Just finished s14 sr install, running very rich

[VisionRx7]

Ok... I just put a s14 sr20det blacktop into my 89 240sx. It fires right up and will run. I got the timing set right in ( second mark from the right on the crank ). If I take the car for a drive it will kind of buck on me a little bit when not at WOT. When it's at WOT it pulls really hard. After I take the car for a ride (abou t a mile or two), it fouls the spark plugs out from running so rich. If I rev it, flames will shoot out. I went over all my wiring, and everything seems to be right in place, and all the grounds are hooked up. At first the MAF extension was held together with crip connectors, because I was all out of solder when I extended it... I soldered it today, but haven't tried new plugs yet, because I don't want to waste $30 again if that isn't the problem. I thought maybe the crimp connectors were causing to much resistance and causing the computer to think the engine was getting more air than it is. Do you have any other ideas as to why is it running so rich?
Thanks,
Jesse

[Sil-Abc]

check the TPS sensor. Get a voltmeter to it and check that out. check for vacuum leaks too

[VisionRx7]

Ok, I tested the TPS out today and it's working fine. I put new plugs in and fired it up... the car sounded like a wrx again. Turns out that the coil in cylinder #2 is barely firing (not even enough to spark the plug). I switched the coil with one from my old redtop and it did the same thing. I then gave it a straight ground, and it got a little stronger, so I gave it a straight power source and again it got a little better, but still not enough to spark the plug! I changed out the ignition harness with the one from my redtop and it didn't help anything either. I also gave the ignitior chip another ground without any luck. The ecu takes care of the pulsing, so why would it be so weak only on that one coil? Any more ideas?
Thanks,
Jesse

[2-4-0]

I'd just say check of vaccum leaks. Also has the issue of a faulty MAF been addressed?

[VisionRx7]

yea, the MAF is good. I checked for vac leaks also. Thanks for the suggestions!

[nrg]

check compression, injectors, fpr, and wiring.

[bigOdom1]

when mine first started up we had to let it idle for a little while since it had been sitting for so long it cleared up all those problems

[VisionRx7]

hmm... It ran alright at first, then the problem started. I was able to take it for a ride and it had a ton of power. I shut it off, wired up some gauges (A/F, autometer water temp, stock tach, stock water temp), then this started. I was able to take it for a ride after the gauges, but had to retime the car, which makes me think it might be the CAS. It is just that one coil running really weak. I switched over everything from my old engine that ran fine. I am using the ignitor and CAS from my old engine, then I switched over a coil and the ignition harness from the other engine to see if it was just that one coil but no luck.

[nrg]

when you swap over the CAS, did you set the engine to TDC?

[VisionRx7]

yea, it was set to TDC and I used a timing light afterwards to make sure it was perfect. I'm on the way to my shop to try another CAS and Ingnitor chip.

[h3x11]

did you put in an high volumn pump, walbro...? check your fuel pressure. install a fpr if you don't have one....and check on the fuel pressure

[VisionRx7]

The car has a walbro pump. I ran it on my redtop with the stock FPR without any problems.

OK... I tried some more stuff without luck...
-CAS
-Ignitor
-Ignition harness
-Took off the tach signal thinking maybe I wired it to the cylinder #2 ignition signal

I am down to an ECU now. Could the ecu send a very weak signal to the coil and cause it to barely spark? The whole problem is that the 2nd cly's coil isn't firing. After removing the tach wiring, I fired it up and it ran fine for like 3 mins, then went back to not firing on that coil, so I don't think it could have been that wire. Maybe I bumped something near the ecu when I was messing with that tach wire and that's what caused the car to run good for a min, I dunno. I hate problems like this. I always seem to get stuck with weird problems, lol. My wiring harness is brand new from nissan also, so it shouldn't be that at all. Anybody want a 3cyl s13 for $10?

[cookie]

Coil packs are know to partialy fail , have you tried swapping them around?.

C.

[VisionRx7]

Yea, I swapped over new ones. It has to be the signal coming into the coil. What would cause that signal to be so weak?

[cookie]

Just checked on the UK site www.sxoc.com, and we have also had simular problems with faulty ignition amplifiers

C.

[VisionRx7]

hmm, the ignition amp is the ignitor chip, right? I swaped one over from my friend's car which runs fine and mine still ran bad. I was wondering about the grounds coming from the ECU... the power transistor grounds. Are they always grounded, and where do they ground out? I guess I will try to ground out the power transistor grounds from the ecu harness and see what happens.

[cookie]

I think the ignition amp is normaly bolted to the left suspension turret.

C.

[golfer17]

i just swapped an s14sr in mine, and its been running super rich lately, but even when im wot, it is still super rich until about 5k. im almost positive its because my supra turbo pump overpowered the stock fpr. you might check into an aftermarket fpr as well if u have a walbro 255 or bigger (but i know the supra pump flows even more at idle than a walbro does, so i was kind of expecting this problem).

[VisionRx7]

haha... ok... I found the problem, and I'm a retard! Well.... in my search for the coolant temp signal, I must have wired into the coil#2 signal wire and somehow got some type of signal to the coolant temp gauge. I took that wire off, and its all good now... still a little rich, but 10000x better! Thanks for all the help!

[VisionRx7]

hmm, ok... now its still running rich after that. I wonder if I have a set of aftermarket injectors in there. I've heard of these running rich like this at first though, so I will try to drive it around to clear it up.

[cookie]

check your lamba is connected.

C.

[VisionRx7]

Yea, it's pluged in. This is running rich enough that it fouls the plugs in about a mile. I'm going to start looking to see if these injectors are leaking, but it would be strange to have all 4 leak like this.

[cookie]

Swap the FPR with the redtop one .

C.

[VisionRx7]

ok... update... I tried a Nismo FPR and installed a fuel pressure gauge... well the brand new nismo I bought is leaking vacume out the top .... sooo I put the stock one back on because I was curious to see what kind of fuel pressure it was running that way... 36psi, which is normal, right?! AHHH!!! I installed a Apexi SAFC to turn the fuel down some... I leaned out my idle and the black fuel smoke went away, lol... My wideband is broken though, so I have no idea what kind of AFR I'm running. I took it out to do a rough street tune and ended up fouling my plugs again . I hate this car, lol.

Are there any differences between the Kouki s14 injectors and the Zenki's? I have a Kouki engine running from a Zenki computer/wiring harness. I forgot about that fact until right now, haha.

ooo yea.. another edit... I just remembered that I am also using the s13 MAFS... could that make the difference?

[NI_YON_Zenki]

This is Getting REAL old.. ..It's been over 3 years since these engines have made it to the cali coast. .. .

Yet ya'll still sit around & try to assist these folks in getting their cars running smoothly over the simplest shit that has ever stood over standard engine tuning. .. .

I know there are A billion topic threads covered on this one tiny situation.

The only difference is the fact the engine has a turbine. Use yah head & some patients along with a strong search pimp hand. .. .slap the fuck out of it. you might get something real useful back. .. .IMO

Stop running to the forums about this shit all the damn time.

[sideview_180sx]

^^^^^^^^^^^^HUSH

[VisionRx7]

uhh... I came to the forum for some help because I was having some trouble getting it to not run rich... I seem to have tried pretty much everything. Everyone that has posted in this thread so far are part of what makes forums great. If you don't have anything usefull to post, then why come in here and flame me about it? I'm sure you are not perfect and have had some problems at one point or another and had to ask somebody for help. BTW... I did use the search button and didn't find another situation exactly like mine.

... If you're such a genious, then why is it running so rich? It's all stock except for exhaust and such, but it is the same setup I used on my s13 redtop without any problems. The only thing I can think of now is that the MAFS is different between the s14 and s13... I did have to change the connector to plug it into it. I seem to have tried everything else so far. If that is the case, which I'm guessing it is... what should I adjust the SAFC's air flow correction by? Does anybody have an air flow/voltage scale for the two mafs?

[nrg]

s13 and s14 sr20det mafs are both different. they run different voltages. there's your problem!

[VisionRx7]

Awesome!!! Thanks!!!

[sblack13]

yes i was running a s13 mafs my car was running hella rich. Until i got a s14 mafs. If your running a zenki harness you will need a zenki maf unless you can source a kouki maf with the pigtail, since they are different plugs.