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SR20 HELP! Motor just isnt runnng right Im too dumb to figure it out lol

2K views 30 replies 10 participants last post by  C - ROD  
#1 ·
Well this thread might start a little long so here I go.
I bought my car about a week ago and I knew it had problems but didnt think it would be this hard to figure out. the car has a SR20DET redtop stock everything pretty much. Front mount intercooler, bov, all that small stuff.
The car feels like its at around 100hp mabye 140 max. When I slightly push the gas it accels normally and you could hear turbo start to spool at about 2.5 mabye 3 so Im pretty sure the turbo is doing its job. But the rpm's go up WAY too slow in every gear. It feels super slow, slower then a stock motor. I drove my friends sr20 and its a world of difference. Anyway when you gas it about 30% it seems to be faster then 100%. in fact 100% throttle makes it a bit slower. Its really hard to describe with words but i'll try.
At 1-2rpm its great 2-3 you feel the turbo spool a little 3-4 you hear the turbo spool faster but the power from the turbo is literally GONE. In fact it actually slows the cars accel to where you feel like your not even pushing the gas pedal at all for a split second. and from 4-7 it jerks with power then no power about 3 or 4 times.
Ill try to illustrade though percentages
RPM's 1-------2-------3-------4-------5-------6-------7
Power 90%------100%------10-20%--50%10%60%10%60%

Sorry thats the best I could do. Now here is what I tried and found out about the car.
Me and my shop concluded that it wasnt loss in turbo or a leak because he said the welds on everything was good and you would hear an air leak when I gassed it. The throttle response is good and engine and turbo respond when they should. So we thought air or fuel.
I saw that one of my injecters was slightly higher and lightly leaking and even though I have an upgraded fuel pump, I could not be shooting enough fuel. So we took it out and the fuel rail was bent and the fuel presure regulator was "halfassed" with some acehardware bolt. So I bought a brand new fuel rail/fuel injecters/regulator from a stock SR20 redtop and installed. The thing fit nicely but in the end the car was still performing incredibly poorly. Before i left the last 2 things we could think of was either my Mas. A: Z32 mas might solve it because of the lack of air it allows or B: What I personally think it is, we fould out that my ECU was the stock 240 and not the SR20 one. I def hope that will solve everything.


Could you guys help me out please. If you have any Q's feel free to ask I will tell you anything.
 
#2 ·
What ECU are you running? You should either be running a 62 or 63 for a red top IIRC. I'm suprised as hell an SR would even run with a KA ECU. About the Z32, regardless of the extra volume of air the Z32 can measure it won't solve your problem unless you have either a retune or AFC, fuel maps on a stock ECU just are not calibrated for a Z32 MAF. Lack of power and slow revs could also result in a faulty coil pack. I had a similar problem with slow revs and no power, and it turned out to be a failing coilpack. First things first though, get yourself a SR ECU. Shouldn't be more than $250 last time I checked. I don't know too much either so i'm pretty much in the same boat as you but hey hope it helps either way.
 
#3 ·
wow thx man you might be right, I havent even checked the coil pack. And my question about the ECU is what is the difference between the 62 and 63? Sorry im still new at this.
Also I have an ebay Greddy intake manifold. Could that affect anything in any way?
 
#5 ·
I dont have a boost guage but the turbo is spooling properly and the blowoff is louder as I put more presure so I think its good. As for the exhaust...I have an N1 and my friends SR20 has the same thing, but he gutted his cat and its only a bit louder. Its not too quite. Im getting the ECU this week hopefully that fixes it =/
 
#6 ·
i had something similiar like that, turned out my BOV was leaking boost. ran fine, but didn't have any power at all...and also if you're running a stock 240 ecu, that soundss like a huge problem...like the guy said above, i dont see how an SR would run on a stock 240 ecu....i think the diff. between the 62 and 63 ecus are the 62 is for manual and 63 is for auto (maybe the other way around) you should be able to run an auto ecu in a 5speed car. swap ecu's and if that doesn't work...get a damn boost gauge and see what kinda of vacuum you are getting what kinda of boost you are pushing....
 
#7 ·
well I found out that I just trusted my friend and didnt double check the ecu and it was a code 62 SR20 ecu. So now im kinda confused on what it could be. Im thinking coilpack and someone said igniter or turbo might be going out.
 
#9 ·
ignition timing. just try it. mine was like that. it was retarded like 10 degrees and you could hear the turbo spool like crazy but the car didnt go anywhere. just a thought. real timing should be 15 degrees advanced.
 
#10 ·
im having a similar problem. car runs great until boost hits.. then its slow... in vac its normal. BUT this only happens when the car warms up! its fine for the first 20 mins it's running then all of a sudden it gets all boggy and slow revving. whats the deal???
 
#11 ·
aNskY said:
im having a similar problem. car runs great until boost hits.. then its slow... in vac its normal. BUT this only happens when the car warms up! its fine for the first 20 mins it's running then all of a sudden it gets all boggy and slow revving. whats the deal???
What part of NY are you from Ansky? Drop me a PM maybe we can meet up and I can help you trouble shoot.
 
#12 ·
i just changed my plugs and 1 & 4 were soaked in oil. i had a problem with #4 injector previously. i have read injector problems may cause oil on plugs but that doesnt make much sense to me. this all started during a run with a turboxs mbc installed, the thing would NOT turn down no matter what i did. ran 18-20psi a couple times (stock t25) could i have blown rings?? :(
 
#13 ·
check your timing. you could be off quite a bit. make sure you know how to time the SR from the FSM. Its a pain in the ass but it might be your problem. And your ECU may be correct but not functioning correctly. It wouldn't hurt to try a friend's ecu just to double check.

changed the fuel filter lately? get a fuel pressure gauge and temporarily hook it up to the pressure side of your fuel rail and see if it is getting the proper amount. Also the boost gauge is important.

Is the car making any strange noises and is it hard to start?
 
#14 ·
were the tops of the plugs soaked in oil also or just the electrode part of the plugs. you may have a bad valve cover gasket leaking oil onto the plugs from the top. If you were boosting 18-20psi with the mbc closed then you had something hooked up wrong. Either you had the vacuum lines switched around or there was a leak in one of hte lines. The blue nipple goes to the wastegate, the brass one goes to your vacuum source. What vacuum source are you using for your wastgate also? make sure its a good source. I wouldn't run it if you're boosting that high on stock t25 and stock headgasket, you're just asking for problems. Plus if you're running that high of boost on stock injectors you're probably running pretty lean which we all know isn't a good thing. Get all supporting mods before you try turning up the boost. Injectors, Maf, SAFCII (atleast) wideband..ect.
 
#15 ·
the plugs are not covered in oil on top. just from threads down.

yes sometimes the car is hard to start if its been sitting say overnight, sometimes it starts right up.

how would bad timing or fuel filter foul plugs with oil?

anyway, i didnt intend to run that boost. i was trying to run 12-13psi. i think the mbc is just complete garbage (ssautochrome shit). i turned it down countless full rotations with no results. had it hooked up to nipple on coldpipe > brass side of mbc > wastegate. supporting mods? i was under the impression that the t25 would be fine at up to 15psi without injectors and a maf. i am running turboback 3", 2.5" ic pipes, big fmic core, walbro255.
 
#17 ·
Initial Drift said:
What ECU are you running? You should either be running a 62 or 63 for a red top IIRC. I'm suprised as hell an SR would even run with a KA ECU. About the Z32, regardless of the extra volume of air the Z32 can measure it won't solve your problem unless you have either a retune or AFC, fuel maps on a stock ECU just are not calibrated for a Z32 MAF. Lack of power and slow revs could also result in a faulty coil pack. I had a similar problem with slow revs and no power, and it turned out to be a failing coilpack. First things first though, get yourself a SR ECU. Shouldn't be more than $250 last time I checked. I don't know too much either so i'm pretty much in the same boat as you but hey hope it helps either way.
It's not the fuel/IGN maps that cause the Z32 mafs to not work with the factory computer, it's the difference in voltage between the two...when the MAFS reads the air coming in it sends the voltage of that reading back to the computer, when the factory MAFS' voltage is maxed out it would be beneficial to run the Z32 MAFS.
 
#18 ·
nakedave said:
I'm having kinda the same problem guys, but mine is just when the car is still cold, it only does for like the first 10 mins. Once its good and warm it runs fine, minus the occasional hick-up.
check your coolant temp sensor
 
#19 ·
Nismo241 said:
It's not the fuel/IGN maps that cause the Z32 mafs to not work with the factory computer, it's the difference in voltage between the two...when the MAFS reads the air coming in it sends the voltage of that reading back to the computer, when the factory MAFS' voltage is maxed out it would be beneficial to run the Z32 MAFS.
hmmm don't know where the hell I got fuel maps lol then again it was 2am when I posted that, thanks for the clearing that up.
 
#21 ·
nakedave said:
I'll check it out, but how would that affect how the motor was running, especially when its cold??
when your engine temp is cool, its gonna add/need more fuel...if you're not getting that extra fuel, it will cause something like that. I had something similiar to that...only it would start and run fine, but wouldn't start up after it was warm. Not 100% the problem but and easy and cheap place to start.
 
#23 ·
on the intake manifold next to the valve cover, there are 2 there, ones a sending unit and the other is the sensor, a 12mm and a 17mm iirc.
 
#24 ·
well, ever since i changed the plugs last week the boggyness went away. i just went and got a compression tester. took the plugs out... no more oil.... and 150 compression across the board!

could i have detonated enough to force a little oil past rings once? because this seriously stumps me. in any case im glad my car is ok :)
 
#26 ·
s13envy said:
i dont see how changing ur plugs fixed your compression but glad everything is ok now lol
no no i never checked the comp until yesterday. when i took the plugs out to check comp there was no more oil on them. i drove it about a hundred miles, maybe more.

also realized last night i forgot to go wot while cranking. that should have pushed the numbers to about 155 or so, correct?