My apologies for the lengthy email. Here goes....

I recently had a Unichip fitted to my 2002 Magna VR-X (5 speed auto). Whilst power ATW increased 15hp (150hp ATW Dyno Dynamics), in DRIVE or REVERSE idle (eg. brakes applied) RPM bounces around from 500RPM to 700 to 800RPM approx. (assuming the tacho mark just below 1000RPM is approx. 700 to 800RPM).

This causes the vehicle to shudder and needless to say I'm not exactly thrilled with the result.

The installer is a little miffed at why this is happening and states potential issues with the factory ECU. Interestingly when the CPU was installed, and a 'map' had not been applied, they attempted to obtain a 'before' dyno run, however the car apparently would not run correctly. I'm told the method is a standard installation approach, that is install the Unichip - no map. Dyno run for 'before' results. Apply revised Unichip map, numerous Dyno runs to obtain the best result. Again, I'm told the Unichip with a 'blank map' acts like a 'PASSTHRU' device (I don't know enough about the device to know if this is correct???)

In Neutral or Park the car idles a little below the tacho mark just below 1000RPM (assuming this mark indicated 700RPM or so). However in DRIVE or REVERSE the tacho needle often drops to 500RPM and 'blips' up to approx. 700-800RPM, again causing the car to shudder (annoying).

The above mentioned is particularly evident when the engine is cold. eg. Start car, let run for 5 minutes, place in DRIVE and slowly accelerate. Result is car shudders and RPM is all over the place. The symptoms are less pronounce once the engine has warmed up. To counter this rough idle at lower engine temperatures, the installer upped the idle speed a little (screw driver job - again I don't know if this is correct). Apparently they have also tried increasing fuel mix at idle to improve idle quality - again I don't know enough to comment (much I the above I have quoted verbatim from the installer).

"Easy fixed! Let the car warm up a little" - I hear you say. Well as mentioned the symptoms arn't as bad however the vehicle still idles rough, certainly worst than before the chip was installed.

Prior to installing the Unichip my mods were (not in order), Pacemaker (Wildcat) extractors, K&N Panel Filter and Lukey Ultra Flo muffler.

I am liaising with the installer about the problem, however I thought it timely to refer the issue to a wider audience. Thanks heaps in advance for any useful advice.

I have a UNICHIP as well. Mine does not do any of the things that you say yours is doing.
I would suggest see if the will tune the car again for you on the dyno where you got the chip fitted.

Magna's can have a tendancy to run with a rough idle. Mine showed this after I fitted a Lukey muffler and K&N panel filter. Someone said that this could be expected after breathing mods. I wonder if being an auto has made this more apparent. Funny though it only showed up after the chip was fitted. I'd try another tune. I wonder if the tune has upped the power enough while idling so that the rpm increases and the torque converter starts to apply torque to the transmission which causes the rpm to dive and disengage again?

Apart from that, are you happy with the chip install and resulting drivability?

i had these problems, altho mine doesnt run the unichip, check the following, as even now, my car is tuned perfectly, i occasionally, get a bad idle, and its caused by either of the following

a) check the front (mainly, only once has it even shat the rear bank) of spark plugs. i go through at least 1 spark plug per month :oops: haha.. its random spark plug failure :x so i never know which one it is!!! bloody AC Delco plugs! they suck!

b) check your fuel filters - might of picked up some bad fuel

c) if still under warranty, get mitsu to check that all your oxygen sensors, MAP sensors and the works still work without problems. perhaps have a go at 'removing' the unitchip (i assume you can just unplug it?) and see if it idles right.

i know for me, as soon as my car rough idles, its a damn AC Delco plug. and it shits me off :x

Ben.

Mine idles a little rough, but before chipping was the same as after. It sticks at about 600rpm, when stopped drops down to 450-500 then back up to 600-650. A chip is only as good as it's tuner methinks, so by all means try and get yourself a good tune. If need be, tell him to tune it NOT for peak power but for driveability and economy, that way he may not push it to the end of the map at each tuning point, and maybe you will get a smoother tune.

Mine does the same thing, does this problem seem to effect the automatic models rather then the manuals.I wonder if it something to do with the how they set things up.They bring the throttle up so that you do not use much throttle while cruising etc.,
Mine seems to run lean (15.5) sometimes once the car has been part warmed up. stop and run again.BOOMER does yours seem to run better with the air con on???
I have read somewhere on the net that some cars run dirty at idle ie., slow air flow,left over egr stuff etc., and you need to run these cars richer at idle.

Thanks for the responses. In terms of resolving, I'm off to another Unichip installer for a second opinion.

They'll run some diag's and confirm the wiring is sound. Although it's $60 or so for their time, I figure given the cost to install the Unichip, it's worth the small outlay. Also I'm really happy with the way the vehicle drives (other than idle) and would like to see the problem corrected.

Ya never know, I might be posting a 'Unichip for sale' if the problem lingers and just put this one down to an expensive learning curve!!!

Thanks again.

Mine does the same thing, does this problem seem to effect the automatic models rather then the manuals.I wonder if it something to do with the how they set things up.They bring the throttle up so that you do not use much throttle while cruising etc.,
Mine seems to run lean (15.5) sometimes once the car has been part warmed up. stop and run again.BOOMER does yours seem to run better with the air con on???
I have read somewhere on the net that some cars run dirty at idle ie., slow air flow,left over egr stuff etc., and you need to run these cars richer at idle.

Hi eagleaus,

Apols, I didn't see your question on whether my VR-X idles smoother with the Climate Control on. In fact it does, again I can only assume the extra load causes the engine to up the RPM smoothing the idle out. Once the RPM is above 1000RPM the crappy idle is a problem no more. Be nice to have the Mitsu engineers online occassionally to bounce these queries off.

They'd probably say "leave it as a factory stocker!!!" ....but where's the fun in that. Thanks again.

Cheers, Boomer.

The Unichip agent is obliged to make sure you're happy with the tune, or he has to remove it, as far as I'm aware.
If you haven't got is sorted yet that is an option.
By the way, the unichip shouldn't have any influence on idle as it is only really tuned at wide open throttle. Also, idle is in "closed loop" engine control and it's impossible to get any sense in tuning at closed loop positions, as the engine keeps fighting the new map.

Hi,

An update on the idle problems experienced when I had a Unichip installed into my TJ 2002 Magna VR-X 5 speed auto. As per a previous post, I had another Unichip installer checked the wiring of the original Unichip installer. This checked out ok (so the installer tells me), however the problem still persisted.

However I recently had the original Unichip removed an a bridging plug installed, essentially returning the vehicle to factory. Surprise, surprise the problem goes away!!!

I emailed APS in Melbourne essentially expressing my disappointment in the installer who fitted the chip. I cannot believe that this authorised installer has not contacted APS in an attempt to resolve my problem (this was confirmed by APS). The APS engineer who spoke with me was pissed with their installer. The info about the installer modifying the vehicle before dyno did not go down well. APS are following this up.

I have no confidence in this installer at all. I certainly won't be allowing this company (man would I like to name them....can I???) to touch my car again, plus I'll be requesting a refund. Typical, nothing is too much problem for them to get your business and then they don't won't to know you. They turned around and tried to pin the poor idle on my extractors/Lukey exhaust, even though these mods have been in for over 12 months!!! Unbelievable!!!

Anyway, as mentioned no way they are touching my car again. I'm demanding a refund. VERY DISAPPOINTED!!!

Wouldnt you rather ask for free installation at another company?

I spoke to APS (Air Power Systems) about that. They're primary concern is with the process of installation. Speaking to the APS engineer each authorised UNICHIP has to follow an installation guide line.

This ensures that what APS delevope in the lab can be replicated in the field. eg. A car is to be dyno'ed prior to commencement of ANY work. In addition, if the installer has any concerns about the vehicle, they are to contact the customer immediately and not try to 'wing-it'.

So, they (APS) are addressing whether the installer has breached their guidelines and I have to pursue the installer to either...

a) resolve the issue with the chip, however as you can imagine, the installer doesn't exactly inspire me.

b) refund my money. This is my preferred option.

The whole process has left me bewilded. I can't imagine why anyone would want to conduct their business in this manner????

man dont act so surprised, this kind of thing happens all the time, not everyone, but there are plenty shops will tell you anything to get your money then tell you anything to deflect problems. You also could find any problem with your vehicle warranty will now be blamed on your mods as well.

Also notice you mention you have "Pacemaker (Wildcat) " extractors, unfortuneately you have been done just like I have with those. Wildcat are not Pacemaker. I was initially told they made by HM when In was dubious about having thise fitted instead of the pacemakeras I ordered, later when I complained they said its same product as Manta sold under diff name, get the pattern?
The pacemaker is actually tuned length 1 and 1/2 in pipes with mandrel bends, all the things you want in good extractors. The Wildcat is press bent, very uneven lengths, 1and 5/8 in piping, and bad ground-clearance loss. Im actually taking them up with the shop i got em at. (see a prev thread).

Moral is I reckon, next best thing to being able to try b4 buy is check with other people on here what their experience is with good products and providers.

Thanks man (Altera98).

I know, just jacked-off I guess. Anyway, it's no longer an issue for me. I sold my 2002 VR-X today. Traded it in on a brand new VY Series II SS.

Maybe I'll miss the smooth 5 speed tip-shifter, however a 245kw factory stocker will more than compensate.

Anyway, thanks heaps for all your advice. I'll stay tuned as this forum is excellent!

Thanks again!

Regards,

Boomer

Good Luck with the New VY SS series II.

What color?

And also what did you get on trade in for the VRX?

John

Bit of a downgrade trading the Magna for a Commodore but anyway.

What ended up happening with the Unichip ??

Did you leave it in the car or return it to APS ??

Was the chip faulty or the installer just incompetent ??

If you still have the chip and it is not faulty, want to sell it to me ??