IP Timing - Chip In or Chip Out?

[Journeydog]

I've got a '95 motorhome with the chippable computer and an '03 engine with the latest Stanadyne 5521 IP. The computer has a Heath RV chip installed. Almost a mutant combo. The engine was installed by a quasi-Cummins shop that specializes in all makes of motorhomes. The guy didn't have a Tech anything, so he adjusted the new engine IP "by feel" and minimum smoke. "Been doing it this way for years." When you have a motorhome, you find out that there's not many folks that want or are equipped to handle them. I finally found a Chevy dealer to adjust the IP timing in his parking lot. At first, they didn't want me to watch them work on it, but since the tech couldn't find their manual, and I had one, he let me look over his shoulder. He insisted that since this was a '95 PCM he had to use a Tech I tool. Seems like I read here, that the T2 was the one to use. He set the timing to 3.5 and the offset to -.5 - supposedly GM spec. It took him about 20 min. of actual work (I R&R'd the doghouse cover) and about another 30 minutes of trying to find the manual and a T1 that would work. Got charged "only" $255 for this "service". He said the previous "touchy-feely" timing adjustment had been set to about 16 degrees!

Bottom line question: does it make any difference whether the IP is set with or without something other than a stock chip? i.e., Does the chip have any effect on timing? Should I be looking for another guy to check this again? Aaarrrggggghhhhh! :mad:

[ucdavis]

IIRC, Tech1 was older Chevy & ChevyOBD1 only, while Tech2 is OBD2 & backward compatible, tho only programmed for GM stuff. Technician was operating w/in his own (fractured) knowledge base, as do we all for the most part.
I suppose you had to run down the hill from BigBear to get this done so you got a good test drive; are all the SES lights/DTCs gone w/this new timing setup?

[Journeydog]

Had to make the torture run up/down the hill twice, since the main man didn't show the day I had an appointment. The only code I get now - before and after the "adjustment" is a 29 because I have a manual glow plug timer - no harm there. Before Heath's chip, I'd alternate limp-setting 78's and 62's - both due to the lack of a wastegate in the new turbo. Since the "adjustment" it starts and runs pretty well, but it ran well (hard starting, with lotsa white smoke) before the "adjustment", I'd guess the timing is in the ballpark now. Just not sure which ballpark yet.

[Craig M]

Al

I know a nice shop in San Bernardino that specializes in Chevrolet diesels. Dad and his son. Been working GM diesels since the 5.7 and 4.3 were around. They have very reasonable hourly rates and are honest. Couple of times they did not even charge me when the "fix" or diagnostic work took less than an hour. I have been using them with 6.2's only. Not sure how "up" they are on 6.5 adjustments, but for most general work I can recommend them. Email me at ccccraigcrane@hotmail.com if you want number and name.

[david]

$225 is way to much!!!!!
Book says 1 hour to set timming .
Also set it at -1.60 to -1.80 for best results.
david :eek:

[Journeydog]

Seems like the cost to work on this rig is inversely proportional to the actual work involved. I'm pretty sure that it's alot easier to adjust a pump when you're looking straight down on it, than trying to get at it with an open hood. But, then the guy has to get on his knees and he might have had a previous knee injury. The stealer that overcharged me had to pay for the guy not showing the first time I brought in didn't he? Am I a happy camper...NO...another shop off my very short and dwindling list.

And, back to my original question: does it make any difference in the timing outcome if the PCM has the OEM chip or a performance chip?

[JohnC]

Originally posted by Journeydog:
And, back to my original question: does it make any difference in the timing outcome if the PCM has the OEM chip or a performance chip? No. Base timing is handled outside the chip. Running timing adjustments are handled inside the chip.

[RLAM]

JD:
Call Bill at Heath. Or better yet, drop him an E-Mail. I have found him to be the best at Tech questions and he usually will not (cant spell wont ) try to sell you anything.
Engine has not shown up yet. Your having so much fun with yours that I can hardley wait.
Talk soon
Randy
Ps. Looks like all us MH guys should get togather and get drunk..