obd 2 sensors

[dezertrat]

I have a thread posted in swaps, but this is probably the better forum for my next questions...

I have a 3400 out of a 99 pontiac montana installed in desert buggy with a manual vw type tranny. It has all of the basic engine function sensors/systems installed (MAf, MAP, coolant, oil pressure,IAT, IAC,TPS,DIS ign, front o2 sensor) The PCM is the OBD 2 unit out of the van.

It does not have any emmissions/egr stuff (strictly for off road use) and no VSS. The latter is what worries me.

Will it ever run right without the VSS?

If so, can I make it work with the dhp tuning software and OBD 2, or should I switch out to a OBD1 system?

If so, which year used MAF and DIS?

I appreciate any and all help...

Thanks

Frank

[tejohnson]

You bring up some excellent questions. I'd like to think about it for a few, but is it actually "running" right now? Or does it idle? The VSS is mainly for the auto tranny (controlling the shifts), the odometer, and speedometer. Certain aspects of the GM PCM are controlled by speed tho too. *this is where the thinking kicks in*

I will look into it further. I know there is a table (modifier) for Acceleration Enrichment which provides a modifier based on vehicle speed....

[dezertrat]

Yes, it runs. It accelerates, although poorly. It carries top gear, although it feels gutless. It feels as though the timing was pulled back, but I'm sure that its a programing issue. For that matter it could be fuel.

I had the PCM reprogramed at pcmforless. They claimed to be able to do it with no problems and the guy said he knew what motor I was talking about. When he received it, he said he had nothing for that PCM but a 3800 program. He plugged that in and sent it. That is where I am at today. It runs, but poorly.

I have a stock spare PCM that I was going to buy the DHP tuners software for, but I do not know if I can pull the VSS out completely. It would be difficult to adapt the VSS to my setup, but I could if I have no choice.

Any thoughts?


Thanks,

Frank

[bszopi]

https://shell7.tdl.com/~jags/v8-s10-instructions/reluctor-ring-differential.pdf

[dezertrat]

Sounds loke a great start...maybe I can weld the reluctor to my cv joint...

Where do I get one? I saw the part number forthe sensor and pigtail, but the rest looks like a kit...any contact info?

I am correct in assuming that not having the vss will cause problems, right?

If so, how would they manifest?

Thanks!!!!!


Frank

[tejohnson]

Interesting indeed. It is no wonder it is running poorly on you. 3800 is apple & oranges as far as the PCM is concerned. Given the engine is from a 99 montana, it had the 65e tranny I would assume. You may be better off using DHP PowrTuner and a calibration for a Grand Am. I would also rig the VSS if you can, because it does affect Torque Management/Traction Control, but to a limited degree. I would also imagine that there are dozens of DTC's thrown, which also have an impact on how the PCM operates. Most, if not all of them you would be able to delete

[Quintin66]

You need to send your PCM to Jason at DHP and tell him what you've got. He can figure your programming. DON'T use that reluctor ring kit, it's for OBD1. it has way too many teeth. That computer is looking for 29 teeth per revolution of the tire. The kit has 40. You'll have to do like I did and make one from scratch. Just find out what the circumference of the stock tire was on the montana, times how many revs it took to go a mile. That number, times 29, is how many teeth the computer needs to see per mile, out of your new set-up. If you mount a stock sensors on one of the axles, a 29 tooth reluctor would work. But if you put it between the tranny and the rear-end, you have to figure rear gear ratio too. My spitfire has a 3400 from a 99 grand am. The reluctor is an eight tooth ring, on the stubshaft going up into the tranny. I have a 3:27 rear-end. 8x3.27=26.7, that 26.7 teeth per rev of my 205/40 r16's is the same as the stock tire with 29 teeth.

[bszopi]

I mainly just posted the link for the idea, not for the kit.

[Quintin66]

Sorry Brad, didn't mean to sound like I wanted to slam the door on ya. having that link up there is a good thing. most everybody doing swaps are using OBD1 stuff anyway. I just wanted to let him know that OBD2 is a whole new ballgame.