BringIT

My setup
98 JRSC 6psi GSR
DSM 450
SMC 500
Walbro 190
stock fpr
new OEM fuel filter, wires, rotor, dist. cap
NGK BKR7E plugs are approx 5000 kms, still like new
10 BTC at the dist.

smc set at idle 24
1-2k ~ 23
2-4K ~ 22
5-6K ~ 21
7-8K ~ 20

I keep getting this damn CEL 45. Can't figure out why the car is running so lean.
On the stock fuel pump, looking at the plugs
cyl1 decent black (fine)
2,3,4 black with some white specks/patches (lean)
idle fp at the fuel filter 42

car drives pretty well .. but after every 2nd or 3rd start I get CEL 45, or sometimes when I'm just crusing. But I will get the code every day at least once.

I installed a walbro 190 tonight idle fp now at 46-48
drove around for about an hour not in boost. checked the plugs
cyl 1,2,3,4 perfect black and light brown
drove around for another 15 minutes.. stopped the car.. started the car CEL45!
on my way home I did 1-2 WOT pulls and checked the plugs
cyl 1,2,3,4 black with white specks/patches (running lean)

checked timing.. 10BTC still..
The car actually is a lot more responsive with the walbro 190lph .. dunno why but the throttle response is much better and the car is a lot smoother.

I don't understand what could be wrong.. any suggestions?

BringIT

oh still running stock obd2 p72 ecu..
obd1 p28 on it's way.

I'm planning on having it custom chipped and tuned on the dyno once the ecu/harness arrives. But until I get everything together, I want to figure out why I keep getting this code. No black smoke puffing out, I know I'm not running very rich. But at -20 that should be a lot of fuel.. but I'm running lean?

Sonny

The code 45 is thrown for a rich or lean condition. It could be either one. The only real way to tell is to check the short term and long term fuel trim, but you'd need an OBD2 scantool or something like Hondata.

With that upgraded pump, you're probably running a lot more fuel pressure at idle than with the stock pump (a common problem with the upgraded pumps).

My guess is that the ECU is throwing that code because you're running too rich. Try adding fuel and see what happens. Make the change big enough to be noticeable.

Sonny

Mase

honestly, I wouldnt boost until you can get a wideband on the car, its not good to guess. also, dont forget detonation can be caused by not only lean conditions, but also too much or too little ignition timing.

as for the fuel pump, OEM fuel pumps work fine to atleast 300 whp. (I ran a oem fuel pump for years w/ 550cc and never had problems )

sneakypete

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mase &raquo;</TD></TR><TR><TD CLASS="quote"> OEM fuel pumps work fine to atleast 300 whp. (I ran a oem fuel pump for years w/ 550cc and never had problems )</TD></TR></TABLE>

Very true Mase. A lot of people upgrade their fuel pumps when they don't need to.

BringIT

I just wanted to ensure that the problem isn't a result of a clogged fuel filter or the pump not pushing enough fuel. I had the oem pump on since I installed the JRSC last month and have read many posts about how it's not necessary. I didn't think it was the pump, but if there's detonation evident on the plugs I wanted to eliminate all the fuel components before looking at something else.

I'm thinking this issue is related to timing now.. I am running 94 octane gas, not much I can do about timing except retard more.. I guess last thing to try is to pump more fuel in with the SMC to see what happens or wait until I can get on the dyno.

Any idea wether the cold weather can cause the car to run lean?
At night it's -8C I think that's like 26F and today it's -18C with windchill like 16F?

Sonny

Are you still running the JRSC IAT enrichment relay?

Sonny

BringIT

no JRSC IAT relay. I'm running 450's and SMC.

I've been taking it easy on the car.. did not go into boost once and still got code 45. It's been so cold out, havn't been able to play with the SMC. I should be getting the car on the dyno at the end of the week if my ecu arrives this week.
I'm hoping that the SMC just isn't set correctly.. I've been having problems with it not retaining the correct settings.

Rory Breaker

I would assume it has something to do with the SMC. How did you tune the fuel delivery originally?

I want pics/vids and dyno numbers when you get them dude!

BringIT

Guestimation .. lol I set it at -35 across the board because that was the default SMC settings and the car idled but it was running very lean so I went to -30 then to -25 .. and that's where I'm at now..

I think I'm going to try -20 today and see what happens.. it's a mild -11C/12F today In another post I was writing abou how certain rpm settings were not being saved.. I'd punch in -24 and the verify would read -22?? It did this for a few of the points so I dunno what's causing the car to run so lean.. my settings or the SMC...

for sure.. I'll take pics once I get it on the dyno.. I'll try to get a video camera too.. I'm dying to see the numbers too..

I did notice that when I did boost on these cold nights.. the boost gauge would read 7-8psi

It was funnier watching the look on the face of this guy in a 350Z trying to outrun me .. where u going dude? nowhere.. that's right.. lol

TOFU.man

you can check it with a passenger in the car. pull some insulator off the wire at the ecu that comes from the o2 sensor, get your passenger to put a volt meter on it .90 volts - 1.0 volts is plenty of fuel you wont have anything to worry about but make sure the person with the voltmeter looks for sudden drops in voltage or sparatic movement 1 sec lean will throw the CEL. good luck.