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-   -   Jet Stage 2 and MemCAL incompatibility (https://www.gmforum.com/performance-brainstorming-tuning-96/jet-stage-2-memcal-incompatibility-220978/)

griff1455 08-18-2005 06:53 PM

Jet Stage 2 and MemCAL incompatibility
 
So I going through some stuff while troubleshooting some annoying KR. I get the bright idea to call JET and ask them some questions. It turns out that my MEMCAL code BDNJ is supposed to be the latest from GM, but the stage 2 chip that I have from JET doesn;t support it. They want me to send them both the JET chip and the MEMCAL. They are going to read the stock ship and reburn their chip to fit (apparently they don;t have the BDNJ file, just BDNH).

Now I'm gonna have to ground the old girl for a while, unless somebody has a spare MEMCAL?

willwren 08-18-2005 07:01 PM

I want more details. Especially after their diagnosis. I may need an update as well. Can you keep us VERY well informed?

griff1455 08-18-2005 07:12 PM

Be happy to, as soon as I find a spare MEMCAL to stay on the road. Any idea on a part # or price from a dealer?

willwren 08-18-2005 07:13 PM

I don't know the memcal part number, but I'd be tempted to go with a wrecker first.

I too, get KR. That's with a 2.2" pulley, only on the hottest days. My recent porting should have fixed that.

Was that your only symptom?

I may have to send my chip back to them to adjust the MAF tables for my Throttle Body porting anyway, so an update might be nice.

griff1455 08-18-2005 07:40 PM

My KR has been an ongoing battle since the install of the 2.2 pulley, it's still off right now, running the stock pulley.

Still have a tiny bit of KR. Scanned 2 instances of 3 degress tonight in 77 degree weather. Ram air feed is now in place, but still getting high IAT readings, gonna move the IAT sensor competely inside the CAI. It's just jammed into the hole on the filter and the heat sheild is mounted on the rear of the filter as well exposing the back side of the IAT. If that doesn;t lower my temps, it's FWI for me.

But there are other things. Car stumbles every now and then, usually on a long pull through second and third, like a slight miss that takes a tender foot to feel. It is ever so slight.

On the way home yesterday, she started missing pulling the mountains, but I think that might be a bad wire, changed them this afternoon.

The biggest thing is the fact that she just doesn;t feel right, lightly bogs down at times, and there is a pinging for an instant when kicking into passing gear at low speeds which keeps getting worse.

I am also suspecting a stretched timing chain allowing the valve timing to be off, but then with over 160K that's bound to happen. I just figured I would rule out the easy stuff first, it may turn out to be nothing. I can;t really be sure if any of this can be attributed to the JET programming, but they feel so strong about it, it's gonna go back. There is a definate difference when running without the chip. Seems to have no slight stumble, instance of pinging isn;t really there. Might be the "detuning" effect though.

Temps don't seem to be right either. When the 180 tstat went in, she held steady. Now it's common on a cool day for her to idle up to 200, 210, 220. Pulling hills and mountains can also be exciting.

BTW Bill, I have had my EM's ceramic coated inside and out before you reccomended porting them. They already welded them for me, just need the time to pull them back off and do a little grinding. I had asked them to powder coat the manifolds in red and the heat sheilds in black, they didn;t have red so it's all balck. Then I read the post and pics on yours. Glad mine are all black, I'd hate for us to look like twinkies. Did you port the exhaust in the heads as well?

There really isn't a good selection around here for our Bonnevilles in the boneyards. I just might have to buy a spare from the dealer.

Maybe this should be retitled "Bonnie Blues ..... A Novel". I don't type this much for work!

willwren 08-18-2005 08:31 PM

Our cars are almost identical in mods previous to my porting, and we both run the same Jet PCM. Your problems are more than likely memcal related, but that would assume we have different burns from GM. Or maybe that my car was updated at some point previous to my purchase.

The stumbling could be the PCM trying to dump boost. Have you tried the boost bypass trick? What about the BCA trick, advancing it as far as the bolts will allow? I'm really curious to see how this one goes.

I didn't port the heads at all, on either side. I simply port-matched. The welds on my EM's were restrictive enough to make the aperture smaller than the ports in my heads, so I simply removed them, and now they match much closer. I think my EM's MIGHT be slightly larger than the head ports now, but before they were smaller. I gained 16% on each EM port, and 20% on each intake port of the LIM.

Have you considered a faulty or loose knock sensor? This could be false KR, and the stumbling could be the PCM pulling timing.

griff1455 08-18-2005 08:48 PM

I never tried the boost bypass, never considered it a "permanent" mod. I have done the BCA, not much noticable there.

At times, it may be KY, at least when I had the 2.2 on and scanned it it was. But other times, like now, it is different. I scanned her this afternoon on a quick drive and there was the slight stumble, but no KR at the same time. Only KR was when I hit WOT at low speed.

I have considered a faulty KS, but the symptons don;t really indicate it, or at least from what I have read. Once I get the EM's back off, I may just go ahead and replace them.

In any event, some stumble occurs without KR.

griff1455 08-25-2005 04:08 PM

Update:

Just spoke with JET. Since I now have another MEMCAL with the same rev (BDNJ) I am sending out both the stage 2 chip and the MEMCAL tomorrow. They will read the MEMCAL and keep it on file. Once the stage 2 chip is reburned, both will be shipped back.

I also mentioned that once I see the results, there may be other folks who might have the same mismatch. They want to know. As long as you have a copy of the invoice where you purchased, they will take care of it. In fact, the guy I spoke with wants to be called directly. Now to wait ........................................

Interestingly enough, the information that I got from my local dealer indicated that my rev is for CA emissions. I don;t know if that means anything or not, they didn;t either.

willwren 08-25-2005 05:41 PM

PM me the contact you're speaking with. I no longer have my Invoice, but may be able to obtain it.

What are the total charges, if any?

griff1455 09-03-2005 02:12 PM

I spoke with JET yesterday. They reburned the chip and I were shipping it. I should have it when I am back from the road next week. We'll see what happens come next Friday! Until then, I am going to celebrate Labor day by port matching my EM's, installing new knock sensors, and inspecting my valve stem seals (that is unless my fiance commandeer's the day).


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