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Discussion Starter #1
Hey guys. I have a 92 ser with a T25 bluebird kit running from a bluebird ecu. The problem I am having is that the turbo seems to run normally and spools at about 3k rpm but the car stumbles, backfires and runs real rich until about 5k rpm. At that point it seems to sort the air/fuel mixture out and takes off. I am determined to get this fixed but don't want to just throw money at several different things. What is going on and how do I fix it?


Thanks!
Jason
 

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agent camel toe
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pressure test the pipes..also what gap r u running on the plugs
 

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Also, check your base timming, how many psi are you using? did you changed your fuel pump?
 

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Discussion Starter #7
Also, check your base timming, how many psi are you using? did you changed your fuel pump?

Base timing should be okay. We tried to check it but when we unplug the tps the needle jumps all over the place and can't get it to stop. I am running at 10 psi right now and the fuel pump is a walbro 255.
 

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sleeper
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It does sound like a possible boost leak. Also, get the car into timing mode and make sure the timing is correct. I've read that it can be difficult on the older B13s but it's something that needs to be done. You can try searching here or the se-r.net mailing list archives.

Also, make sure your TPS is adjusted correctly and then reset the TPS idle memory. Lastly, get some new plugs, preferably heat range 7.

Oh yeah, you are using the correct sensors for the ECU right? Make sure it's reading the correct coolant temp.
 

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Discussion Starter #9
It does sound like a possible boost leak. Also, get the car into timing mode and make sure the timing is correct. I've read that it can be difficult on the older B13s but it's something that needs to be done. You can try searching here or the se-r.net mailing list archives.

Also, make sure your TPS is adjusted correctly and then reset the TPS idle memory. Lastly, get some new plugs, preferably heat range 7.

Oh yeah, you are using the correct sensors for the ECU right? Make sure it's reading the correct coolant temp.
I know how you are supposed to get into timing mode but it wouldn't cooperate. The plugs that are in there now are NGK platinums. If those won't work then what would you suggest? The only sensor I have had trouble with is the o2 sensor. I have been given a very broad list of suggestions on what should work and two of which have not made any difference. That is why before I try the last one and waste more money for another sensor I wanted to see what else could be the problem. I have wondered for a while now if it might be the o2 sensor but other people "in the know" say that isn't the problem. It's interesting that you bring up the coolant temp because the car runs a little hotter now according to my stock temp gauge. Instead of being in the middle of the gauge it a little further to right. Not apparently in danger of over heating because I have driven about 2000 miles since the install. How do I make sure it is reading the right coolant temp?
 

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ditch the platinums and get bkr7e's. you're current plug is too hot. Go with a .030 gap and i bet some of the issues sort out. I bet you're having boost leakage at the same time... what are you getting afr's from? I really hope it's a wideband!

also, the stock water temp is really bad on resolution. I've heard guys say that their aftermarket gauge will move by 70-75 degrees without the stock gauge moving.
 

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Discussion Starter #11 (Edited)
ditch the platinums and get bkr7e's. you're current plug is too hot. Go with a .030 gap and i bet some of the issues sort out. I bet you're having boost leakage at the same time... what are you getting afr's from? I really hope it's a wideband!

also, the stock water temp is really bad on resolution. I've heard guys say that their aftermarket gauge will move by 70-75 degrees without the stock gauge moving.
Is the bkr7e an ngk plug? I will have to try and re-check for a boost leak somehow. The only way I have to monitor temp right now is the stock gauge. But I have also wondered if some of that may be due to the fact that I still have the ac condensor in the car. I am planning on taking it out to allow better air flow to the stock radiator. I will most likely purchase a koyo this summer.
 

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Are you using the stock DE harness with the BB ECU? If so, the wiring for the O2 sensor is a litlle different. My car used to run better with the O2 sensor disconnected.
 

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agent camel toe
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i run bkr7's off a 2001 volvo s80 turbo gapped at .028..unplug the o2 to see if the problems stops..it also sounds like ur runnig the jdm coolant temp sensor
 

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sleeper
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ditch the platinums and get bkr7e's. you're current plug is too hot.

also, the stock water temp is really bad on resolution. I've heard guys say that their aftermarket gauge will move by 70-75 degrees without the stock gauge moving.
Platinums are fine if they are the correct heat range. I ran plats in my car for the whole 150k miles, of which the last 80k were boosted, with lots of road course time. Plus, you can generally run a bigger gap with plats compared to coppers, so you should get better gas mileage. I changed them roughly every 40k miles, and even that was a little bit of overkill. If you keep the boost down and only daily drive, you can get away with heat range 6. For more serious driving and more boost, use heat range 7.

The stock temp gauge starts to budge somewhere around 110F, is at 1/3 at 160F, and doesn't move from 170F-220F.

Do you have anything to hook up the to the car to see what it's doing? Techtom? Cable for Nissandatascan? Calumsult? Being able to read O2 voltage, coolant temp from the ECU, MAF voltage, etc, are invaluable in trouble shooting.

I know the car can be a royal pain to get into timing mode, but it can be done. Like I said, search the se-r.net mailing list archives. If anything, just check the TPS and reset the TPS idle memory, it's free to do :)

Also, did you get the 300zx tt or Nismo radiator caps? (1.2 or 1.3 bar IIRC). They'll improve the cooling system, less chance of overheating.
 

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agent camel toe
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Platinums are fine if they are the correct heat range. I ran plats in my car for the whole 150k miles, of which the last 80k were boosted, with lots of road course time. Plus, you can generally run a bigger gap with plats compared to coppers, so you should get better gas mileage. I changed them roughly every 40k miles, and even that was a little bit of overkill. If you keep the boost down and only daily drive, you can get away with heat range 6. For more serious driving and more boost, use heat range 7.

The stock temp gauge starts to budge somewhere around 110F, is at 1/3 at 160F, and doesn't move from 170F-220F.

Do you have anything to hook up the to the car to see what it's doing? Techtom? Cable for Nissandatascan? Calumsult? Being able to read O2 voltage, coolant temp from the ECU, MAF voltage, etc, are invaluable in trouble shooting.

I know the car can be a royal pain to get into timing mode, but it can be done. Like I said, search the se-r.net mailing list archives. If anything, just check the TPS and reset the TPS idle memory, it's free to do :)

Also, did you get the 300zx tt or Nismo radiator caps? (1.2 or 1.3 bar IIRC). They'll improve the cooling system, less chance of overheating.

that right their is pure knowledge:)
 

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Well, yeah, I realize plats can be ok, but platinum is a weak conductor and honestly I'd much rather have the coppers. In any case, if he's using a stock plug, he's got 5 heat range plugs, right? That's what I was going off.

I've never heard of being able to use a bigger gap, it seems contradictory to me due to the conduction properties. Educate me on that one, please. Bigger gap would always be better...
 

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sleeper
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I've never heard of being able to use a bigger gap, it seems contradictory to me due to the conduction properties. Educate me on that one, please. Bigger gap would always be better...
Opps... I mispoke. Plats SHOULD be gapped bigger to attain the same spark power.

http://www.se-r.net/engine/platinum_copper_ngk.html

But, if you consider that they don't wear out nearly as quickly, you can keep the gap bigger :tongue: yeah, lame attempt to save my ass.

t bags, ya know, 9 years is a long time to get to know a car :) I learned stuff after the first wave of guys to do anything. I learned about turboing our cars from that first wave of guys like Mike Gossilin, Ben Davis, Jeff Nayert, Mike G., Jody M., Julian Hancock, George Roffe, and a handful of other guys. Back in the day, everything being developed was still new, so everyone communicated together to figure out what worked. Even with the help of the 1st timer guys, I still ran into a few issues, but those guys had figured out about 85% of it already.

But my strategy was, being a poor college student, let someone do most of the development work first to see how it worked out, and then copy if it was good. I followed a lot of what Mike Kojima did with his 200sx. Stuff like motor mounts, control arm bushings, suspension setup, brakes, tranny fluids.... just about everything on the car.
 

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Discussion Starter #18
Are you using the stock DE harness with the BB ECU? If so, the wiring for the O2 sensor is a litlle different. My car used to run better with the O2 sensor disconnected.

Yep, I am using the stock de harness with the BB ecu. I was hoping that just getting the correct o2 sensor would solve the problem but I am not sure. To me it seems to make a little bit of sense because if the ecu cannot get any feed back from the o2 sensor then it wouldn't know what to do with the a/f mixtures and keeps things rich to be safe. But that is my thinking with my very limited knowledge.
 

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agent camel toe
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Yep, I am using the stock de harness with the BB ecu. I was hoping that just getting the correct o2 sensor would solve the problem but I am not sure. To me it seems to make a little bit of sense because if the ecu cannot get any feed back from the o2 sensor then it wouldn't know what to do with the a/f mixtures and keeps things rich to be safe. But that is my thinking with my very limited knowledge.
i had an issue with my 200 and after accidentally disc the o2 she ran like a rocket..so $63.56 later i have a new 300zx o2

with ur u12 ecu u should have all of the jdm sensors installed..especially the o2 it should either be the jdm o2 or the z31

t bags, ya know, 9 years is a long time to get to know a car I learned stuff after the first wave of guys to do anything. I learned about turboing our cars from that first wave of guys like Mike Gossilin, Ben Davis, Jeff Nayert, Mike G., Jody M., Julian Hancock, George Roffe, and a handful of other guys. Back in the day, everything being developed was still new, so everyone communicated together to figure out what worked. Even with the help of the 1st timer guys, I still ran into a few issues, but those guys had figured out about 85% of it already.
its members like u that make me read up more info on cars everyday:tongue: ..sometimes on sat/sun mornings while fighting a hang over and sipping on some green tea figuring out how to make my car more reliable or whats the next to do mod list..i have only been in the sr game 5 years but after the second year u realize what works and with det's u need all the info u can get...either way cheers
 

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Discussion Starter #20
i had an issue with my 200 and after accidentally disc the o2 she ran like a rocket..so $63.56 later i have a new 300zx o2

with ur u12 ecu u should have all of the jdm sensors installed..especially the o2 it should either be the jdm o2 or the z31


What are all of the sensors that I need? I was told I only needed two for my setup. The temp sensor and the o2.
 
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