Just wondering if anybody has any thoughts on this problem I've been having.

For a while now, the car runs completely lean when going full throttle at lower rpms. When at WOT at higher rmps it's just fine. Only about 2500 and lower. There's a very loud knocking noise sometimes with it (no clue where it's coming from though). Other then that there are no other problems at all. Injectors seem to be fine as well as all the other fuel related parts. Any ideas? And why it would just happen at low rpms?

Jen
95 Eagle Talon ESi
97 Mitsubishi Spyder GS-T
90 Eagle Talon TSi AWD
91 Mitsubishi Eclipse GSX
91 Mitsubishi Eclipse GSX

Spyder For Sale:
http://www.geocities.com/dsmxtsi/Spyder.html

Well the knocking is most likely from the lean condition in the engine. As for why it does that in WOT at low rpm's I am not sure. So if you stay in the throttle at the low RPM's does it come to life above 2300, or have you not stayed in it? Which car are we discussing here anyway? How long has the fuel filter been in there? I would assume that with the lower FP in the lower RPM range it would be harder to get through a partially clogged filter.

Talking bout the NT :)

When it's lean at WOT, it stays lean, till I let off. It will usually stay lean even when I reach higher rpms. When I let off and get on it again it runs fine. Fuel filter is pretty new. It seems like the problem started when changing the timing belt. We already double checked everything and can't seem to find any obvious problems related to fuel or anything else.


Jen
95 Eagle Talon ESi
97 Mitsubishi Spyder GS-T
90 Eagle Talon TSi AWD
91 Mitsubishi Eclipse GSX
91 Mitsubishi Eclipse GSX

Spyder For Sale:
http://www.geocities.com/dsmxtsi/Spyder.html

I would throw out ideas for you but people move away have a kid and never call so I can’t help

I'd be more inclined to think, MAP or Oxygen sensor, gone bad, possibly an idle air temp sensor or something like that...



15.9 @ 86.7mph

Una Salus Victus.

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>I would throw out ideas for you but people move away have a kid and
>never call so I can’t help

People move away, have a kid, move again and never have time to call... :) Cody already talked to you about that problem, didn't he? I'm not really too concered about it since I don't ever get to drive my car anymore, but he bitches everytime it happens so I thought I'd ask around.

BTW, when will you finally update your sig pic???

Both oxygen sensors were replaced when we did the timing belt. Next? :)

Jen
95 Eagle Talon ESi
97 Mitsubishi Spyder GS-T
90 Eagle Talon TSi AWD
91 Mitsubishi Eclipse GSX
91 Mitsubishi Eclipse GSX

Spyder For Sale:
http://www.geocities.com/dsmxtsi/Spyder.html

a MAP sensor may be able to do something like that. it may not be the sensor but perhaps one of the connections or a messed up wire. or any other part of the speed density system in the car (it is a 2gNT right?)a really bad thing would be if the timing belt was installed incorrectly and the knocking sound you hear is a valve getting banged up, or detonation due to incorrect timing maybe due to the belt slipping at WOT.

Yeah if there are no issues with the fuel, then sensors would be the next place to start searching. As long as you could easily remove and re install the pin on the tensioner when you did the t-belt then it should not be slipping. Check the map sensor. And what kind of 02 sensor, the stocker or the Bosch? I have heard the bosches are sometimes not accurate and they die quickly on some of the guy's that use them.

Hello, this is Cody, Jenni's husband. I just jumped on here and noticed her post.
We don't think anything is wrong with the fuel system as it gets 30 mpg with the a/c blasting everyday on my home. Car runs absolutely perfect except at WOT up till 4K rpm, anything past 4K rpm at WOT and it runs like a champ. I have been suspecting a bad sensor but the c/e light hasn't been on since the timing belt install a few months ago, so I haven't bothered checking them until today.
At the time we did the timing belt we also replaced the front o2 sensor with an oem unit and also replaced the gasket for the cps since it was leaking some oil through there.
Today I only had time to check the tps and cps with help from Chiltons. The tps checked out just fine. The cps is where I have some questions from the Chiltons manual. First it says to disconnect the cps harness, turn ignition to ON, and check at the harness side. I checked the voltage from pins 1 and 3 and the voltage is within spec, it also had continuity which the manual says it should have. So then the manual says that if the voltages are within spec and there is continuity, to replace the sensor. I don't understand this. Why would I replace the sensor if the voltages and resistance checked out fine, and how does it know the sensor is bad if it checks the harness side? Does the ECU store the values and this is what I'm reading at the harness? Sorry about this but I'm a little numb on most electrical troubleshooting issues. It would somewhat explain the WOT trouble, but the c/e light is NOT on so I'm hesitant on believing the cps needs replaced. I pulled the cps off to check it out and it appears to still have some oil on it, could oil soaking onto the face of the sensor cause it to go bad? I assume it would. This is a 95 2gnt with minor mods: cat-back, intake, underdrive pulley, and new Accel plug wires.
One last thing, the rear o2 sensor wires were dragging on the ground for a while and became loose, due to the H&R Race springs. I then cut the wires and tied them up under the chassis but kept it grounded to not throw the c/e light, the sensor itself is still in the pipe. I couldn't get the sensor to budge loose so that's why I haven't installed the new rear o2 sensor yet. I don't think this has anything to do with the WOT issue since it only reads if the cat is functioning properly, but I figured I'd throw this in here anyway just in case.


Cody
95 Eagle Talon ESi
97 Mitsubishi Spyder GS-T
90 Eagle Talon TSi AWD
91 Mitsubishi Eclipse GSX
91 Mitsubishi Eclipse GSX

Spyder For Sale:
http://www.geocities.com/dsmxtsi/Spyder.html

The CPS is going to help control spark timing, shouldn't effect lean/rich really. I think you need an oscilliscope to check it properly anyway.

Did you check out the Map?

What about something as simple as a clogged injector?



15.9 @ 86.7mph

Smooth idle? We don't need no stinking smooth idle.

Mods List:
http://highlander.dsmpower.com/sig.htm

How are you determining that you are running lean? Do you have a EGT?

>How are you determining that you are running lean? Do you
>have a EGT?

We have an a/f gauge that pegs in the bottom red led, plus it loses most all power. The knocking noise from detonation happened only once, though we don't go full throttle under 4K rpm anymore to avoid that.

>>clogged injector<<

I once thought it was an injector, but since it drives perfectly normal under any other circumstance, and gets 30 mpg with a/c, I have since ruled out the fuel system. Although that's not saying it isn't the problem. I'm going to check out the MAP sensor soon. Jenni's dad needed the ohmmeter yesterday so I wasn't able to check all the sensors.

Cody
95 Eagle Talon ESi
97 Mitsubishi Spyder GS-T
90 Eagle Talon TSi AWD
91 Mitsubishi Eclipse GSX
91 Mitsubishi Eclipse GSX

Spyder For Sale:
http://www.geocities.com/dsmxtsi/Spyder.html