I'm rich! Help!

[Clawhammer]

I recently put in the following to support more boost on my S15 Turbo:Z32 MAF550cc InjectorsEnthalpy tuned ECU for the above.

I've been running rich, but not this rich. Before doing the above mods I ran my GT28R at 6psi. I don't have an AFR gauge, I really need to work on that.

Anyway, I drove to Clearwater for Thanksgiving which is like a 2 hour trip. It took 6 gallons to get there. I did the above mods, and drove back after Thanksgiving and it took me a little over 11 gallons to get home.

I'm getting 12-15mpg, and the smell is awful. Apparently when you're behind me and I get on it, it looks like I'm driving a diesel and you can taste the gas lol. Also, it'll smoke unburnt gas on idle.

So I tried the unplug the MAF trick and it appears to be in working order. I haven't tested my O2 sensor yet because I don't have a multimeter that goes that low. Test coming soon. As of late my temperature gauge has not been moving. I figured since the weather got so cold and not having a front bumper, coupled with the inaccuracy of the gauge and shrugged it off. The Temp. sensor can affect me situation correct?

How is the SR setup? I only know of an upper sensor...is that all there is? Just one that sends a signal to the ecu and cluster just like the VSS does? Or is there a seperate sensor for this?

Any ideas or pointers you guys can give me?

I got the ECU from Veebee here on the forums who ran the exact same setup and says he never had problems with it, but I've contacted a tuner at Enthalpy just in case.

Other than this, the car runs great, and 15psi is amazing.

[mRodiek]

did the previous owner of the ECU have a different FPR or fuel pump?maybe the MAF is readin correct?

just throwin ideas out there..

[duffman1278]

Did you make sure you installed the injectors correctly by "popping" them into the fuel rail?

Your coolant temp. sensor could also make you run rich. (2 prong not the single prong connector)

How's your fuel pressure? Are you running an adjustable FPR?

[Clawhammer]

Previous owner of the ECU has the same pump and FPR as I (Walbro 255 and stock, respectively).

It was my first time installing injectors, but they did pop in...I guess...no leaks or anything?

I will be checking the pressure tomorrow. Just trying to get a preliminary jumpstart/brainstorm on this now.

[mRodiek]

clean the MAF..again throwin it out there. good luck!!

[duffman1278]

Check for any boost leaks and vacuum leaks which could give wrong readings to your ECU.

[Clawhammer]

Ok, what is fuel pressure supposed to be. Mine is 2-3psi...something is up...

Looked for boost/vaccum leaks but couldn't see anything.

Gonna get a wideband.

RE: Coolant temp sensor...where it? The orange connector under the intake manifold? And then there's another plug next to that? I'd like to test this.

[Clawhammer]

What should my fuel pressure be? I've got a practically new FPR from a KA...are they compatible?

[Clawhammer]

This gauge worked last time I used it, trying another tomorrow.

Fuel pressure didn't change with or without the vaccum line. Assuming it should be in the 36-40ish range?

[jr_ss]

Think FP should be 36psi without vac hooked up and 43psi with it hooked up at idle of course.. Perhaps you have a bad injector somewhere and it's sticking open pissing fuel into the engine...? Best way to check for it, Pull rail from manifold, leave injectors bolted in, key on to build/prime FP and see if one is spraying a stream not a mist.

[IanS]

Gonna get a wideband.

RE: Coolant temp sensor...where it? The orange connector under the intake manifold? And then there's another plug next to that? I'd like to test this.

Those are the temp sensors.

One is the sensor that tells the ECU what the coolant temp is, and the other is the sender that works the gauge. I don't remember which is which, I would just tell them you need the one for the ECU.

[duffman1278]

^^^^ Its the one with 2 prongs that goes to the ECU. The single prong connection is the one that goes to your cluster.

[Z28ricer]

Im pretty sure you've got the pressure gauge hooked up wrong. The feed into the gauge should be tee'd off the pressure hose coming from your fuel filter and going into the rear side of the rail, it looks like you've got it between the tank and the fpr, if thats the case and you've got 2 PSI there, you might just have a blockage in the return hose somehow and thats causing the fuel pressure to rise.

This gauge worked last time I used it, trying another tomorrow.

Fuel pressure didn't change with or without the vaccum line. Assuming it should be in the 36-40ish range?

[nzmoman]

if you are running a BOV. be sure to check the vacuum lines there and make sure there is no leak on the lines and the BOV. That will get you running rich as well.

[duffman1278]

http://www.240sxforums.com/for....html

[Clawhammer]

JR: Got it, thanks. Gonna pull the rail anyway to make sure nothing is leaking past the orings, pretty sure they're fine though.

FBI: I figured those were it, thanks.

Tommy: Doh! Yeah I had it between the tank and the FPR. Will test again!

Nzmo: I went over my vaccum lines and everything looks kosher. Whenever I have a leak it's immediately apparent as my BOV stops working and compressor surge raises a red flag.

Duffman: Thanks for that link, that is gonna help a ton! And all your other help.

I looked up the KA and the fuel pressure is the same so I'm gonna put the new FPR I have in when I pull the rail to test for leaks. Figure I might as well put a brand new one in that is just laying around, the current one has probably been in there for like 18 years lol.

In that link that duff posted the guy mentioned the AAC, I was curious about that because it was bad on my KA. He says where it is on the blacktop, does anyone know if this is the same on the redtop?

Out to the garage I go!

[Clawhammer]

Fuel Pressure: 39 and 49-50, vaccum on and off respectively. What do you think?

Found the AAC, it's under the runners on the intake mani...hope I don't have to remove that!

About to check for oring leaks.

[Z28ricer]

Fuel Pressure: 39 and 49-50, vaccum on and off respectively. What do you think?

Found the AAC, it's under the runners on the intake mani...hope I don't have to remove that!

About to check for oring leaks.

Make sure to check for leaks at the vacuum hookup on the FPR itself, i've seen them when bad, leak fuel there, gets sucked back into the manifold through the vac hose.

Does it only do it when hot, at all times, only when cold ?

[Clawhammer]

Rich at all times. Put the new FPR in and same readings.

Vaccum leaks: checkLeaking injectors: checkFPR: check

Next I guess I'll test my CTS. I'm leaning more and more towards the AAC/IACV...I've always had a high idle...dammit I don't want to replace/clean that thing. On the way back to Gainesville in rush hour Tampa traffic, everytime I'd creep forward a little and push the clutch in it would die. Not getting enough air/too much fuel due to a faulty IACV? :/

[Z28ricer]

Your IAC isnt going to cause you to go rich.

There are only a few things that are going to do it, injectors themselves. Pressure spiking in the fuel rail. MAF, tune.

How is the idle ? Do you have a compression tester to check that ?

Rich at all times. Put the new FPR in and same readings.

Vaccum leaks: checkLeaking injectors: checkFPR: check

Next I guess I'll test my CTS. I'm leaning more and more towards the AAC/IACV...I've always had a high idle...dammit I don't want to replace/clean that thing. On the way back to Gainesville in rush hour Tampa traffic, everytime I'd creep forward a little and push the clutch in it would die. Not getting enough air/too much fuel due to a faulty IACV? :/

[Clawhammer]

According to the link duff posted:

"AAC/IAC: The AAC valve (Auxiliary Air Controller) takes in the air ratio and puts it through the computer keeping a tab on how much air is entering the intake. Mostly it is the ECU's main idle control system and can deff control the A/F ratio. Sometimes this sensor can get clogged with carbon and cannot get a good reading. To get a new one you’re looking at $170-$299 (ouch) so cleaning it might be a more cost effective way to attack this problem. I have a 94 Black Top so mine is located under the fuel rail towards the firewall. It does take some work to get at it but some Carb Cleaner and a fine brush should do the trick.*One thing to remember!There is a gasket that needs to be replaced once you take off the valve itself. "

[duffman1278]

Did you replace it? Because you have to replace both the intake manifolds gasket and the IACV gasket.

Positron show's how he cleaned his in his LOOOONG thread of his SR build.

[Clawhammer]

No I didn't have any time to do anything today. It'll be a little while before I have the time to do that. I know about replacing the gaskets.

I want to test my coolant temp sensor now. What numbers should I be getting hot and cold?

[Z28ricer]

I dont know what kind of crack the person who wrote that article was smoking, but the IACV is for nothing but idle control, it allows air to bypass the throttle body and enter the engine, to control the idle. The mass air sensor is what meters the air entering the engine.

[IanS]

According to the link duff posted:

"AAC/IAC: The AAC valve (Auxiliary Air Controller) takes in the air ratio and puts it through the computer keeping a tab on how much air is entering the intake. Mostly it is the ECU's main idle control system and can deff control the A/F ratio. Sometimes this sensor can get clogged with carbon and cannot get a good reading. To get a new one you’re looking at $170-$299 (ouch) so cleaning it might be a more cost effective way to attack this problem. I have a 94 Black Top so mine is located under the fuel rail towards the firewall. It does take some work to get at it but some Carb Cleaner and a fine brush should do the trick.*One thing to remember!There is a gasket that needs to be replaced once you take off the valve itself. "

Whoa whoa whoa.

Hold on a minute. The MAFS is what meters air entering the engine. That being said, I dont know as much about the S14 SRs, there may be some kind of some sort of fuel control system after the throttle body, though I doubt it.

The truth of the mater is, even if it does have some sort of system like that, if would only effect the engine at idle and part throttle. The engine runs in open loop mode, using preset injector pulse widths, it ignores almost every sensor.

Have you checked for ECU codes?

[Z28ricer]

Right now you need to do a compression test.

Then set the fuel pressure gauge up on the car tape it to the windshield, and watch pressure while you are driving around.

You should see the pressure rise 1 psi per lb of boost, over the vacuum off pressure reading.

IIRC the vacuum off reading should be 36 psi which is a good bit lower than what you said it was.