sr20 s14blacktop problems!

[C - ROD]

OK, first of all im usually pretty good with SR's, but never messed with the notchback motors, first of all we started having problems friday night, it was breaking up at like 4200 rpms, then we stopped & cleaned the MAF, reset the ECU & took off, well then it wouldnt go past like 4000 rpms, & at 4000 rpms it sounds like its hitting the factory rev limiter it never builds more than 4 lbs of boost, it has decent power until it hits around 4000 rpms, then it will not accelerate past that point, when u shift to the next gear, it accelerates until it reaches around 4000 rpms then it hits what sounds like the rev limiter, & it doesnt build more than 4 lbs of boost

ANY help would be gratly appreciated

[C - ROD]

anyone?

[C - ROD]

ok we found that the intake pipe was smashed in at the turbo, like the turbo had sucked it in or something which caused it to collapse, so we put the one on from my redtop & cleaned the MAF again, now it will rev past 4000 rpm but it doesnt build any boost, it takes a long time to accel between 2000 rpm & the time u shift gears, it seems like either the MAF isnt reading that the air is coming in or the TPS is telling the ECU that the throttle isnt open 100% more like 10%

[C - ROD]

i forgot to mention that it runs smoothly at idle with no problems & we have set the base timing at 15 deg. then set final timing to like 17 deg.we cant figure this **** out!
Modified by C - ROD at 1:39 PM 5/27/2007

[jr_ss]

Maybe your wastegate actuator took a dump on you if you aren't building any boost. If the diaphram is torn or cracked it won't hold the wastegate flapper closed.

I'd check for any codes. Codes will tell you if something is up or not.

[C - ROD]

we checked to see if the W/G was stuck open, it wasnt, also it didnt open when we reved it under no load, as for the codes i tried to get them like i did on my redtop ECU, but there wasnt a led light on the inside of the ECU, so how do i retrieve codes on this system, do i need to hook up something for the Check engine light? we had the harness done at wiring specialties so maybe its already hooked up? but there isnt a light on the dash for it

[S13FASTBACKSR]

With s14/15 sr ecu's you do not retrieve codes the same as s13 sr's. With s14/15 sr ecu's you have to pull codes through a consolt or ODB checker.

Ok so just to make sure..the only problem you have now is your not making boost? you have perfect idle and you can now rev to redline but you just arent making boost? and you are absolutely sure your actuator is fine? how do you know..did you hook up an air compressor to it to test it?

[C - ROD]

well that is not the only problem, it doesnt really rev very fast past 2500 RPMs, it takes a long time, that could just be cuz the turbo isnt boosting, but u can hear the turbo spooling & it spins fine by hand with minimal shaft playwe did not check it by applying compressed air we just pulled on the rod to make sure that it wasnt stuck open, & then made sure it didnt open up whenever we revved it up

[S13FASTBACKSR]

well does it misfire or hesitate (rev unsmoothly) after 2500 rpm..or nice and smooth but slow?

[C - ROD]

well usually its smoothly but sometimes it breaks up at around 4000RPM, but other times its real smooth but slow to rev

[S13FASTBACKSR]

vac leak, boost leak, timing, spark plug gap...are you running rich at all?

[C - ROD]

we have redone the timing 3 times, its dead on, couldnt find any boost/vacuum leaks, ill check the spark plugs. i didnt really pay attention to the A/F ratio when it stared acting up

[S13FASTBACKSR]

well if its not pouring out black smoke its not the o2 sensor..maybe if its slightly rich or lean it could be the tps...also put on a brand new 300zx TT fuel filter the one you have now may be clogged

[CoupedUp]

Or a bad pump.

[C - ROD]

we checked the TPS this afternoon, it had a smooth voltage increase until about 3.21 volts then it went to OL (open) then to 3.58 volts then continues to increase smoothly till around 4.68 where it tops out, so im pretty sure that we have a bad TPS. i was reading in the SR20 parts guide & they said u could use a 95 KA with a little soidering? does that mean that u have to swap the connector, or does that mean u have to do something to the sensor itself? im confused on this one. a new one is only $105 from phase2motortrend so we might be buying that if its a pain in the *** to use the KA

[C - ROD]

well if its not pouring out black smoke its not the o2 sensor..maybe if its slightly rich or lean it could be the tps...also put on a brand new 300zx TT fuel filter the one you have now may be clogged

we put a new filter on it when we got her runnin, about 600 miles ago, but it could still be clogged i guess if the tank had crud on the bottom, well try that b/c a new filter wont cost us a dime

Or a bad pump.

good possibility, we didnt install a walbro, just the S14 pump that came with the swap, we need to put a walbro in it regardless so ....

[S13FASTBACKSR]

i thought you installed a new walbro thats why i didnt list the pump as a possibility...if you want to test it there is a way..do you have a fsm? also a 91 sentra se-r tps is direct plug and play..just make sure you look at a picture on the stores computer before you order..they kept giving me the wrong one where the lever was flipped upside down

[C - ROD]

i thought you installed a new walbro thats why i didnt list the pump as a possibility...if you want to test it there is a way..do you have a fsm? also a 91 sentra se-r tps is direct plug and play..just make sure you look at a picture on the stores computer before you order..they kept giving me the wrong one where the lever was flipped upside down

that TPS is a direct for the s14 SR?

[C - ROD]

we plan on installing the Walbro, but just havnt got around to it yet

[S13FASTBACKSR]

sorry forgot this is for a s14 sr..i dont know about that..your gonna have to ask around a little more or just by an oem replacement one which is probably what I would do

[C - ROD]

yeah i wish it was the 13SR, it would be a little easier to diagnosewe also checked the W/G last night, it is good, it took 7 lbs to open it, no less

[S13FASTBACKSR]

thats good let us know if the tps solves the problem

[C - ROD]

i willcan we use a Q45 if we install the throttle body on it too?

[S13FASTBACKSR]

q45 TB yes...q45 TPS I dont know and I dont think so

[C - ROD]

we are trying to get a S14SR20DE throttle body & TPS, its direct bolt on & the sensor is the same, & the throttle body is 10mm larger than the DET SR

[C - ROD]

well we threw on a KA throttle Body & TPS from a 95, cleaned the MAF & put the right intake tube on it........................ITS FIXED, now boosting almost 10 PSI =], running like a striped *** ape!!

[S13FASTBACKSR]

congrats bro!!