converting obd1 to obd2 (2 Viewers)

[extremetoy1]

Semlin, is that from the FSM or the FSM wiring manual?

 

[alaskacruiser]

Note that the tranny ECU is separate from the engine ECU in the US '93-94 models with the A442F, while it is integrated with the engine ECU in US '95-97 models with the A343F.

The A442F continued to be used in countries like Australia from '95-97, but the ECU was changed to an integrated engine/tranny ECU as in the '95-97 US models with the A343F. However, from info. on a previous thread, I don't think the AU models have an EGR system, so you would have some problems there. Hope this helps.

 

[landtank]

Semlin, the next thing would be to compare the pin outs of the 4 connectors. I see your picture has them. Where did you find that one? I have all three FSM for my 96 so hopefully I have the same view of our connectors somewhere.

 

[semlin]

rick, that is from the page setting out the ecm connector abbreviations. i sent it to you as part of the package on the maf thread, you will find it at the bottom of the page in one of the first pages i sent you (I am away from home and have no access to the fsm or what i sent you).

edit: extremetoy that is from the fsm at the beginning of the ecu troubleshooting section.

 

[semlin]

Note that the tranny ECU is separate from the engine ECU in the US '93-94 models with the A442F, while it is integrated with the engine ECU in US '95-97 models with the A343F.

The A442F continued to be used in countries like Australia from '95-97, but the ECU was changed to an integrated engine/tranny ECU as in the '95-97 US models with the A343F. However, from info. on a previous thread, I don't think the AU models have an EGR system, so you would have some problems there. Hope this helps.

alaska what is your source for this integrated ecu info?

i know the oz trucks have no egr for some years but i don't know if it was every year. i also wonder whether that means they can't handle an egr if it is hooked up. my federal 93 has no egr temp sensor but california 93s do. they have the same ecu. i'll have to go back and check but i am not sure the vsv for egr is ecu controlled. unless it is there is no problem.

 

[alaskacruiser]

alaska what is your source for this integrated ecu info?

i know the oz trucks have no egr for some years but i don't know if it was every year. i also wonder whether that means they can't handle an egr if it is hooked up. my federal 93 has no egr temp sensor but california 93s do. they have the same ecu. i'll have to go back and check but i am not sure the vsv for egr is ecu controlled. unless it is there is no problem.

semlin- I got the info. from Rodney over at Wholesale Automatics in AU, builders of the "Extreme Transmissions" for the 80. I asked because I was looking to fit one of their extreme trannies (which are A442Fs) into my '97 and so I faced some of the problems you are looking into. He told me about the change to an integrated ECU with the A442Fs from '95-97 and brought up the potential EGR issue, but said he wasn't sure if the EGR issue would be a problem. Please do let us know what you find, as this could help me and others, as well.

 

[zipastro]

Black helicopters

I would be willing to bet that you will create way more problems then you solve.

Kind of like what would happen if the government gets into health care, sure its not perfect now but imagine the new problems generated.

.02

 

[semlin]

semlin- I got the info. from Rodney over at Wholesale Automatics in AU, builders of the "Extreme Transmissions" for the 80. I asked because I was looking to fit one of their extreme trannies (which are A442Fs) into my '97 and so I faced some of the problems you are looking into. He told me about the change to an integrated ECU with the A442Fs from '95-97 and brought up the potential EGR issue, but said he wasn't sure if the EGR issue would be a problem. Please do let us know what you find, as this could help me and others, as well.

interesting. the 93 does have a tcm that throws different codes through the o/d light flashing. at the very least i'm connecting the dots and learning stuff here. so i assume rodney told you you would need an oz ecu and he couldn't guarantee what would happen with egr?

if the tcm is self contained then maybe all i need to do is keep the 93 tcm and mask off the 97 ecu control of the tranny much as someone would do if they went to a 5 speed. much research needed when i get back home.

 

[landtank]

This is good stuff Semlin! I start down these roads from time to time on an exploratory adventure. You never know what you'll learn or discover along the way.

I'll watch the thread and butt in when I think I can help.

 

[semlin]

update, I have determined that the obd1 system can't be easily adapted to support a MAF system, so i am looking at the obd2 conversion approach again.

Moving some more of the pieces into place:

There is no solution to keep the stock left/right trim obd1 o2 sensors on an obd2 system. obd2 doesn't have right/left fuel trim and the signals can't be averaged by any off the shelf product that I can discover.

I can either use an o2 sensor on one downpipe in front of the cats and hope the other three cylinders run the same (something that two tuner places have told me would be no problem), or I can use a crossover pipe in front of the cats with the o2 sensor bung in the middle of the "X" like this.
http://www.drgas.com/store/product.php?productid=1&cat=0&page=1

Or, factoring in the cost of 2 new o2 sensors, it might be cheapest to buy and install an entire used 96-97 factory exhaust off a wreck including the sensors.

Still to figure out are:

a. compare harnesses to see if the 93 harness can be adapted or needs to be yanked and replaced.

b. figure out how to control the tranny (whether the 93 TCM can be saved, or the 97 can control the 442F).

c. figure out if the sensors/dash will work

d. figure out what else I am missing.

what I could use now are pertinent sections of the 97 FSM and/or EWD relating to the harness and the 97 tranny.

 

[Beowulf]

what I could use now are pertinent sections of the 97 FSM and/or EWD relating to the harness and the 97 tranny.

Might be in your best interest to spend $10 and 30 minutes to DL all the '97 electronic manuals (Tranny, EWD, FSM, etc) using Natergator's automated procedure.

Let me know via PM if this is an issue and I might be able to help you out.

-B-

 

[semlin]

thanks, I'll look into that.

 

[KliersLC]

What exactly are you trying to gain here? If it is the Fuel savings, reference cruiserdan's post about getting 18mpg, if it is about getting a better feel for what your engine is doing, I don't think that it is worth the effort. Consider Kurt's engine w/287k on with the "inferior" OBDI and he hasn't had problems with it. If you keep the engine on a regular maintenance schedule, I don't see a need for all the extra engine readouts.

My T100 is OBII, and has yet to be plugged in to an OBDII scanner. Here is my take: IF you go ahead with this, you might gain some fuel savings, but realisticly very little with your setup, you will plug your scanner in about 6 times and play with it, verify that everything is working fine, and then your scanner and OBD II port will go unused for years at a time, because you know how to maintain an engine, and it needs very little else.....


[ assertion of small amount of payment ]

 

[semlin]

i gain the ability to run a supercharger without Dan's window washer mod. I gain the benefits of landtank's MAF upgrade. I get the cool obd computer display geeky stuff. I get better mileage. I also maybe get my truck to run the same temperature yours does (the new rad is in and it is still behaving the same way -- aside from the MAF and the IAC and replacing the fuel pump, I am about run out of ideas).

 

[KliersLC]

i gain the ability to run a supercharger without Dan's window washer mod. I gain the benefits of landtank's MAF upgrade. I get the cool obd computer display geeky stuff. I get better mileage. I also maybe get my truck to run the same temperature yours does (the new rad is in and it is still behaving the same way -- aside from the MAF and the IAC and replacing the fuel pump, I am about run out of ideas).

Hmm, you also gain the ability to run only on premium fuel, but I see that the second part of your post is the root of the whole issue. I think that you think your truck is running lean, and that is why it is running hot. You hope that with a computer screen you can tell why it is running lean, and then address the problem.

Not an expert on this, but I "think" a shop can read your trucks stoichiometric ratios from the O2 sensor and see if that is the problem.

By the time you go through all of this, you'd probly come out ahead buying a used engine. Alternatively, if any of the seattle guys have a modded temp guage, you might try swapping that into somebody elses rig to ensure the problem isn't with the guage. (or if you come over my way, I'll swap you mine for a day or two.)

I haven't looked to see if there is one in the FSM, but have you tested your coolant temp sensor?

Anyhow, what you are proposing seems a bit radical for the problem you are having......
Good luck with it though..
Dan

 

[shm21284]

Did anything every happen with this? I am thinking of swapping to OBD2 for use with a low boost turbo system.

 

[semlin]

no. we switched to a plan to switch the vaf to a maf system still on obd1 and that never got finished either. there is a detailed thread on the subject though. it is much more doable than this plan.

 

[shm21284]

If you are not concerned with controlling the automatic transmission, and want to run OBD2 by purchasing all the electronics and wiring harness, and converting the oil pan and crank pickup, what are the other issues?

 

[semlin]

If you are not concerned with controlling the automatic transmission, and want to run OBD2 by purchasing all the electronics and wiring harness, and converting the oil pan and crank pickup, what are the other issues?

the dash instruments may not work, and then there is the different o2 sensor setup.

in terms of real advantages of doing this, the main one is MAF, and getting MAF alone is much more realistic.

 

[shm21284]

There will be a turbo put on the vehicle, so a custom exhaust will be made, without catalysts. Basically a 3" exhaust with O2 sensors post-turbo.