understand it as right?) and the boost gauge i have doesnt ever read anything, but i think that is because its broke. when i got the motor it has oil in the compression chambers for what ever reason so i got most of it out, ran it for a little while and changed the spark plugs today, i switched out the intercooler for a test pipe and still no improvement. i'm using a walbro 255 and a TT z32 fuil filter, 4 ply silicone hose couplers and t-bolt hose clamps. and the waist gate acthuator arm is on there fine, checked that too. i was thinking maby the maf, tps or o2 sensor, figgure i'll start with thoes

[rustest86]

if it wont rev past 2500 check the maf, maf conection, and or wires to make sure they were connected right when the swap was done.

not trying to be an a$$ but this has been discussed before and its prob in the FAQ or a sticky somewhere. should try seaching before posting

also are you running the stock maf of a bigger one? if your running a bigger one you need a safc or something along that line for maf output corrections

[clovers525e]

ya, i'll have to go through and recheck the wireing, i'm running a s14 ka maf with the four wires to it, do i need to switch it out for the s13 one? sorry about not searching, i just threw that up there really quickly at work and didnt want the boss to catch me.

[jdm180]

you can also try the CAS if you messed with that at all. might need to be adjusted or might need to be moved a tooth. if you removed the head for anyreason you might have put that back in incorrectly.

[rustest86]

yea you need a s13 SR maf, s13 sohc maf, or a stanza sohc maf for a usable stock unit. if you want to use that s14 ka unit, which is not an better than the sohc one, you need a safc of some other type of fuel computer to change the maf output signal. but yea thats what your problem is.

make sure you get an SOHC maf otherwise youll have the same problem.

[clovers525e]

i just changed the maf to a sohc s13 one and that fixed the issue i was having about it not reving over 2500 but it still idles and runs rough, when i hold the rpms it still sputters and misses.

the other issues i'm having is that when i first start it up it will idle without knocking but when i break idle rpms it will knock really breafly once and then wont do it again. the other thing is that my turbo is making alot of noise, i understood it as compressor surge but my brother said that wasnt what it was, when i rev it up and let off it makes a chopping noise from the intake and i dont think my bov is opening that i can tell. i cant read if there is any boost pressure or not since my boost gauge isnt working right now.i tryed to adjust the idle up but it is now idling really low, checked for vacume leaks and didnt come up with any, and i messed with the cas, i understood it as you just turn it until the idle smoothes out but it really didnt ever get any better or worse unless it was all the way advanced or retarded in which case it just got worse.... maby my turbo is bad? i think i need to check my compression again too...

[clovers525e]

and its still running rich as hell

[clovers525e]

bump, nobody?

[clovers525e]

do i need to switch to the ka coolant temp sensor?

[My2fast240sx]

probably not.

[CoupedUp]

Now, mind you this is on a KA, my friend had a problem that came back to the water temp sensor.

It basically ran like crap and had no power.

A bad turbo shouldn't be giving you these problems. I would swap the Temp. Sensors just to see if you can fix the problem possibly. make sure you replace the correct one. Not the one that goes to the gauge but the one that sends the signal to the ecu. Sometimes referred to as the Cylinder Head Temp. Sensor.

If you can get ahold of a timing light, I would reccomend using that to see where youre at timing wise. Dont let this frustrate you. Youll conquer it.

Check your compression, never hurts.

Good luck. I love my S14 SR.

[clovers525e]

alright, i spent a whole day f-in with it. i did a compression check a second ago and it read 150 across all cylinders and held compression fine. the compression checker i used was a little off, reading about 20 psi with no pressure, so i'm guessing 130-140 across all cylinders. with my compression checker, which also seems to be screwed up, it bumped up to 90 psi but the checker isnt holding compression. when i had the ka s14 maf installed i remember that it idled fine, it just didnt rev well at all, so atleast i know it can be done. i changed out my o2 sensor for one i baught as a replacement for the old ka motor but it didnt change anything, i took off all my intercooler piping and ran the shortest way i could but it still didnt improve. undid the tps and fiddled with it but it never improved, same with the cas but nothing. replaced the water temp sensor, nothing. \so, in the end i'm still where i started. my multimeter crapped out on me today too, so i couldnt acthually check the tps signal and the maf signal so i guess when i get payed again i can try to fix it or go buy another, along with a new compression gauge and then i'll have a better idea. i switched out the maf sensor i got from a junk yard for one a guy had down the street, no change.... so i'll have to wait unless someone else has any more ideas.... o2 sensor maby? spark plugs? maby both maf's are bad?

i'm going to post a vid on utube and put up a link so maby someone will be able to better help me, along with looking at the vacume its pulling, btw, what bar of vacume should i be reading? boost gauge started working today

coupedup, how do you check the timing on these? i'm used to plug wires thanks for the help btw

[clovers525e]

i switched back to the old spark plugs it came with and it started right up, the idle was up and down though, but that would probably be due to the unclamped hose i have running to the iacv, i guess we'll see if i run into any other problems, in the mean time does anyone have info in plugs, i used the ngks in the first page of the part cross reference page and thoes are the ones i got these problems out of...

[rustest86]

if you have the hose that runs to the iacv undone thatwould cause idle problems, and all ypur other problems. connect it to the intake system AFTER the compressor.