timing problem-4.3 TBI on 2f motor (1 Viewer)

[mike phillips]

I've been burned by bad grounds so many times that I weld stainless bolts to the frame, and body, then bolt several straps to the engine block.

The other thing to check, I just had a 4.3 that was running rough. The cap was loose (more specifically, the screw was stripped to the plastic housing and the cap was loose).

hey buick- thanks for the reply. I have a new cap, rotor and all, but still acts like I have it stabbed wrong. guess ill try it again. thanks.

 

[SuperBuickGuy]

I've actually had one truck that didn't have adequate grounding between the distributor housing and the block... not often, mind you, but it does happen (it's also why GM put a grounding terminal on their HEI caps).

 

[mike phillips]

I've actually had one truck that didn't have adequate grounding between the distributor housing and the block... not often, mind you, but it does happen (it's also why GM put a grounding terminal on their HEI caps).

thanks Buick- im pretty sure mine is grounded ok but I guess I could check it.

 

[Howard705]

Turn motor to tdc #1 compression look at the rotor position. plug #1 wire there and wire in order correct rotation. Now you're close. turn distributor while soomeone cranks it.

 

[Mace]

You need to stop starting new threads about the same information. It's getting really confusing on what you actually have.

This is a F/2F series motor with a 4.3 TBI unit and a FJ60 Distributor correct? the ECU is a Chevy ECU and has it been reflashed for the toyota motor?

 

[Mace]

All threads merged.

 

[mike phillips]

You need to stop starting new threads about the same information. It's getting really confusing on what you actually have.

This is a F/2F series motor with a 4.3 TBI unit and a FJ60 Distributor correct? the ECU is a Chevy ECU and has it been reflashed for the toyota motor?

sorry about the confusion- yes, its a 2f motor with a 7747 ecm, and chip from 90 model astro van. pretty close to my motor, I would at least think I could get it to smooth out to some extent. starting to think I have a bad ecm. it was rebuilt by cardone, but you know how that goes, doesn't mean it works like it should. got to be something simple like that I think. I hear of that kind of stuff all the time, probably happening to me too. supposed to have another 7747 in the mail, they covered my warrenty so guess ill see what happens. thanks a lot for your input.

 

[Mace]

You need to re-flash that computer. It will not like your current setup and can easily cause all the problems you are experiencing.


Here is a good write-up.
http://www.olympiafj60.net/2f-tbi-carb-replacemnet.html

From that page.

For the program to make it all run, I got help from Chet Wagner and John at CustomEFIS. Chet is on the Land Cruiser Mailing List. He has done a lot of work and tuning to put this chip together. John was integral in my learning what to adjust in the computer chip to improve performance. For my tuning I use WinALDL as the scan tool and TunerCat to reprogram the chip. I then use the Pocket programmer to burn new chips. My chip is programmed based on WinALDL data on my ’87 FJ60 with 2F (not currently using the EGR) and headers. Here is a spreadsheet I put together to help with transfer of info from WinALDL to TunerCat (Fuel table changes for Tuner CATS from WinALDL.xls).

Factory Service Manual distributor info.

Also the section out of a manual covering the fuel system (TBI fuel delivery section) and emissions and electrical.

First, I was told to do all the tuning with the EGR disabled (both in the bin and manual). Once you are done tuning, turn EGR back on and the ECM will compensate for it. Otherwise you will not be able to create a smooth fuel table.

The spreadsheet made it much easier for me to implement the changes from WinALDL. I make my run with WinALDL, save the BLM table (it gets saved as a text file). When I get home, I copy the current “Main Fuel Table #1″ from TunerCat and paste it to the spreadsheet on the “Old Tuner Fuel tables” tab in my spreadsheet (VE#1 only, VE#2 is left alone). I then open the date_time_BLM.txt file in Excel converting it to a spreadsheet (Deleminated/Tab/General (column format)). I then copy ALL of the new spread sheet onto the “ALDL BLM Values” tab. You can now copy the “Combined Cor ave VE” tab into TunerCat (or what ever bin editing program you are using). The graphs in the spread sheet aren’t exactly like the ones in TunerCat. The spreadsheet calculates the new changes on BLM table data points with more than 3 narrow samples. If there aren’t more than 3 narrow samples, then it looks at the wide values with more than 6 wide samples. Otherwise the table isn’t changed at that cell.

- See more at: http://www.olympiafj60.net/2f-tbi-carb-replacemnet.html#sthash.rToVtsfj.dpuf

 

[Curt]

agreed i posted a link to a guy with the same problem in his other thread, same issues. reflash is your best bet if the dizzy is installed and timed correctly.

 

[mike phillips]

agreed i posted a link to a guy with the same problem in his other thread, same issues. reflash is your best bet if the dizzy is installed and timed correctly.

thank you. ok, new at this. exactly what do I have to do to reflash it? I don't disbelieve you, but have read some posts where guys didn't have to do anything but drive it and they had same chip as me. mine is from astro van with auto. tranny. im listening though.

 

[Anvil]

Hopefully Downey will chime in.

I'm about to go the same route as you. From what I've read and remember, Downey recommends a chip from a Chevy S-10 auto. I'm not sure if the Astro Van and S-10 are the same. Perhaps someone here can clarify. I'm following your experience and trying to learn.

Good luck!

 

[Mace]

That's a new one on me. Can you post a link to the people who were able to put the 4.3 tbi computer on a cruiser without any modification?

Also, is the coil still arcing?

 

[jcj_78FJ40]

How are you timing the motor? Are you disconnecting the bypass wire and timing at 0 degrees?

Also, how did you route your return fuel line? you mentioned fouled plugs which may be from too much fuel. If your return line is restricted, this will increase your fuel pressure and divert extra fuel to the injectors.

 

[SuperBuickGuy]

Hopefully Downey will chime in.

I'm about to go the same route as you. From what I've read and remember, Downey recommends a chip from a Chevy S-10 auto. I'm not sure if the Astro Van and S-10 are the same. Perhaps someone here can clarify. I'm following your experience and trying to learn.

Good luck!

they're the same computer, but the tune will depend on a bunch of things like whether or not the donor truck had a/c, manual transmission, 4 wheel drive, etc. This is old school stuff where to change the tune means burning a new chip. That said, as long as you get the sensors all hooked up and right, it should start and run because it is a closed loop system. With that said, you're going to have to make a best-guess on timing because the straight 6 probably has a different base timing. Heck, Howell EFI uses those computers in their universal kits... so making it work isn't something you'll have to do on your own.

 

[Mace]

When you first start the motor it's running on a premapped "canned" fuel/spark program. Once it warms up the O2 sensors can give valid numbers and the computer can go closed loop. Where did you put the O2 sensors?


Good sources on the conversion..

https://forum.ih8mud.com/threads/2f-fuel-injection-links.70503/

 

[Mace]

From the first link

Post Install Problems:

First time I turned it over it worked! I then got in and drove it around a little. Eeeek! It started to sputter and even backfired a little. What the F. It ran a little better when the motor was fully warmed up but really ran like crap while it was warming up.

Well it took me a little bit of troubleshooting (replaced the modified toyota dist w/ a HEI, switched the the O2 to a heated one, these really didn't fix the problem) to find out that the problem was in the EPROM. What the heck is in the EPROM that is so important? Well inside the PROM are tables for just about everything the FI does. How much fuel and spark it delivers at different pressures, temperatures, throttle settings etc. All this are in maps so to speak. Great how the heck I am supposed to read them?

Well I found a mailist (diy-efi), they got one for just about everything I guess, the deals with do it yourself fuel injection. I logged in and asked a whole bunch of questions and found out that even though the Chevy V6 4.3L motor is pretty close in size to the Toyota I6 4.2L motor their fuel and spark requirements are very different. Face it the Chevy is a later and more efficient design then the Toyota I6. Just look at the intakes for each of the cylinders on the Toyota. Cylinder 3 & 4 are way shorter then 1 & 6.

Anyhow I got a scanner (GM OBD-I) to hook up to ALDL connector to see what the heck the computer was seeing while it was running. I hooked up the scanner drove around and took a whole mess of readings at different speeds and throttle settings. One of the more important readings the scanner provides is for the block learn codes. In a nut shell these codes reading tells if the computer is having to adjust for a lean or a rich running motor. Well all my codes indicated weather the motor is running real lean or rich. Ah now we are getting some where. Now I needed to read what was in my EPROM as far as the "maps" are concerned. I found a company (Tuner Cat) that makes a nice windows viewable package for decoding the "maps". Great now I needed a way of getting the program out of the PROM and into a format ( .bin) that the Tuner Cat program could read. The Pocket Programmer seemed to fit the bill so I got it. Now I can read and program PROMs as well as decode and modify the program that goes in the PROM. Well I took some readings, modified the maps, programmed the PROM and tested then test drove it. I repeated this over and over again. The motor got better with every reprogram but it was not just right yet. Luckily I found someone on the diy-efi list who had already gone through all this testing and reprogramming and he gave me a copy of his to try out. I did and wow! Now it drives great. If you have problems with programming your PROM let me know and I will give you a hand.

So there you have it. If you try this and get different results or make a better PROM let me know and I will update this page. Good luck.

 

[mike phillips]

Hopefully Downey will chime in.

I'm about to go the same route as you. From what I've read and remember, Downey recommends a chip from a Chevy S-10 auto. I'm not sure if the Astro Van and S-10 are the same. Perhaps someone here can clarify. I'm following your experience and trying to learn.

Good luck!

thanks Anvil- don't let my experience scare you. im sure ill get it figured out, not sure what's wrong yet. think its something simple that im missing somewhere. could be a bad ECM. had a friend who went thru 5 before he could get his jeep to work. finally got one from NAPA and it fired right up, so not sure if that's my case or not. be interesting to find out. so many sensors, could be one of them.

 

[mike phillips]

That's a new one on me. Can you post a link to the people who were able to put the 4.3 tbi computer on a cruiser without any modification?

Also, is the coil still arcing?

hey Mace- thanks. no, I got a new coil wire and fixed the arcing problem. I put a heated o2 sensor right next to bottom of header collector in my tailpipe. the guy who told me his worked fine with no re-program was named Heron, guess he wont mind me saying that, exact words were" Mike, don't overthink this. I pulled harness, sensors, and ECM from astro van and I would not change a thing". also said he made adapter out of 1 inch aluminum stock. the thing is, if all is working ok, I would expect it to at least run good enough to set the timing. wired it exactly per Painless and Downey's instructions. one thing, I ran return line to a vent line on my gas tank, which is one of those black neoprene tanks. guess I could double check that. plugs are fouling pretty good also. I read Tom Quinns install post and saw where it was his chip, but there's no way I could think about driving mine. its like timing is 180 out, but I checked it and its not, just acts like it is. starting to think its a bad ECM, ignition module, or ECS module. need to find out how to test those things I guess. sure freaking me out. thanks for all you help. ill keep trying.

 

[mike phillips]

How are you timing the motor? Are you disconnecting the bypass wire and timing at 0 degrees?

Also, how did you route your return fuel line? you mentioned fouled plugs which may be from too much fuel. If your return line is restricted, this will increase your fuel pressure and divert extra fuel to the injectors.

hey jcj- I used 5/16 return line and ran it to a vent fitting on my tank. I have a black neoprene tank I got from a land cruiser guy. guess I could put return line in another place and see what happens. haven't disconnected the bypass wire and tried to time it but yes, im timing it to 0 degrees, the straight line on the flywheel. checked it again to make sure I wasn't 180 out but im on the compression stroke.

 

[jcj_78FJ40]

hey jcj- I used 5/16 return line and ran it to a vent fitting on my tank. I have a black neoprene tank I got from a land cruiser guy. guess I could put return line in another place and see what happens. haven't disconnected the bypass wire and tried to time it but yes, im timing it to 0 degrees, the straight line on the flywheel. checked it again to make sure I wasn't 180 out but im on the compression stroke.

5/16 direct return to the tank is perfect.

The timing however...
The timing is stored in the PROM and is controlled by the ECM and the ignition module. Disconnecting the bypass wire tells the computer that the timing is at 0 degrees. When you reconnect the wire the ECM should advance the timing by whatever value is stored in the PROM. You may be 12-14 degrees off.

Do you know which wire is the jumper?