If your knock sensor voltage is that high, then you're either measuring the wrong terminal or something is shorting out the knock sensor signal.

Did you see the error code for the knock sensor? If you have a bad knock sensor, it'll be a sticky error and remain until you clear it (drain system after disconnecting to battery).

I recently had a short on the knock sensor to GND. I measured the voltage when I fixed it and I saw around 2.5V (close to nominal).

J

 

The error code doesn't come up unless I unplug it, but unplugging it has no effect on the timing. AJatx, how were you testing your knock sensor? I need to know how to do this right.

 

You mentioned that you had a charger hooked up and when the prob started (lower rpm's) the charger was working harder. Well i've only got a 1st gen, but the alternator cuts out at lower RPM, all by itself, may be what happened.
And I also had a prob, worse than what you have... the engine just died completely. Broken wire leading to the air flow meter. Look through the wiring harness and see if there are any broken / loose wires, or spliced connections. Mine was a spliced connection that was crimped and corroded through. Another idea, maybe why the wiring harnesses go after a while.

 

Ok, I hooked up a friend's Power FC and have all the readings. Only problem is I'm not quite sure what they all mean. Maybe I can get some help. Here is a readout of the whole etc. screen. "G" stands for when the engine was running properly, and "B" stands for when the engine was bogging. The first reading is with the key on and the engine off. The second reading is with the the engine idling properly, and the third reading is with the engine idling all gimped up. I have NTP and NTR written for one reading, I'm not sure which is right. For the switches: "o" is the open circle(off I presume) and "*" is the filled in circle(on I presume).

Sensor___KeyOn_G__EngineIdling_G__EngineIdling_B
PIM______2.65______1.01____________2.34
VTA1______.41_______.41_____________.40
VTA2 _____.88________.89_____________.87
VMOP____1.05_______1.17____________1.26
WTRT_____.31________.48_____________.49
AIRT______.86________.94_____________.91
FUEL_____1.64_______2.75____________3.08
O2S______.07________.82_____________.05
STR_______o_________o_______________o
A/C_______o_________o_______________o
PWS______o_________o_______________o
NTR(NTP)__o_________*_______________*
CLT______o_________o_______________o
STP______o_________o_______________o
CAT______*_________o_______________o
ELD______*_________o_______________o
HWL______*_________o_______________o
FPD______o_________*_______________*
FPR______*_________o_______________o
APR______o_________*_______________*
PAC______*_________o_______________o
CCN______*_________*_______________*
TCN______o_________o_______________o
PRC______*_________o_______________o

The O2 sensor was jumping all over, but That is not the problem, because it does the same thing in open loop mode.

The knock sensor is fine. It was reading 20 at idle and 66 while reving.

While the engine was bogging down at idle we looked at the timing, and it was going crazy. It was bouncing from 6/-4 to 3/-7 to 1/-9 at times it would be at -5/-20

but when it lifted the idle up some it was 14/17

and at one point -25/-25

There was also a point when the idle was bouncing up and down and the injector duty cycle would drop to 0%
But while driving it was around 50% with moderate throttle.

Another important note is that when the idle was bogging and bouncing, the APR and PAC switches were going on and off repeatedly.

I'm going to do a search for what all this means, but does anyone have any ideas as to what this could mean?
I talked w/ someone at Tripoint yesterday, and he said that it could still be a bad leading coil even if it tested ok.
Much thanks to Rodney McFarlin for the PFC and help.
Any other help is very welcome.

 

Sorry that the table is all whack. I'm going to try to fix it. Just hang on.

 

That might be better.

 

Check the main fuses. My FD blew an AC fuse and caused similar symptoms.

 

This is insane!

I would call every single rotary shop and see if anyone has ever dealt with this problem. I know it could be many things but maybe, just maybe someone has dealt with this a few times.

 

GsrSol, I've been doing that for the last few weeks, Chris at RP is just telling me to drive there or to Pettit. The folks at Tripoint and Mazdatrix have been quite helpful. I'm going to try a friends coils in a few days to see if that helps.

 

Power FC owners, are my readings normal? What's the deal with the port air control and air pump relay switched flickering?

 

What is the PIM sensor? Is that the MAP sensor? That one changed a lot between your good and bogging readings.

 

The reason the MAP sensor was changing is because the vacuum dropped to 10 inhg. I pulled my plugs and they look different between the #! and #2 rotors. The #1 plugs look kind of shiny, and the #2 plugs look like they have a matte finish. I'm going to try to borrow a digital camera.
I posted this in the Power FC forum, and someone mentioned to test the coils with a voltmeter. My only problem is that my voltmeter won't test that high a voltage. Does anyone know what voltage the coils are supposed to put out? I might be able to find a good meter at work tomorrow.

 

I don't know if this is abnormal, but with the engine idling crappily, I put a timing light on, and on the #1 rotor trailing the mark was lined up. The #1 leading was advanced a little. But then I put it on the #2 trailing and I could not even see the mark. It had to have been on the bottom. This might be normal, but if it's not, please tell.

 

Sorry I saw this so late:

Check your clutch sensor. I've been down this road before. It's dead easy to check just a 2 pin s/c o/c connector on the back of the clutch pedal arm. It's cheap it's shitty and they ALWAYS fail.

Apparantly the neutral switch on the gearbox can give the same symptoms but I've since switched to an EMS computer so I don't have to worry about that crap

-pete

-pete

 

rpm pwr: the pfc screen tells you the live-time status of the clutch and neutral switches, and im sure he's checked that already, since it is so easy to monitor with the pfc. on his table, the neutal switch was engaged and the clutch open for both normal and bogging situations, that's normal for idle without the clutch pressed in. good suggestion though.

p'cola fd: damn dude, i think im having the exact same problem as you. nobody seems to have experienced this before, or something. i hope you find a solution to the problem really bad. your mechanical insight and motivation both seem to be like 100 times better than mine are, so i am following your problem very closely to hopefully find a solution for my own idle problems.

 

forget about the timimg. With the ign ctr function on with the PFC it will violently adjust timing at idle to keep a good and steady idle, that is why you saw it stabalize when you brought the rpms up. checking the timing is pointless with the ign control fucntion on. to check timing at idle, just switch off that fucntion in the etc menu of PFC and monitor it in view mode.

your vta2 readings which is tps,(I think narrow range) is a litel low, it shoudl be just slightly less than 1 at idle once car is warm, and above that when cold.

your charge control switch is on, which is good, but check to make sure it is pulled in as well, that pFC reading only tells you that electrical signal is sent, not that it is actually working.

the port-air switches, etc, just mean that your airpump is working. generally though it shoudl only switch when you give it a little gas. however, pFC willd do all sorts of stuff to try and get good idle.

you said G was when it was idling properly, was thins after a cold start in because of which the idle were high, then they settled down and started to bog?????

 

Thanks KZ1. That was very informative. To let you know. In the last post, where I put a timing light on, the PFC was no longer on the car. When the PFC was on and I tested the G was a properly running, warmed up car. B was after I had checked everything in G, I did a WOT run from a stop to 3rd gear, at which point it went into gimp mode. Then I went back and tested all the sensors. This problem has me all messed up. I'm going to try to put my friends coils, plug wires, and coil harness in(if he'll let me) soon and see if there is any difference. If that makes no difference, then I don't know what to do. My mom lives in Atlanta, and if all else fails, I'm considering Mazcare.

 

did you test the knock sensor yet? how did that go?

 

Yeah, we tested the knock sensor w/ the PFC and it was pretty normal.

 

****, i was hoping that it was the knock sensor! that would seem to be a logical solution, and it is relatively easy to replace.

do you have any other rough ideas as to what it might be? i am so desperate to get the problem taken care of, and im sure you are just as much. is there anything you want me to check on my car to compare notes? i am running power fc with commander screen, so let me know.

 

I was looking back over my notes from when I was using the PFC and I saw the thing about my injector duty cycle dropping to 0%. Could this be a problem, or is that normal?

 

i think it is normal for the injector duty to drop to 0% when the revs are decelerating. i could be wrong but at least that is what mine did even before it was fucked up.

 

So who's getting the $100? How about you give me $100 if no one figures it out? If someone figures it out, I'll give you $100.

 

hey, p'cola: when youre coming to a stop, and take the car out of gear, and the idle is jumping up and down, does your brake pedal feel like it is getting mushier and firmer, mushier and firmer, mushier and firmer, with the rev pulses?

mines been doing that, and when i asked a more mechanically experienced friend (more experienced than me at least) about it, he suggested it might be a leak in one of the vacuum lines that run from the distributer to the power assisted brakes, or somewhere else directly connected within that system. do you think it might have to do with the brake booster, distributer system, or something related?

i dont know too much about that stuff, but i was hoping you or someone else here might. im hoping this might bring us one step further to getting our cars to run correctly for once!

dont give up yet p'cola!

 

I haven't noticed my brake pedal pulsing, but if your's is then I would recommend first checking the one-way check valve to the booster. That has been a trouble with a few people. A good way to check for vacuum leaks is to get some brake cleaner and spray it all around the places that are suspect. If there is a vacuum leak, your idle will change speed noticeably. Hope this helps.
As far as my car goes, I have a friend that is the mad scientist when it comes to 2nd gens. Dale Clark and I are going to go through it in a few days and check everything. He thinks it could be wiring related.