Major Gremlins in tune/PCM. Please help.

[carneb]

I have been tuning for about a week using the Roadrunner PCM and have been getting the hang of it, with the tune improving each day. I have had a problem that when the cooling fan kicks in while idling, the engine dies. I have tried heaps of things including B4301, Desired air, richening up idle, but it still stalls. I turn the a/c on and there is no problem.

Yesterday while driving home the car started surging badly and the check engine light came on. I pulled over and the engine died. I restarted and all seemed OK. I checked the DTC's and found Cam position sensor circut high, cam position sensor circuit low, and Theft deterrent learn mode. I hoped it was just a gremlin.

Today while driving home as I pulled away from a traffic light the car started surging again, but no check engine light. It was so bad I had to stop. The car would idle OK but as soon as any load was applied it would buck like crazy. I turned it off and tried again but same thing. I flashed back in my last tune and it bucked a bit for a second but then was OK and I got going and got home.

I checked the logs and the injectors where being shut off, like a rev limiter! Attached is a screen grab of the log.

http://users.bigpond.net.au/bcar4179/gremlin.png

Also attached is a pic of the log where the fan starts and the car stalls. When I restart some strange things happen.

http://users.bigpond.net.au/bcar4179/fan.png


My car is a VY Commodore with 222/224 112lsa cam. The tune is based on a 2004 VY GTS with custom os1.

Can someone tell me what is going on?

[Delco]

Are you using a laptop with a 12v invertor or the battery ?

Disconnect the pcm from the car for 5-10 mins , reconnect and then do a full flash then disconnect the RR USB cable and see if the issue is still there.

I have seen this sort of issue before when the data gets corrupted when using a laptop with a invertor supply.

[carneb]

The laptop was running off its internal battery but it was connected to the Roadrunner (physically and software) at the time.

Before doing the reflash after the problem occured I had to reboot the laptop to get it to communicate with either the Roadrunner or V1.2 cable. BUT I had turned off the ignition without disconnecting either in software.

I'll try your suggestion thanks Delco.

[ringram]

You might want to try the stock pcm again to eliminate the RR from the source of possible issues too.
See if you get any dtc's with that etc.
Might be dodgy ram in the RR etc. PM Craig at Moates he might have some suggestions once you have eliminated other possible sources.

[ringram]

I just noticed your air is 0.21g/cyl mine is 0.14 at idle. When I first got my cam it stalled with too much air. Have you done your RAF tune? Did you change your effective area table as Tordne sugguested, with say the R8 285KW one? If you want I can send you my current 220/224-114 cam tune. PM me your email addy if you do.

Dont worry you will get there, there are a lot of things that can mess with stuff.
If thats the comp cams cam with around 27x adv duration then it should idle with better map than that too. I get 40kpa with 282 duration (but slightly less duration than you at 0.050) Im thinking its getting a little too much air now.

[SSpdDmon]

There's some major swing in spark in that first log. That might be another source for where the surging is coming from.

[carneb]

I just noticed your air is 0.21g/cyl mine is 0.14 at idle. When I first got my cam it stalled with too much air. Have you done your RAF tune? Did you change your effective area table as Tordne sugguested, with say the R8 285KW one? If you want I can send you my current 220/224-114 cam tune. PM me your email addy if you do.

Dont worry you will get there, there are a lot of things that can mess with stuff.
If thats the comp cams cam with around 27x adv duration then it should idle with better map than that too. I get 40kpa with 282 duration (but slightly less duration than you at 0.050) Im thinking its getting a little too much air now.

The second log I posted is when I had increased some cells in the VE table around idle as they looked lower than surrounding cells. As you can see that gave me a 12.8:1 AFR at idle, maybe thats why the DYNCYLAIR is high. Looking at a previous log it is usually 16g/cyl and 47kPa MAP at idle. I've done my RAF tune and the car idles quite nicely, except when the fan starts :frown:


There's some major swing in spark in that first log. That might be another source for where the surging is coming from.

I think the big issue in the first log is the injectors. (green trace bottom chart). They are flowing then off, flowing then off etc. Very strange :frown:

I've put the old PCM and program back in the car for now to make sure that runs OK. On the weekend I'll follow Delco's suggestion with the Roadrunner and have another go.

[Doc]

There's some major swing in spark in that first log. That might be another source for where the surging is coming from.

As a fellow Moates owner, I'll second this idea.

[carneb]

As a fellow Moates owner, I'll second this idea.

Do you mean you have had problems with spark with your Roadrunner, or that it's a problem with the spark and nothing to do with the Roadrunner?

Will the fluctuating spark cause the fuel to be turned on and off?

[Doc]

Unfortuneatly I have not been able to use my RR on my 98Z, yet!-Soon:) What I meant was with my H/C/I combo I had surging issues that ended up being cured with spark table adjustments. Everybody elses' cars have had the Moates Controller put to use on it with great results-nice piece of equipment.

[Black02SS]

Sent you a PM>

[carneb]

I emailed Craig Moates about my problem and he asked me to check if the problem only occured while my laptop was connected to the RR. I put the RR back in the car today to test it. At first the car wouldn't start and the check engine light came on. I turned it off and tried again and it started. I let it warm up and the fan came on and the car didn't stall. I went for a drive with no problems. This was all with the laptop connected!

So it seems that I can't confirm that having the laptop connected while driving was the culprit or not. In future I won't leave it connected while driving, just as a precaution. It doesn't need to be connected unless you are making changes anyway.

I have decided to start again with a fresh base tune just in case the other one had been corrupted. I copied across data from all the tables I had played with in the other tune. I loaded this into the RR and went for a test drive and had no problems whatsoever. When the fan cut in the revs didn't even drop.

I just hope the gremlins don't re-appear. Thanks to those who gave me their help :cheers:

[Doc]

I drive around with my laptop connected all the time;)

[Black02SS]

I drive around with my laptop connected all the time;)Some have had this issue though. ;) And when is the last time you had a chance to drive it? :sad:

[Tordne]

I can't drive my car without the laptop, I just don't trust what its doing if I can't see it :D

Would be nice to have a rig in the car to rest the laptop on. I just sit mine on the passenger seat.

[Doc]

Chad, ya got me! Block should be back from the machine shop on monday. Forged bottom end to go in thereafter...Ford 9" w/3.73 ready to go, UMI tubular kmember + suspension should be here next week too. Seriously, I don't think the laptop spun #6 rod bearing...I am pretty sure it was my never ending need to drive the hell out of the car. TT w/upgraded OS, yes for the 98, soon. If I can just stay in this country long enough to keep up with things.
:cheers:

[carneb]

I've been driving around with the laptop connected to the Flashscan cable AND connected directly to the RR. I'll still have the Flashscan cable connected all the time just not the RR cable :)

That setup you have for the laptop looks excellent Doc. I would love to have something like that. Have you had any dramas with the Police though? I have mine on the passenger seat at the moment but I'm worried that if I have to stop in a hurry then its goodbye laptop!

[Black02SS]

My laptop setup is just like Docs and I have never had a problem. I do drive my everyday and it is there most of the time (even if I'm not logging). I have never had a problem, but my windows are 5% anyway so no one can see in. :lol:

[ringram]

Hey carneb, you want to get that sorted, thats the point of the RR. Being able to drive and tune and log. Let Paul know as well as he wrote the tuning/logging side of the solution.

[Doc]

No dramas with the police but, I think it has made a few other motorist do a double take and slow down. Bout that time I'm opening up the QTP:muahaha:

[carneb]

I've been doing some idle tuning with the RR over the past couple of days and have found that as soon as the car warms up and the fan cuts in the car stalls. If I disconnect the laptop and restart the car, when the cooling fan cuts in the car keeps running with no problem. This means I can only use the RR for real time tuning when the car is cold :frown:

[Delco]

I've been doing some idle tuning with the RR over the past couple of days and have found that as soon as the car warms up and the fan cuts in the car stalls. If I disconnect the laptop and restart the car, when the cooling fan cuts in the car keeps running with no problem. This means I can only use the RR for real time tuning when the car is cold :frown:

Do you have your laptop powered from the car when this happens or from mains power or battery , a couple of issues can arrise , one is the power required to drive the laptop invertor causes a higher load on the alternator which will tip the idle over when even more load is applied through the fans , sounds like your idle is only JUST stable and cant handle the extra loads.

[carneb]

I always run my laptop from its own battery when in the car. It seems if the laptop is connected to the RR the car stalls. If the laptop is not connected the fan starts with no problem, not even a noticable dip in revs. :nixweiss:

[Delco]

Thats strange , I have had similar issues but only when powered off the car 12v supply.

Maybe shoot a email off to craig