questions on technicals

[troll's 240sx]

I have done some bolt on mods to my car. It seems like i have done everything the right way but still having problems. Its a turbo kit that i pieced out. Is this the place I should be asking or should I go to the KA-T?

[NISTECH]

Whats your question? If myself or chris dont have the answer i can move it to the KA-t forum for you.

[troll's 240sx]

Ok. Long story shorter, put in a turbo kit that i have pieced out. I rewired my MAF for a Z32, Plugged up my egr because my exhaust manifold does not have a hole for it, ran a Jim Wolf Tech ECU, JWT fuel rail and 50lb msd injectors. With no leaks in my intercooler pipes or my MAF and my Fuel Pressure set at 34psi, the car would run rich and stall it I was to drive it. Now the car would fire one cylinder, cylinder no. 3 only. Checked for spark, and there is spark for all four. Pulled out the plugs and although they look fouled, very black all around, they still throw out spark. I switched the fuel setup back to the stock injectors, stock MAF, with the turbo still hooked up and still it does the same thing. I have tried it with the stock ECU too with the same results. Are there any vacuum lines that I seem to have missed? Oh and replaced the CKP sensor recently because I broked it. I would post up pictures but I dont know how to.

[NISTECH]

I assume your car is a 95 or newer since you mentioned the ckp, all that sensor is for is diagnostic purposes and has nothing to do with engine control.

I have to say here check your grounds as priority 1 especially the air flow meters ground. if that is reading wrong it will dump a ton of fuel in. next check your 2 wire coolant temp sensor at the front of the intake manifold. see if its terminals are corroded.

also check your intercooler piping make absolutly sure you have no leaks in it.

[troll's 240sx]

Yea its a 95 and the grounds are the first that I checked. The battery to chasis ground, one bolt on to the head on the exhaust side, one beside it to the hose brackets, and one by the thermostat housing, and the 2 wire there are fine also. I wander if it is my MAF, I mean I think I wired the z32 MAF right. One of the ground to the wires and the brown to chasis. If I have it wired wrong then when I put the stock one back on it does the same thing. I have my wiring wired simutaneously, meaning both can be plugged in if I wanted to. My injectors the same way, will this be acceptable though? I dont have any DTC's.

[NISTECH]

no dont plug them both in at the same time you wil confuse the hell out of the computer,not to mention possibly damaging it. what you need to check is your groud for the maf with a volt meter. it cant be more the .02v drop between the sensor and the intake manifold. On the coolant temp sensor I was telling you to unplug it and make sure there is no corrosion in its connector.

[troll's 240sx]

Yea I know not to plug them both in at the same time, but checking the voltage drop, you mean in the ground wire that goes to the MAF, is that the one grounded on top of the thermostat housing?

Checked it and it was only .014 volts. Would it be that my plugs are too fouled to start but enough to throw a spark?
Modified by troll's 240sx at 5:58 PM 4/5/2005

[NISTECH]

yea but your back probe the ground wire at the maf with the key on,prefferably running and put your other lead on the manifold[not on the ground screw]

yes clean your plugs if they are fouled.

[troll's 240sx]

Ok yea checked it at the manifold not screw, with power on, not engine on because it wont stay running. I tried to give it a better ground now and it reads 0.000 volts. Cleaned all the plugs then it started and ran perfect for 10 seconds then it stalled. If I give it a little gas then it flutuates from running good to almost stalling. Seems like we are progressing though. I just bought the plugs not too long ago but do you think I should try newer ones?

[NISTECH]

what kinda plugs you got? NGK?also did you chack for corrosion in the coolant temp sensor connector?

[troll's 240sx]

I am running bosch plat. and I know its not the right one but for now because my ngks are still on their way. Yes I check the coolant plug and it has no corrosion on it.

[NISTECH]

ok when it stalls do you pull the plugs imediatly and inspect for saturation? You could possibly have a leaking injector. Honestly though I have seen those bosch plugs make nissans run like absolute crap. I think you should wait til you get your NGK's to diagnose further since you might be chasing a ghost.

[troll's 240sx]

Yes I checked them imediately after it stalled and I guess they were saturated because they had wet fuel on them. Yea I should wait for the NGK's, dont know why I bought the bosch in the first place, just wasnt thinking. It blew my second Honda engine by releasing (as I call it) the electrode into my combustion chamber and gernading the engine. I had a 13/1 compression and there wasnt much I can do. Thank you for your help. You got me a long ways and I appreciate it. I'll post up another one if something else goes wrong.

[Magnes]

Just a question on the side here...

How do you plug up the EGR, and how do you find an aftermarket ECU that will take this into consideration? Or was the ECU designated 'not for street use'?Also, how do you avoid burning up the cat (or have you removed it)?

[troll's 240sx]

You remove the two egr valves with the pipe that goes to exhaust and fabricate a plate to screw on and plug it, located at the firewall behind the intake manifold. It has two screws that hold it in not three. Jim Wolf Technologies programs your existing ECU and I dont know if they put the EGR in consideration but I kept the EGR solenoid plugged in still, that is the electrical part. And yea it is designated for "not for street use". For the Cat I replace it with a test pipe or a straight pipe.