lnbrown5981

Hey there I have been having difficulty getting the engine idling on the pnp megasquirt. I can keep it running with my foot on the gas but as soon as I let off the car dies. This happens when hot and cold. I tried messing with the afterstart enrichment and warmup settings which helped alittle, but still no luck. Also I calibrated the TPS using megatune, and I noticed that the Throttle reads 100 when the pedal is only half way down. Could this be because of the S4 TPS being narrowband or could it be somthing else.

If it is the TPS I have an S5 throttle body and TPS, could I possibly wire in the s5 Tps so that I can have a fuller range? I am going to see if I can post my current msq maybe that will help.

muythaibxr

It might not be your msq causing the problem...

That msq runs our NA project cars no problem, and they idle fine right around 800-1000.

I would suspect that either your BAC valve is broken, or your idle screw needs adjusting.

lnbrown5981

i played with the idle screw to no avail. I do not have a BAC valve (it was originally blocked off), and I have a modified throttle body, which do to the lack of the cold start could be why it wont idle when cold, but it still will not idle when warm either. Right now I am using the TII msq that you emailed to me. I had no luck with the NA msq either. Could installing a BAC valve possibly solve the problem?

muythaibxr

well, usually if it won't idle low, there's somthing else causing the problem.

The main things that could cause it are ignition timing that's not set right, not enough air, or too little or too much fuel.

Do you have a wideband O2 controller installed?

Ken

lnbrown5981

I do have a wideband connected and when I hold it running the afr sit at around 10.89. It is running very rich.

muythaibxr

sounds like you need to adjust it leaner then... idle should be between 12:1 and 13:1 in my experience...

lnbrown5981

Would it be better to adjust the ve table or the afterstart enrichment and /or warm up tables?

muythaibxr

usually I start by adjusting the req_fuel value (which is probably too high if you didn't change any settings on it when you got it)... Just changing that should be enough.

You can send a message to tofuball to get our T2 settings if you haven't already.

Ken

lnbrown5981

yup thats what I'm using now. When I got the TII map the req fuel was at 8.7, I'll go give that a try now. Be back soon with the results.

muythaibxr

I think his T2 has an exhaust leak, that might lead to needing a richer table. (It certainly did on my NA).

lnbrown5981

OK just came back from trying again. Turns out the ECu ground wire coming out of the harness (the one connected to pin 24p on the stock ECU) broke right where it meets the plug to the ECU, so I have no way of splicing and soldering it back on.

Are the Ecu plug pins (on the harness, not the board) all interconnected or are they individually removable. If I can unplug that ground pin from the harness plug I can splice in the other half of the broken wire. Any Ideas on this one?

muythaibxr

I think that the ground that's on the middle connector connects to all the sensors, and the rest of the grounds eventually all connect to the same ring terminal under the intake manifold on the engine. If it's one of those ground wires that broke, you should be able to just splice another wire in where that broke as a temporary solution.

However, if you have wires in your harness that are that fragile, you may want to consider just replacing the whole thing...

lnbrown5981

It was the ground on the middle harness that broke. Sad thing is, this was a BRAND NEW wiring harness

Here's a picture of the harness sorry but the pic is a little blurry

muythaibxr

That's unfortunate.... and it broke very close to the plug too...

To fix that, I would suggest the following:
1) push the pin out of the plug
2) strip some insulation from both ends (not much, as you don't have much to work with)
3) solder the ends together
4) put some heat-shrink tubing over the exposed wire, and shrink it on
5) shove the pin back in the plug.

How did you manage to break a wire on a brand-new harness? Did you buy it from a dealership? If you did you should be able to get them to replace it as it sounds like it was likely a manufacturing defect.

Ken

lnbrown5981

No I bought it from Malloy Mazda a little over a year ago. I am guessing I must have bent it the wrong way or something must have been pressing against it, because none of the other wires are brittle. Going out there now to see if I can fix it...

lnbrown5981

i repaired the wire, and it looks like my problem is possibly ignition related. I hooked up a timing light to both igniton coils while cranking and I am getting no light. I tried the light on my buddy's car and the light lit up perfect. Tomorrow I will go out and run a test on the CAS and see what happens. I give up for today... MS-5, Me-0

lnbrown5981

Ok. The coils and the CAS both checked out good. still getting no spark. I am going to try charging the battery up as I noticed that it was a little below 12V. I'll see if that helps....

muythaibxr

You didn't reflash or anything did you? Do you get spark with the stock ECU? Do you have the CAS stabbed as stock?

Also, the wiring for ignition "stuff" is on the largest plug, which runs separately from the other two... (emissions harness I believe), did you verify that part of the harness is ok?

lnbrown5981

Up until the other day it ran perfectly on the stock ECU. On the MS I do have the CAS stabbed like stock. Now it wont even get spark on the stock ECU. The larger plug appears to be intact, and I did repair the ground on the middle plug. I am kind of stumped right now.

muythaibxr

Yeah, I would suggest figuring out what's causing you not to get spark on the stock ECU before switching the MS back in. That'll help rule out one variable.

Do you get spark on trailing while cranking with the stock ECU?

Ken

lnbrown5981

Got it started on stock ecu. Chalk it up to a bad battery. Going to re-stab the CAS tomorrow. And go for round three on the MS. wish me luck....

lnbrown5981

Ok, I give up!!! The car idles and drives perfectly on the stock ECU, but will not even start or idle on the MS. All I get is loud backfires and a flooded motor....I tried changing the req fuel, the ve, afterstart enrichment, nothing is working... Anybody know a good MS tuner in Georgia?

muythaibxr

It does all that on the map that tofuball sent you?

Any datalogs of the attempts?

Ken

lnbrown5981

sorry, no datalogs...Taking it to a tuner in the near future I will let you know how that goes.