PDA

View Full Version : bought someone elses project and am trying to get it right.



redfury
February 14th, 2011, 05:37 AM
Okay, so I made the mistake of buying something that wasn't 100%. What I've got is a 98 Astro with a 99 Savanna Vortec 5.7 with a 97 c/k PCM...wut? In my travels, I've discovered that the PCM was tuned. However, what I am discovering is that the 97 and 98 had differences...many of them. It's obvious that the PCM was wired into the van instead of replacing the harness, so I'm pretty positive that I have a 98 harness.

Which leads to two issues. One, I have no gas gauge. Two, I would like to just be done with the whole mess and rewire it for the 411 PCM.

My question lies within this...the Van has true dual exhaust, no cats, no secondary O2 sensors. I've got a persistent P1406, one bank O2 sensor code and a code for the TPS voltage low. TPS was replaced, EGR was replaced. No difference, no new codes. The engine will run 1500rpm when it's started on some days, some days it's 1000rpm. Some times it will run at 1500rpm at idle after it's warmed up, sometimes ( more often than not now ) it will idle around 700rpm. If it were an intake leak, it would happen more consistently than it does, and if the EGR was blocked with carbon, you would think that I would see it in the EGR itself, which it is clean. The passage going into the intake is clean ( no black deposits )

Also, the security light is on on the dash. It goes out sometimes when I start the van, and then comes back on. So far it hasn't affected anything as far as I can tell...just annoying.

At any rate, if I do change the PCM to the 411, I assume I'm going to throw all sorts of codes. I don't have access to any kind of reprogramming software, and have a hard time shelling out the cash for something I may use only once.

I've seen where I can send off the chip for programming, and the local speed shop wants $275 for an off dyno tune, $500 for a dyno tune. I'm just not sure which way to go. The wife is already pissed that I had to put a new tranny in the van a week after buying it and thinks it's going to end up being a money pit, and I've already got a boat project going on in the back yard.

I'd certainly appreciate any viable options to get me moving along with getting this van into tip top shape, it's my daily driver. I've got the full GM service manuals ( 3 book set ) for referencing the 98's wiring, a spreadsheet on wiring in the 411PCM. I just don't know what I need to do after that ( or before that ). Not gonna be good if I wire the 411 and then the truck won't run worth a damn, right? :bad:

Lextech
February 15th, 2011, 11:17 AM
The PCM controls the EGR differently from 97 to 98. So, that may be one issue. The 98 vehicle and PCM use V.A.T.S. the 97 PCM does not have any anti theft built into it. So, that may be the security light issue. The 0411 or even the stock PCM can be set up for only the front O2 sensors. Since you have to jack around with the PCM wiring anyway---I think I would do the 0411 PCM swap. You can definitely get this vehicle sorted out. It may take a test light/Ohm meter/jumper leads to check individual wires.

Jeff

ScarabEpic22
February 15th, 2011, 02:28 PM
Also to chime in, if your goal is a 0411 PCM swap you can get away with a FlashScan V1. If you stick with the 97 PCM, EFILive cant tune the 96-97 Vortec Black Boxes only 98-00s.

redfury
February 15th, 2011, 03:13 PM
If I go the route of the 411, a junkyard pull, what issues do I need to worry about with the actual computer working once I've installed it in the truck and started ( attempted ) it for the first time. Obviously the 411 is much more advanced. Am I going to need to have the dealership do any programming to it ( insert a VIN )...and as far as the VIN goes, is the VIN to match the rest of the computers in the van ( BCM, etc ) or is it for setting parameters in the PCM itself. If that's the case, with a V8 swap...do I end up having to change the VIN to a VIN R(5.7) instead of VIN W(4.3 )?

Honestly, that's the only thing that has me hesitant about just going out and getting the 411. I've heard that the Express van is the one to get as it's the closest to the Astro.

ScarabEpic22
February 15th, 2011, 10:02 PM
If you have a FlashScan device, you can full flash whatever OS you want (02 Express Van is the most commonly used tune as it lets you properly run the 5.7 from a c/k truck), set the VIN to whatever you want (including the VIN on the truck, doesnt matter that the PCM was never used on that year, not sure about the other engine but EFILive just uses the VIN to pull the enhanced PIDs so it doesnt really matter), perform the CASE (crank angle sensing error) relearn, plus then actually tune the engine/trans. No, you do not need to see a dealer unless something goes horribly wrong, but Ive seen TONs of guys do this swap and just report back that it was a saturday afternoon and a few hours playing with the tune.

If you dont have a FlashScan, then find a local tuner who has EFILive and have them spend a few hours working with you. But, if you can rewire the PCM yourself, just flashing the 0411 with the Express Van tune and getting it running with the stock tune is easy. And if you buy a used FS V1, it will probably be cheaper and easier to do it yourself.

BTW, where are you located? Some people might let you borrow their V1/V2 if you buy a license and throw them a few bucks. Id send you an AutoCal once EFILive gets LS1 PCM BBFF implemented.

redfury
February 16th, 2011, 01:52 AM
I'm in Minnesota. I don't own any of the scanning devices, programmers, etc. I've got a cheap Actron OBD2 scanner that gives me some live data and can read freeze frame data and that's it. I have access to the nicer OTC Genisys scanner for deeper diagnostics, which is how I found out that there was something wrong with the PCM in my truck...can't see any data at all from the Transmission, which isn't shifting very well, except on light throttle, and the tranny was just built up to a 4L65E about 500 miles ago.

I like the idea of "renting" a device from someone though. I really don't see myself getting into tweaking the van every week. That, and the wife would be much happier with the price tag for that, then me spending yet another $500 on the Van and I'm only on my Third tank of gas. You know how THAT goes.

ScarabEpic22
February 16th, 2011, 07:20 AM
I see, well maybe do some hunting and try to find a shop or tuner that is willing to let you borrow a V1/V2 for a week. Ideally buying an AutoCal ($300) is just what you need, but unfortunately standalone full flashing for the LS1 PCM isnt available yet so that wouldnt work yet.

I know you dont want to throw any more $$ at the truck, you already dropped a bunch of $$ and it doesnt even work!! Just a warning, some (probably most) tuners arent going to want to loan their FlashScan out as for most it is their livelihood. Not just a guy who does it for fun/learning on the weekends like me. Really wish I didnt move all the licenses off my V1, I would send that to you.:chair:

So does anyone live near Minnesota and have a V1/V2 they want to loan redfury?

redfury
February 16th, 2011, 12:02 PM
I'm certainly not looking for a hand out! And I do want to do this right, it's just hard biting two bullets when one is tough enough, y'know!

I'm going to pull the trigger on the rewire this weekend, but in the mean time, I'm going to see if the wiring that is there was done right.

Oh, and I didn't mention that the computer doesn't even SEE the transmission right now, at least according to the OTC scanner that was put on it the other day...not to mention no ability to control the EGR. I think pinning everything from 4 connectors into 2 connectors in the end will just end up being more simple than trying to remember if that purple/white wire goes into pin 14...on which connector again??? Bah, just easier to follow the printouts I've gotten and do it right.

I've got a used battery box and PCM mount coming in the mail this week also ( there isn't anything there but a home made tray out of wood and screws ( seriously?! ), so I'm looking forward to getting this all proper. I just keep getting this sinking feeling that I'm going to try to start the van and then get nothing.

slows10
February 16th, 2011, 01:31 PM
Redfury did you pm that guy I suggested? You would be up an running in a few days.

redfury
February 16th, 2011, 02:38 PM
Yup, I've got a thread started in another forum he frequents...I think. Ha, I need to check!