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[mitsu nightrider]

ok, i have a problem. my car is burning rich, three reasons i know why it is, 1) every week i can wipe out enough carbon build up out of the tailpipe to start a business selling it. 2) my autometer a/f guage is deep, the closest bar to completly rich under full load at 14 psi. 3) my car is not as fast as it should be.

now, some background info first, i just converted my fwd non-turbo to turbo. I ordered a jdm engine and got all the parts i needed from a 91 eclipse awd turbo, manual. everything is working great except that i am burning a little rich.

things i've checked. its not a clogged return line, fuel pressure regulator. not a bad o2 sensor. i did a diagnostic check and everything is fine. my fuel pressure is a little high but thats because of the non-turbo fuel pump, i'm pretty sure. Chiltons and Hanyes manuals state that my pressure should be around 28psi with the vaccum hose on and about 36psi with it off. WELL, I'm sitting at 34psi and then 41psi with it off. i thought my fuel pressure solenoid could be at fault but i was just assured that isn't the problem

NOTE: I bought a walbro 255HP pump about a two weeks ago and i took it right out, it practicly bathed my engine with fuel...so so so slow, which is uncommon that it would be that rich...it seems my ecu cant lower the pulse width for some reason...bad injectors?

where is the problem?

thanks

[Rdy2race]

because you did a swap nothing can be taken for sure. we do not know your level of knowlage. All I can say is this with the comment that is #2 that your Autometer AF gauge is pinned shows us that you may know a good amount but not nearly enough

The gauge MUST be pegged. the reason is that Turbo cars like it rich. they NEED it to be rich. on pump gas you will never run 14.7:1 AFR as this is so hot that you WILL melt a valve if not worse.

factory tune is .98 on the o2 this is vry rich but stops it from melting down. You can tune to .90 on pump gas and leaner to .78-.72 on leaded race gas. The Autometer AF gauge last light only comes on at .90 so you have no idea if your at . 90 or .99V IMHO any AFR gauge that uses lights it worthless on the street but can be usefull with leaded gas that allows you to run much leaner. ( but lead kills o2's )

What injectors are in the car? What boost levels are you running? What mods are done to the car? carbon buildup can be from many other things other then tuning. under the "things I have checked" how did you go about this? Who did your T belt?? why does the car have a NA FPR on it? That pressure is fine you should not hae a prob at that all injectors are rated at 43 PSI rail pressure. but like you said stock is 36 no vac.

the ECU that you installed is it in a 91 car? did you swap in the turbo MAS??

I could go on but I won't :D

BM-

[mitsu nightrider]

I don't know everything, or else i wouldn't be posting this. I do know a few things though. Like, i know the a/f guage isn't very accurate, but i got curious when a friend of mine is running the same psi as me (14psi) and his guage doesn't go as deep as mine, and i we both have the same grounded spot.

I have the stock 450cc injectors, 14psi, k&n filter and 2.5 exhaust all the way back, i did my timming belt, i have a stock turbo fpr...all turbo parts are out of a 91 eclipse turbo awd manual.

I got both the ecu and mas out of the 91 turbo.

Here is what i think it could possibly be. When i got all of my parts from the same 91 eclipse i noticed something funny, but thought little of it at the time. everything was all connected...all clips on the wirring harness...except the ecu, it wasn't connected. It also says in black marker "ecplise auto", as if someone switched them. now i thought oh crap, auto turbo ecu's are programed to control a whole different set up such as 350cc injectors and a higher fuel pressure which is oddly the same pressure i am at. The only reason i dont think that is the problem is that my ecu has the same numbers on it as the on out of my friends car which is a 94 eclipse awd manual.

Someone please tell me how i can find out if i have an auto ecu. or if thats not the problem, any insite will be very helpful.

thanks for your reply

[Edited by mitsu nightrider on 07-17-2001 at 12:00 AM]

[Rdy2race]

well the board could have been swapped. That would answer that if that is true but no way that I know of off hand. you need to look for markings on the board it self.

your friend is to lean if he is not peaking out the gauge. Don't base this on that also as the o2 it self could be the problem with his/her car. Another thing is that the fuel pressure is to high. Why? if you have a turbo FPR on it there is no reason it should be so high. All AF gauges and digital MM that are used to check the o2 shouold be grounded to the ECU.

I would look in to the high pressure and then look in to the cars ECU. have some one with a pockloger/TMO scan tool or some sort of scannign tool look at the car and see where the inj pulse with is at. Idle should be in the 2.05-2.50 ms range. Then what are the fuel trim levels at?

Does the o2 cycle at idle? Try a ECU swap with a friend? Ummmm.... reaching here for more........

WAIT what year is YOUR car??

Did you run a new knock sensor wire?and if so is it shielded??

If your car is a 90 and you put in 91 + parts this would be the problem.

when you got the motor what did you need to do in totalmake it long winded as this will be the only way to tell.

BM-

[mitsu nightrider]

thanks for the info. I think it could be the ecu, there are yellow paint marks on all the screws, DUH...it is very likely the board was changed. I'm pretty sure the high fuel pressure is from the non-turbo fuel pump, which has a little higher pressure with less volume, but i have a walbro dying to go in. i did get a new knock sensor and yes i sheilded it. i will put my friends ecu i tonight and i'll let you know how it goes.

thanks a lot

[awdan]

Now you have my attention. I just swapped in a 92 motor into my 90 GSX and I'm pretty sure that I used the 92 knock sensor, I will check. Right now I'm breaking in my ACT 2600 with no boost(disconnected the flapper arm) but have not noticed any significant carbon or overly rich condition. Tell me why it would make a difference.

Thanks,
Dan