NB Guys running the ms in parallel....
 

Do any of you get a CEL for the crank pos. sensor? I know the thing must still work if the tachometer still works but im wondering if the ecu is able to tell that its not controlling the timing anymore?

I ran MS in parallel for about 2 weeks with no CEL. Then I removed the narrow band to install my wideband and it has been on ever since. The answer is no, the ECU will never know it's not controlling timing or fuel.

I don't get any CEL's except for the rear O2 sensor being taped up under my car :)

Check the gap on your crank sensor. If it's gapped to far out and the stock ECU is getting bad readings it might throw a code.

wouldnt the tachometer not work then?

Wouldn't you check it to see if the gap is messed up?
A CEL can be caused by a single event, it doesn't mean its a constant issue, like a single misfire. How many times have you reset the code to see it come back again?
You have an issue that I don't and neither do others, so it's hard to trouble shoot a non-common issue.

gap is fine....reset it like 5 or 6 times...starts up and within a few seconds comes back with same code (p0335 crank. pos. a circuit malfunction)

FWIW, I run .020 gap on my crank position sensor. I used a caliper to measure different business cards till I found one that was .020, then stuck it between the tip on the wheel and the sensor pushed the sensor till it hit the card, tightened the bolt, removed card. Spun the motor and no interference. Then fired it up. What gap are you running?

i had it at .016


i'll go try .020

same...

:vash:

whats the CEL code?

p0335-crank. pos. circuit malfunction

Weird. Dunno but are your plugs and wires good? I dunno if that could ever cause that code though. When did it start throwing this code? Right after your MS install?

plugs are fairly new, no more wires (thanks cops :)) and im really not certain when it started...the cel was on from the start from the maf removal. Today i put in a gm map sensor to give it a fake signal and when i went to clear the codes i saw the crank sensor one in there too.

No issues here as well, only the occasional rich/lean code.

Jim

you need to keep the MAF plugged in. that might be the reason for the codes. plus, your alternator wouldnt charge your battery unless you swapped to an older model alternator.

Without the MAF in place, the stock ECU can't idle well (the idle oscillates too much) if you still have the idle valve under stock ECU control.

If you mean the MAF has to be plugged in for the alternator to work that is not correct based on my experience. My MAF is completely out of the car and my alternator works fine.

Do you mean just plugged in, or plugged in and actually in the intake plumbing? I have had trouble getting the idle stable at anything above 13:1 and my MAF is not plugged in (removed from the vehicle). Reinstalling it might be worth a try.

I believe Chad (cjernigan) has his in the car, plugged in, but not installed in the intake flow. As far as I knew that was just to avoid a CEL, not idle related.

Actually i've had my MAF installed in the intake path since I bought the car. I also had it plugged in to avoid CELs. I don't know how it would affect the idle.
I do know the fequency of the NB valve if you want to do some idle control, it sounds like we might need to if we want to successfully remove the MAF. I plan to leave it out with the new turbo setup so i guess i'll be using that idle mod after all :)

hmm, dont know then

I *think* that the sensor which is critical for alternator operation is one of the two temp sensors- IAT if my memory serves me right.

^^^

+1, thats what ive heard too.

There was no problem with the maf unhooked other than the code for "maf input low". The stock ecu still kept the idle perfect and the alternator must be still working because i've been driving the thing for a few weeks now and it fires right up every time.

FWIW my stock IAT is still connected but just sitting under the hood, not in the intake flow.

I just picked up a ODBII reader and the only CEL code I have if I read it correctly is a code for the MAF input low error mentioned by mikeflys. So when I go in for an inspection (several months away) I'll just plug in the MAF and clear the code. Hopefully that will do the trick.

So, to answer the OP, nope I have not had a problem with the crank position sensor error. MS-1 parallel install with a CAS.

If that is indeed the cause of my idling instability I might be up for some idle control. That being said, it is not too bad right now. I have it at about 13:1 and have the timing retarded in the idle region to about 11. Set up like this, it goes up and down with the A/C from ~900 rpm (a/c disengaged) to ~1200 rpm (a/c engaged). When the a/c is engaged it will run at 14:1 no problem. It also does this thing where if I come to a complete stop after de-accelerating, like at a stop light, it will idle at 1200+ for 5-10 seconds, then drop to ~900 rpm.

When I sit at idle for a long time, like 3-4 minutes it will get unstable again with the a/c disengaged. I think it is probably due to heat soak though I am uncertain of the exact cause and effect.

It is not a big deal so I can live with it for now since it is still completely drivable. I would not want to put the MAF back in the intake flow just to improve the idle. If just plugging the MAF back in helps then I'll do it.

It will be interesting to see if your idle changes with a no MAF setup Chad. I had assumed my idle tuning problems were only due to the big injectors.

I'm removing the MAF with the throttle bodies, so I'm doing the idle mod as well. As soon as the car is warmed up (ie idle in closed loop vs open loop warm-up), the idle starts to oscillate between 700-1200rpm without the MAF in there. I also get occasional oscillation when I let the MS control the ignition and the stock ECU controlling the idle valve, especially with the A/C on. As soon as I return the ignition control to the stock ECU, everything is golden. It doesn't matter if I use a flat ign map around the idle zones or I use a "valley" map, it's all the same.

Btw the idle valve frequency on my 2002 is 500Hz, what's it like on your '99?

Jim