Here’s my problem, I have an S14 SR20DET, in an S13 Chassis. Got the thing running but it runs very, very rich. Rich to the point where it wont hold idle and just huffs black smoke. I have tried a million things to correct this problem but havent gotten it to work properly as of yet.
The car will only start if the fuel pump is primed but switched off which leads me to beleive I may have a leaky injector. But I am unsure. The injectors are pulsing (as per noid test) and are relatively new.
The car will run well if I switch the pump off while its running until it runs out of fuel, but aslong as the pump is on and the lines are pressurized normally the car runs rich.
I have included a list of all relevent modifcations to the SR and hope someone out there has some new suggestions.
Mechanical Info & Mods
-> S14 SR20DET w/ 5-Speed Trans
-> Champion Copper Plugs (More expensive plugs were getting destroyed; was previously running HKS Iridium Plugs)
-> Mallory 1:1 Boost Controlled Adjustable Fuel Pressure Regulator (Getting guage on monday for an accurate fuel pressure reading)
-> Walbro 255LPH Electric Fuel Pump
-> HKS 550cc Fuel Injectors
-> HKS F-CON V-Pro ECU
-> HKS GCC Fuel Injector Controller (Reads Nominal when running)
-> HKS T60 Turbo
-> HKS FMIC & Piping (Tested for boost leaks, found none)
-> KA24E (2.4L SOHC) MAF (Worked on old motor fine)
-> Fuel Return still routed through EVAP
Also, my wiring for my fuel pump has my Relay wired to the ignition instead of the ECU as I could not locate the proper pinout for the relay ground. Will this make any kind of a difference? I don’t think that my ECU controls voltage to the pump, especially given that the relay is ground triggered and most pumps are designed to run between min 10 & max 18 Volts. With those perameters voltage would be dependant on battery/alternator conditions which are not altered by the ECU.
Any suggestions would be appreciated. I will post my fuel pressure readings when I get them, but for the moment even with fuel pressure cranked all the way down I still run rich. I checked for proper connectivity of the FPR and it was accurate (Connected to return side of lines as per it being a return style regulator).
Thanks
Im not a sr expert by any means but if I can max out my SOHC mafs @ about 10psi on my kat I think your going to be maxing your out. Correct me if I’m wrong, but I think you should get a bigger mafs.
Maxing out the MAFS at idle? Dont think so.
I don’t think my MAF is the problem at the moment because at idle im not running any boost, and it still runs stupid rich.
and most of the time it will only hold idle for about 1-2mins then get fouled & die.
I can try other MAFS, but at present I don’t think its my problem. If anyone else has had similair problems with the MAFS i have a friend with an S14 SR MAF I can test.
isn’t that fuel injector contoller only for extra injectors??
if so how are you correcting for those 550cc injectors??
No, the Injector controller controls injector pulses at various RPMs from 500 RPM - 8500 RPM. It can be used to control 4 - 6 injectors and can only be used with an HKS ECU.
It is accuratley set for 4 Injectors and set for the lowest possible pulse setting at idle. The reading on the controller reads that the pulse lengths are nominal and have been retarded from the normal F-CON ECU setting. The controller will not retard the pulse lengths any more then it is already set to. I have tried to advance the timing just to see if it would make a difference, but it won’t even run if set at its normal F-CON setting or anything besides the lowest possible setting.
FYI the controller is used to adjust the length & intervals of injector pulses to lean out fuel at idle and increase fuel at high boost. That is how its used to compensate for the larger injector size.
Missed that you were running an sohc mafs on a s14sr, I’m pretty sure sasha who posts on here was running one and it was making it run like balls.
Try your friends mafs.
The MAFS is more than likely your problem. I tried running an E MAF on my S14 and it ran like complete ass. Got a 300ZX problem went away. Now I am running a stock S14 MAF right now and the car runs fine.
Get an real S14 MAF and go from there. I almost guarantee that will fix your situation. My theory is your ECU is not seeing a proper air flow count and therefore dumping assloads of fuel in. You can also try unplugging the MAF and starting it.
Also, having a fp gauge is critical with your setup, I would install the one you are getting before trying to diagnose anything further. Who knows how high the pressure is.
Where did you see that a SOHC maf would work on a OBD-II S14 SR?
Ok, got guage and fuel pressure is set to 30psi. Still stupid rich, even if I bring fuel pressure down to 10 psi, it still runs rich.
HKS told me the MAF from the SOHC would work. I think they are wrong, although I am surprised on them not trying to sell me the VPC unit my ecu should have. But at $1000CDN it will have to wait. I will grab an S14 SR maf and test it out to see how it works.
I tested the MAF for volatage and its getting juice, so I can only guess that it is not sending a signal that can be recognized by the ECU. While running I disconnected the MAF and the car didnt respond to the change at all, so for now all fingers point to MAF.
As for the car being OBD-II, it is not. Mine is still OBD-I as it is from a 1996 S14 Kouki. OBD-II wasnt until the Zenki’s ( 97-98 ). All 93 - 96 S14’s are OBD-I. And just because I fear this question will arise in the future, yes my oil cap clicks, and yes I have nuts adorning my valve cover instead of bolts.
Thanks for all the input sofar guys, were gettin closer…
YOU, my friend, need to re-build the top end.
If only you had spoken up sooner!! I was thinking of rebuilding, but I can’t seem to find anywhere that stocks the upper difibulator valve. Without that, the rebuild is pointless!!
P.S. Check the for sale forums, selling Flux Capacitor for S14 SRs
I put on a S14 MAF and everything went away. Now I just need to find an S13 speed sensor to get accurate speedo readings.
Thanks to KoukiS14 & AppleSauce for the suggestion. You saved me from driving my beater around all summer.
Only so much fun you can have with a mid 16 second Suzuki
yea that mafs will not work without an S-AFC II or some other resistor