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View Full Version : trouble shooting tips, running bad after turbo/maf/ecu/injector install, sr20


Volchok
02-14-2009, 11:26 AM
Hey everyone, need some more advice from the experienced zilvian community. Need some suggestions, trouble shooting tips.

I just installed a new T28 w/ circuit sports steel lines, 550's, Z32 MAF, Greddy oil pan, oil cooler and intake, Megan Pulleys, Nismo motor mounts, AEM wideband, and sbc i-color boost controller. I pulled the motor to do all of the upgrades, and everyhting went pretty smooth. After the motor was back in, and everything was hooked up, i took it for a drive, everything seemed great. I hadn't yet put the clutch fan on, so I made the drive short, to warm up the engine, get oil flowing through the oil cooler and then check for leaks. Everything looked great no leaks, and it ran strong.

The next day I installed the clutch fan and shroud, and then a Circuit Sports downpipe so I could hook up the AEM wideband sensor. Then I put on a HKS Hi Power exhaust and Megan test pipe. I had cut out the muffler on the exhaust so it is just a 3in pipe all the way back.

I went to start it to see how the exhaust sounded and check the readings on the wideband. Sometimes the car can take a few to start it up, but this time it took a really really long time. When it finally did start, it was running really rough. It does to idle OK but starts to sputter and cough and gasp for air it seems when you give it gas, and there was a lot of white smoke coming out of the exhaust. When you floor it it bogs down, putter and even backfires. It was late and out of frustration, I gave up for the night.

The next day it did the same thing. These are the trouble shooting things I've done so far:

1.) I removed the spark plugs and cleaned them with a wire brush, there was some black deposits on them, and they are less than 5,000 miles old.

2.) I checked the ground on the Z32 MAF which was good, also the power was ok to the plug.

3.) Checked the power and ground to each of the fuel injectors which was also good.

4.) dumped all of the oil, and refilled to exactly 5 quarts after filing up the oil cooler core.

5.) checked for boost leaks which i didn't find, and the boost gauge is registering boost on throttle, however it jumps around as the RPM's jump a bit since it is running rough.

Thats it so far. Today i have a friend bringing over a different MAF and ECU. , the MAF I bought was used from here on zilvia, and the ECU was just tuned by Enthalpy. The only things I could think of were a bad MAF or ECU tune.

The strangest thing is that it ran great the first day. I have no idea what has happened since then. I am going to even pull off the exhaust from the downpipe to see if that does anything, as it is the only thing that changed. I don;t see how it could but I am running out of ideas and am desperately trying to make a drift event next weekend.

Any help would be appreciated more than you could imagine. This is the first time in a year my car hasn't been running and I am obsessively distraught over it!!! I barely slept last night.

Thanks!!!

rc1honda
02-14-2009, 12:44 PM
Sounds like your running super rich, which is common with bigger injectors and z32 on stock boost when you don't have engine management. What are you using to tune the car? Your build seems seems pretty quality, i would just have a dyno day to make sure you AFR's are good at start up, idle, and under load. Also just do a quick check of the timing, and change the plugs., and check for vac/gasket leaks, and MAF wiring. Sorry just read the enthaly ecu tune. Well then i would also replace your coolant temp sensor soemtimes these can make you run real rich cuz it tells the ecu that the motor is cold and it dumps the fuel to warm it up and its common to have to replace it with the swap. I assuming it's a SR. Also do the simple stuff like check the IC piping, timing,and pull any codes from the ECU. What i don't get is the white smoke with the black plugs? It's usually black smoke when running rich. IDK about that

godzilla_753
02-14-2009, 01:44 PM
i would def chack the maf wiring out, i did similiar mods all at the same time and it turned out my maf wiring wasnt right. im not sure but i think the shielding on the wires should also be reconnected (i held them together and wrapped electrical tape around it). it def helped me, car has run fine ever since

jmac636
02-17-2009, 09:05 AM
Well if the maf and ecu swap didn't fix your car it could be your injector o-rings if you didn't replace them with new ones when installing the 550's. You can buy ka24de injector o-rings for $5 at your local auto parts as a direct replacement for the sr. Make sure to use a silicone based grease for installing the injectors in the fuel rail. Other than maf and wiring problems I can't think of anything else.

Volchok
02-17-2009, 09:40 AM
this actually occurred after the install of the ecu, maf, injectors, intake, turbo, oil pan and oil cooler. Crazy thing is it ran great the first day after the swap. Thanks everyone for your help. The problem is fixed. It did turn out to be the MAF wiring. Whoever extended the original wire harnes extended the maf wirig with dat bus cable, really thina dn hardly any insulation. I traced the wiring a little and saw that a secion of it, which was all wrapped in electric tape, looked a little melted. I took it apart and saw that one of the wires, the 12+v one was all melted and adhered itself to the ground wire. I just cut the whole thing out and extended it with regual 16 gague insulated wiring. As soon as i started the car, it fired up instantly and I knew it was fixed.

Thanks again for the great suggestions, it allowed me to focus on just the MAF which turned out to be the culprit.

My other obsatacle this weekend to get the car on the track was the rear subframe stud. I was putting on collars and broke the last bolt of four trying to remove it. The nut and bolt was so stuck, it basically became forged into one piece. PB blast and an impact driver had no effect. the breaker bar finally "broke" it.

Here is the reapir:
First I cut off the bottom of the stud, just above where it starts to taper. I forgot to take a picture of the broken part, but it wasn't pretty.
http://www.teahnshawn.com/gallery/albums/userpics/10002/normal_PICT3458.JPG
Next I drilled into the stud using some white boy ingenuity, my inverted drill press:
http://www.teahnshawn.com/gallery/albums/upload/240SX/New3/normal_PICT3460.JPG
A jack and a drill, made it soooo much easier just jacked it up as I held the trigger.
Then I tapped the hole. The tap handle broke on the second rotation, cheap shit, and I had to use vise grips to finish screwing it in and out.
http://www.teahnshawn.com/gallery/albums/upload/240SX/New3/normal_PICT3461.JPG
I cut off the top of a 10 x 1.5 x 100 mm bolt with a dremel and then smoothed out the grooves so a nut would go on and used the two nut technique to get the bolt in.
http://www.teahnshawn.com/gallery/albums/upload/240SX/New3/normal_PICT3464.JPG
http://www.teahnshawn.com/gallery/albums/upload/240SX/New3/normal_PICT3463.JPG
then I tack welded the top of the bolt to the frame to make sure it didn't slip at all when tightening down the nuts and to add a little more rigidity.
here is the end result:
http://www.teahnshawn.com/gallery/albums/upload/240SX/New3/normal_PICT3466.JPG
good as new!!! tightened down to about 85 ft lbs.

handinpants
02-18-2009, 02:16 AM
white smoke, means coolant in the compustion chamber. black smoke means running rich, blueish smoke means oil in the combustion chamber...
what color was your oil when you "4.) dumped all of the oil, and refilled to exactly 5 quarts after filing up the oil coolerhttp://images.intellitxt.com/ast/adTypes/mag-glass_10x10.gif (http://zilvia.net/f/#) core." ?

have you done a compression test?
what worries me is you ran the motor with no clutch fan, hense not pulling any air through the radiator to cool the motor.

Volchok
02-18-2009, 09:40 AM
white smoke, means coolant in the compustion chamber. black smoke means running rich, blueish smoke means oil in the combustion chamber...
what color was your oil when you "4.) dumped all of the oil, and refilled to exactly 5 quarts after filing up the oil coolerhttp://images.intellitxt.com/ast/adTypes/mag-glass_10x10.gif (http://zilvia.net/f/#) core." ?

have you done a compression test?
what worries me is you ran the motor with no clutch fan, hense not pulling any air through the radiator to cool the motor.

well as I previously posted in an update, the problem was fixed. Turned out to be a bad MAF wire. The smoke was bluish, hence the oil dump/fill. I ran the car without the clutch fan on a really cold day down the street and back, less than a mile, with air blowing over the radiator. However, the water temp never went past 175 c and oil temp never over 105 c so I am sure it was fine. It ran about 10 mins.

thanks for the advice though. Its good to have helpful people around.