Typhoon33

my 93 fd sat for about 10 days and now it runs terrible. idle is smooth and up to about 3500 its sems to run fine. when you get on the gas hard or when revs get over about 4000 the motor turns to crap. sputters violently and kicks and even cuts out entirely for a moment from time to time. smokes quite a bit as well.

so far we have checked vacuum hoses and everything seems fine. someone said that it may be an o2 sensor and that is next on the list to look at. that theory may have some credibility since i did run some leaded race gas before the car sat for the 10 days.

any other ideas?

DaleClark

iTrader: (55)

Have you checked the vacuum line to the MAP sensor?

Also, look at the sensor check in the PowerFC - you can tell pretty quickly if you have any inputs or outputs that aren't happy.

Dale

Typhoon33

yep, the line there is fine. checked the ones under the black plastic box too and all is tight.

can you guide me through the sensor check? im not familiar yet with the power fc functions

thanks!

SlingShotRX7

Could be bad tank of gas.

RotaSpinna69

iTrader: (10)

Sounds like the symptoms im having also. My Power FC will be here on Monday so I'd like to know how to get to the sensor check screen also...

DaveW

Doesn't sound like a bad O2 sensor - the ECU doesn't use O2 sensor data at WOT or high loads (it runs open loop), it only uses it at low rpm and loads, and you say it runs OK under those conditions.
Bad gas should also make the idle, etc., bad.
It could be a blocked fuel filter, or other fuel-supply problem.

lennie_hughes

sounds like bad gas, could be water in the tank.........

when was the last time you changed the fuel filter?

TwinTriangles

What is the temp. outside where you live ? Are you possibly hitting fuel cut or is it sputtering and stuff even when not under boost ?

moehler

iTrader: (12)

I don't have it in front of me, so this might be 'slightly' off .

1) Hit back until you hit the main screen; should have three main titles on it - Display, Settings, and "other" (again I forget exactly what these are called).

2) Go to the "other" section

3) Click on sensors check option

This will tell you if a sensor is on or not, and what voltage it is pulling.

Typhoon33

humid and hot. about 85 degrees.

when you give it gas gradually it does it at about 4k rpm. if you give it alot of gas at once it does it right away. feels like the first turbo is coming on but not the second. it does it under load and sitting still.

Gas was really low so we put about 10 gallons of regular high octane. symptoms didnt change much. filter hasnt been changed lately - will look at that as well.

will also check the power fc now.

thanks

RotaSpinna69

iTrader: (10)

Did anything come up? Cause i'm having the same problem after doing the non-sequential mod. I have changed the fuel filter and it is still a problem. I'll also be checking the fuel pump soon if not buying a new one.

SlingShotRX7

Just a FYI..

Map sensors can go bad..

not sure how to check.. but good luck

Typhoon33

havent had a chance to get into it yet. i will update when i have tried some of the suggestions given.

RotaSpinna69

iTrader: (10)

If I find anything out also, I'll post...

Typhoon33

so far tried the o2 sensor. no change. grrrrrrrr!

RotaSpinna69

iTrader: (10)

Well as of a week or so my car has been at MazMax here in Houston. I'm going to drop by tomorrow and see how things are going, if the problem is fixed or they have found out something, i'll post...

Typhoon33

Oh yah, fuel filter is ok as are the fuel lines.

Typhoon33

Could something have happened during clutch replacement to cause my problem?

Red-Rx7

Did you check the sensors on the PFC?

RotaSpinna69

iTrader: (10)

Well i went to check up on the car today and you might want to get your fuel system pressure checked. They showed me that the car started up fine and pressure was good, but when you turn the key off, the pressure drops down to zero automatically. Which is strange to me. They said it might be a problem with the fuel pump or at least its resistors. But that is just what they told me. I guess we'll see...

Typhoon33

my tech called and says that they just fixed the problem. he says that they were doing the sensor check that was recommended and saw that the PIM setting was at "option 4" - when they put it back to "normal" the car runs perfectly.....

I know from the power fc manual that PIM is the pressure sensor. anybody know what option 4 is or why it would have caused my problem? How did it get to that setting?? Strange!

RotaSpinna69

iTrader: (10)

Well I hope this is the problem with mine too. I just got my Power FC so we'll see what happens when I go through the sensor check. By the way are you running non or sequential twins, single?

Thanks,

Andrew

Typhoon33

sequential twins.

good luck.

rjeremy000

You know, I have not driven my car in two weeks either and then last night I got in my car and took it for a little spin. I seem to have THE SAME PROBLEM!!! Argh, after waiting for some decent weather (and the time to drive the car) for two weeks and now it's killing me to think that I need to bring the car back to the shop.