Danno

Hmmm, when you drive the car hard, you increase the heat generated in the DME because of the larger amount of time the injectors are open (driver-transistor flows more current).

This heat appears to cause some failures in our chips. Got a note from an EE that perhaps this is due to incomplete erasing of the chips before they are programmed. I'm going to try zapping them a little longer and swapping to a different brand of chips...

You guys should be seeing a new set of chips before this weekend. Along with all the others who've been waiting for their new chip kits as well.

dlr944

Danno:

Any change you can use a flash rom instead of a Eprom?

guardsred951S

Dunno if this applies but if a chip doesn't get it's fair share of voltage or overheats, then it will start messing up its calculations. This goes for any semiconductor although it's more common in computers where people try to overclock their CPU's without properly cooling them. In the DME/KLR's case, would it be possible that the chips aren't getting enough juice and are messing up? There could be just enough difference between the factory chips and the Guru ones that the factory ones aren't shutting down and the Guru ones are. Also, burning a chip requires that you raise the voltage on certain pains to something like 13V depending on the chip and if you can't get there, it won't burn properly. Are the chips UV erasable?(maybe a stupid question) - sunlight can wreak havoc on whatever you burnt on them.

<img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />

morefun

Interesting, I've had my v8 chips in the car now for about 1,500 miles and havn't had any issues. It just goes like stink and sucks gas like Danno works for OPEC.

Cheers,

Mark Williams

'87 951 w/LSD 51,000 miles w/Guru chip kit including 3 bar FPR, Reliaboost, wastegate shims, Bursch test pipe and Strato diverter valve - needs suspension work now

gatorbait

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by RJP 951:
<strong>Danno,
I installed the chip kit (DME v8c) and new FPR this morning, and something is terribly wrong. I took the car out for a test drive and it seemed OK at first, but once the engine warmed up it was really running poorly.
Symptoms:

1) Around 3000 RPM the engine starts stumbling, and at 3500 - 3800 it bogs down as if there is no power at all. This occurs even under light acceleration. Under heavier throttle, it will intermittently "catch" and surge ahead for a moment and then bog down again.

2) The idle seems fairly steady, but there are blips that sound like it's missing a beat every now and then.

3) The engine is backfiring after letting off the gas. This is something I've never heard it do before. IRon</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I, too, had an almost identical experience last week when my Guru v8c chips were installed. The only difference is that the motor died after a few minutes, leaving me stranded and in need of a tow. After being towed to my mechanic's shop, the car re-started thirty minutes later, only to repeat the same symptoms before the motor ultimately died. Had to re-install my Autothority chips to make the car drivable.

Two weeks prior to this, my first set of Guru chips were dead-on-arrival (from what I understand, my chips were part of a bad batch of Guru chips that went out last month). As with last week's experience, I had to re-install my Autothority chips to get the car to run. The other components of the Guru chip upgrade kit that I bought (Reliaboost 1 and the the Bosch 3-bar FPR) went in easily, were installed correctly, and are working well.

In fairness to Danno and Travis at Guru, I'm not 100% sure if the FQS switch on the DME was checked for position prior to installation, although I'm reasonably confident that it's set at "0", (which is the appropriate setting for my car)--even more so now that I've read RJP 951's posts on this topic. This makes me wonder if Guru has worked out whatever hardware/software problems beset them in February.

Last Friday, Danno has promised me a third set of chips, which I hope will arrive soon. I know that it certainly wasn't Gurus' intention to generate this much heartburn for me, but I'm getting a bit anxious to get this over with, since I paid for the chip upgrade kit the third week in January, and I still don't have their chips in my car.

BTW, if it turns out that the problem for the second set of failed chips was on my end, I'll be happy to post again and say so. If that's not the case, and my third set of Guru chips fail, I'll be in the market for an Autothority Mass Flow Sensor package (used, if I can find one).

My preference though, is to go with a Guru chips. Providing I can get their chips to function in my car, and I'm pleased with their performance, my next purchase will be a MAP Stage 1 kit.

gatorbait

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by michaeldean:
<strong>I think I might have a similar problem. My 951 has the Guru chips, 3.0 bar FPR, wastegate shims and the reliaboost valve.

With stock DME & KLR chips, it runs & revs smoothly. Historically, I have had problems with the Guru chips – mostly involving misfiring/clattering at 4000 rpms. Cheers,
Michael1986 951</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">I missed Michael's comments the first time I read the posts in this thread, and this comment worries me.

Are there historical reliability problems with Guru chips, or have all of these problems come about in recent weeks?

For contrast, I drove three E36 Bimmers over the last eleven years (before buying my 951 in December), each with a chip from a different tuner, and never had (nor heard of) chip failures. What gives?

RJP 951

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Danno:
<strong>... I'm going to try zapping them a little longer and swapping to a different brand of chips...

You guys should be seeing a new set of chips before this weekend...</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Danno,

Will the set you're sending out now be using the new brand of chips and erase/burn method?

I know "stuff happens" sometimes and that you want to get this sorted out just as much as I/we do.

Thanks
Ron

silicondigital

I hope the ones im about to get dont die like all of yours... Dont want to become a contributer to the thread.

David Salama

I too am waiting for my GURU chips. With all these posts, I'm now a little nervous about them. Everything we've previously seen with Dannos involvement has been outstanding and I am confident that Danno will trouble shoot these chips and make the appropriate fixes.

Danno,

All I ask is that you keep us in the loop with as much information as possible about what you figure out, and tell us when our chips are actually sent with a tracking numbers. If we know whats going on we won't be so anxious waiting for the UPS truck every day. Thanks Danno.

Bri Bro

The fact that some chips are working great and others are having problem points to an IC, not a code problem. I am sure Danno will get this supplier/process issue resolved in short order.

At least Danno is accessible, has anyone had a problem and the companies technical support disappears...that sucks!

Matt Sheppard

Hey, mine work great. A little goofy when cold which I think is idle-air stabilizer, but man it runs well when warm.

Danno

"Will the set you're sending out now be using the new brand of chips and erase/burn method?"

If someone can point me to a manufacturer/supplier that's selling new virgin chips, please let me know!!! I can't find anything but pulls and reased ones. Well, I drove up to Santa Maria (1-hour north) to an electronics shop to buy out their entire supply of chips. They were nicely individually carded and all, but were pulls too! Anyway, I sent out 5 sets yesterday, 5 sets today and will send out another 5 tomorrow. Everyone who's waiting for updates, replacements or new kits will be getting them before this weekend. Sorry for the hassles. <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />

michaeldean

</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by gatorbait:
<strong>I missed Michael's comments the first time I read the posts in this thread, and this comment worries me.

Are there historical reliability problems with Guru chips, or have all of these problems come about in recent weeks?
</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Hi:
I was not quite clear - the only history I was describing was the operation of the Guru chips in my particular car - I have definitely not seen many questions about the reliability/quality of the Guru chips until now - so I still have every faith that Danno will sort out this problem.

Until I heard of other people's problems, I thought there must have been something wrong with my car - perhaps something which is exacerbated by the use of the Guru chips… a problem that the stock chips did not elicit.

By the way, the first set I tried was in November.

I look forward to trying out the new chips Danno - and appreciate the excellent product support you provide! The tabs on my DME and KLR boxes are suffering metal fatigue so I hope the next set is the charm

Cheers,

Michael

Bri Bro

Michael, put new socket on top of you current socket before something breaks. You will then remove and install the EPROM into the new second socket. It will not effect the performance of the IC and if you do break a pin in the second socket, you just pop in a new on. I have done this many times in the past with good results.

michaeldean

That's a good tip.
Its not so dire though - I'm speaking of the tabs for the metal case on the DME/KLR boxes that needs to be bent up each time the box is opened.

Michael