HISSIN, need you again, checked some sensors.

[CManT1914]

HISSIN, you know the deal, for others here's what's going on. I've been having problems, I pulled the codes and got 181 and 189: Fuel system at rich adaptive limit at partial throttle / system lean. HISSIN said that I needed to check all my sensors to make sure they were in spec. So I tested my ECT and IAT sensors.

Me ECT sensor had a voltage supply of 4.5v, so the wiring is good. It had a 3,500 ohms resistance, which is right on par, so I think I can rule out the ECT as being a suspect.

My IAT also had a 4.6v supply, so good wires. But at normal temperature, it was reading 19,000 ohms! It should be like 2,000 according to the Haynes manual. It DID have some gunk and crap on the prongs, so I cleaned it off, but didn't check it again.

EDIT: I checked my MAF, it read 5.6v engine off. My battery died so I couldn't start it to check it at idle though.

I didn't see any info in the manual about testing the IAC sensor, so I left it alone, anybody have information on that?

I didn't have time to test the O2 sensors, as I was doing this on my lunch break, but HISSIN, you said under WOT they are ignored anyway, well under WOT, it still runs like crap. So I don't THINK it's the O2's. Anymore advice?

 

[CManT1914]

BUMP

Okay, I checked my timing, it was fine. So I've checked every sensor I can think of, what else is there? Since I cleared the PCM the other day, the check engine light hasn't come back on, but it is still running like crap. I pulled the codes again, but I got the all clear for KOEO, Continuous Memory, and KOER scans. Anything else I can do?

 

[mackey]

Pretty sure the MAF should max out at 5V on the stock computer, so something is definitely off.

 

[HISSIN50]

i dont know a whole lot about MAF (88 GT vert is SD and i have not tinkered with the SN's MAF much). i *thought* that the MAF got 12 volts, not VRef (5 volts). charging the battery back up and checking again would help.

do you know what ambient temp you tested the ACT and ECT sensors at? the ambient temps matter a lot (most shop manuals assume something around a 70* ambient temp while testing). as temps go up, ohms go down. the resistance readings should be done with the electrical connector disconnected.

testing the IAC is a pain. it is often easiest to be able to measure the square wave. there are some simpler elec tests, but i think they might be SN specific, so ill leave that to others in here.
also, if the car's cold idle was really poor or poor under load, i would look further into the IAC. it should toss an upper or lower limit code if it is bad.

i agree with your O2 thoughts.

the MAF thing is what i would tackle next. sorry to not have better ideas for ya. good luck.

 

[CManT1914]

Well I found my Pro-M MAF I had laying around. I put it on with my stock air inlet, and holy CRAP does the car run better now. I guess it was my MAF after all. I never did an ohms test on it, (just checked the supplied voltage) so I assumed it was good, especially since Ford just replaced it a year ago. My factory MAF went out last March, and that was before I knew much about cars, so I just took it to Ford (cus I didn't know why it was throwing the CEL and why it was running bad). Well they said it was the MAF and replaced it. Since it was just a year ago, do you think that the MAF might still be under warranty? Or do you think it would be a bad idead to even try and get ford to do anything about it?

 

[HISSIN50]

LOL, yeah, i would not bother with trying to get any warranty out of it.

glad to hear it is running better.