PCM Tuning Service

turtleman wrote:

AA wrote:

I think if you pull the PCM fuse the fuel trims (bad fuel table) will reset.

Ok but is there anything that can positively tell you in real time if it's running that table? I am not nearly familiar enough with what the timing advance numbers look like during any engine condition to tell from that.

If you were running an aeroforce gauge watching your KR and timing, and were familiar enough with watching the good timing table, you would know after seeing a long period of KR followed by a change in the amount of timing called for. After a period of time on the 'bad' table it should continue to try to revert to the 'good' table again. There's no other indicator I know of.

You guys have me confused now...

Are you talking about fuel tables or spark tables?
And isn't the fuel trim constantly adjusted anyway?

It's a "Bad Fuel" spark table. Whatever the mechanism is to switch over to bad fuel spark table (probably a KR threshold), I'm not positive, but I'd think it should be reset when you reset the PCM.

AA wrote:

It's a "Bad Fuel" spark table. Whatever the mechanism is to switch over to bad fuel spark table (probably a KR threshold), I'm not positive, but I'd think it should be reset when you reset the PCM.

You mean the amount of timing and time-duration that the KR retards?

Yes, I think that's what the PCM uses to switch to the bad fuel table. Other than KR, I don't know how it could know what type of gas you used. I think it's a combination of level vs. frequency, and maybe duration, not sure. I've never seen the bad fuel table activate, that I'm aware of.

I know one thing from scanning my car - my Rivi computer pulls a lot less advance, and restores it MUCH quicker, than our old Turbo Regal did...

I'm still looking around for a spare 97 PCM, just been so busy lately.

I still don't understand why you would want a spare PCM. You pay a pretty penny for it, you have to tear out the dash to install it, and you always have an extra PCM on the shelf not being used. Doing that is like buying and installing a separate engine to change your oil. Why not just open the drain and change the oil?

The simplest way is to find someone with a tuner, plug in under the dash, and wait 1-2 mins until the program flash is complete. If you want your old PCM back, you just plug in and wait another 1-2 mins to install your original program.

I used to think I physically needed to install a separate PCM, until I learned how easy it was to plug in to OBDII and flash from a laptop. Why not drive to Deekster's garage? You guys could even meet halfway somewhere, tune it in a parking lot.

AA wrote:

I still don't understand why you would want a spare PCM.

I assumed that he was referring to the need for a spare in order to send his own out to be tuned...

( If only the price wasn't so high for tuning software, even when you provide your own hardware [laptop]... )

AA wrote:

I still don't understand why you would want a spare PCM. You pay a pretty penny for it, you have to tear out the dash to install it, and you always have an extra PCM on the shelf not being used. Doing that is like buying and installing a separate engine to change your oil. Why not just open the drain and change the oil?

The simplest way is to find someone with a tuner, plug in under the dash, and wait 1-2 mins until the program flash is complete. If you want your old PCM back, you just plug in and wait another 1-2 mins to install your original program.

I used to think I physically needed to install a separate PCM, until I learned how easy it was to plug in to OBDII and flash from a laptop. Why not drive to Deekster's garage? You guys could even meet halfway somewhere, tune it in a parking lot.

1) I wasn't aware that it was that difficult to install the PCM. I thought it was in the engine bay for some reason.

2) I always like to have spare parts just in case.

3) If the tune doesn't go right I'm stuck at Derek's or half way there.

4) I didn't want to pressure Derek to get the tune done right. If he still offers the tune (which I really hope he does!), it will give him time to tweak and such, upload it to the PCM and send back without any pressure.

I'm sure its extremely easy like you describe but I'm still new at this computer tune stuff but whatever way is easiest, I'm down for that. Of course its mostly up to Derek because he is the one that would be doing the tune. I just want to make it easy for both parties.

Eldo wrote:

I assumed that he was referring to the need for a spare in order to send his own out to be tuned...

( If only the price wasn't so high for tuning software, even when you provide your own hardware [laptop]... )

Yup, that is pretty much the reason!

Yup, thought so.

Don't worry about that first part... If I recall correctly, all you have to do is remove the sound-deadener (kick) panel and the glove box, and the PCM practically falls out by pressing a couple of plastic tabs.

AA wrote:

PCM. You pay a pretty penny for it,

Myself and local members in MN have paid 15-25 bucks for PCMs in local bone yards.. not too bad In my opinion

I guess I see your points, but in this situation, how far are you from Derek's location? 50 miles? 80 miles? I could see buying an extra PCM if you lived far enough away to make it worth the cost. It may not be that hard to replace the PCM, but it just seems unnecessary when you have the ability to flash it through the OBDII port.

The idea to have a spare part just in case makes sense in the case of parts that break, but PCMs don't normally fail. You have a better chance of damaging the wiring harness during installation. But it shouldn't be a worry anyway if you're paying Derek for the PCM tuning service. There should be a certain assurance when you do business with a service, or else you should get your money (and a fresh PCM) from the vendor on the spot. In other words, you shouldn't feel like you're pressuring Derek to get it right - it's his job to get it right, and to look out for you in case something goes wrong.

You can give him all the time he needs to write the program, but that doesn't require seeing your car, or your PCM. He can do all of that on his own computer. The only reason he needs to make contact with your vehicle is 5 mins to hook up and reprogram it. If something goes wrong, it should be Derek's responsibility to have a spare PCM that he can swap in. If you want Derek to do a flash, then scan your car and do a custom follow-up tune, that's an additional service that might require extra time in the car. I don't see how an extra PCM would make that service any easier.

As for the idea you can buy a PCM for $20, maybe if it was in a flood or a fire, but otherwise I call BS. You can't know what you're getting there - no guarantee it will work. If you check any online parts store, a PCM is between $170-200 for a blank PCM, and over $300 for a programmed unit. Same at AutoZone or Napa. If you check Car-Part.com, a database of junkyard inventories across the country, the price range I found is between $200-320 for 'boneyard' parts. Imo, using a PCM bought for $20 is a FAR bigger risk than getting a PCM tuning service from someone like deekster, who is a long-time member we can trust to do the job right.

I am ready to get rolling with this. I have a spare PCM, it's from a 2000 GTP but I understand they are all the same. I have an offboard, and a '98 Riv to test with.

I don't think it's very hard to get the PCM out - you remove the glove box, then a few screws and clips and it's out.

Vinny, there's no way you would be stuck here

The problem with doing long distance tuning is that the recipient won't have the proper CASE learn, and will need a tuner or dealer to do that. So the option would be to send out a tune, he drives it without a case learn while sending his PCM to me, which I reflash with the same tune, then he gets his PCM back which won't need a CASE learn. Also, sometimes the 'other' PCM could require a security learn procedure. Therefore, it's always better to have your PCM tuned directly. Plus, if we make a day of it, I can dial in your tune for you, rather than take some guesses, then rely on you for some scan feedback, then take some more guesses... it will be much better when I just hook up and we go.

I don't have a DHP powertuner anymore, I've gone HPTuners, and only unlocked 1998 as of now. I will unlock others as needed when the time comes... but for now I'm only '98 capable.

Well lets say we all see eye to eye on all opinions. Just going to go with the most logical/cost effective way to go. That way seems to be me going to Derek's and I have zero problem with doing that. I love road trips!

Good news Derek! Like I said above I have no problem coming to you and having a tune day. Based on what you said above that seems to be the best option for both parties for multiple reasons. I just have to get going with my mods now so I can take advantage of the tune.

What I have so far:

A104's - Installed
180 Stat - Not installed yet
3.4 pulley - Not installed yet (need a puller)
Gatorback serpentine belt - Not installed yet
Hopefully piecing together a FWI next week and flushing the tranny.

Ideally I'd like to get all the mods plus a few more on before the tune to maximize it along with taking advantage of changing shift points to avoid installing a shift kit since that seems to be the census.

How much does it cost to unlock a year?

Just schedule it with Derek and pay him to do the work on the car as well.
That's if you don't have the time and he does.
I can vouch for the quality of his work.

Are you putting on any other real airflow mods besides the 3.4? If not, I strongly recommend starting with a larger pulley. I was never able to get my car running KR-free on a 3.4 until I put in 1.9 rockers.

Rickw wrote:

Just schedule it with Derek and pay him to do the work on the car as well.
That's if you don't have the time and he does.
I can vouch for the quality of his work.

Eh, no offense to Derek or anyone but I do all my own work and I rarely trust anyone working on my car. The one time I let someone touch my car and something gets messed up. Never again unless I don't have the necessary tools or knowledge which isn't too often, case in point with the tuning. Plus I save a butt load of money.

deekster_caddy wrote:

Are you putting on any other real airflow mods besides the 3.4? If not, I strongly recommend starting with a larger pulley. I was never able to get my car running KR-free on a 3.4 until I put in 1.9 rockers.

Yes, I have been reading up on the 1.9 rocker mod vs cam and doing some research on that. 99% sure I'll be doing the rockers. I'm waiting to hear how Abbadon (scott) likes his headers that he just ordered and I'll probably go with a set of those along with some sort of modified exhaust.

So I have a few things planned in addition to what I listed in my previous post. I know that looked kinda sad but I'm not going to be one of those guys who just throws a pulley on the car with no supporting mods.

Right now I'm still kind of in maintenance mode getting the basics finished on a car that has been severely neglected. ( brakes, shocks, struts, springs, transmission fluid/filter, fuel filter, s/c oil etc, etc)

Does anybody know of somebody in MN that is able to tune a '96 Riv?

54_nailhead wrote:

Does anybody know of somebody in MN that is able to tune a '96 Riv?

A certain Travis aka 98Riviera98 runs a baller E85 tune, maybe he can be of assistance

L67 wrote:

54_nailhead wrote:

Does anybody know of somebody in MN that is able to tune a '96 Riv?

A certain Travis aka 98Riviera98 runs a baller E85 tune, maybe he can be of assistance

ohhhhh hi there!!! ill hit up matt (mr riviera) and see what i need for a 96 as far as i know mines unlocked for 97-03 however i have access to 04+ now with my dhp...

54_nailhead wrote:

Does anybody know of somebody in MN that is able to tune a '96 Riv?

werd. i didnt know there was another ullied riv in minnesota lol... what city are you from?

Travis, I'm living in Waconia right now - southwest burbs not to far from Mound.

54_nailhead wrote:

Travis, I'm living in Waconia right now - southwest burbs not to far from Mound.

ill send some PMs later... in on my phone.. do you have dhp 1.5 yet? or are you looking for a custom tune?