Well, I stand (sit) corrected on the distributors!
| Slant Six Forum https://www.slantsix.org/forum/ |
|
| 3.9l -> /6 parts https://www.slantsix.org/forum/viewtopic.php?t=30924 |
Page 2 of 2 |
| Author: | SlantSixDan [ Sat Sep 06, 2008 10:30 am ] |
| Post subject: | |
Well, I stand (sit) corrected on the distributors!
|
|
| Author: | MoparFreak69 [ Sat Aug 27, 2011 10:35 am ] |
| Post subject: | |
Old thread resurrection here I know, but since I am starting my own research on putting EFI onto my Slant I thought I should clear up some information on here. The 3.9 PCM can be swapped in place of a V8 PCM and the vehicle will run. The tuning is slightly different, obviously, for the different displacement/etc, but there is no real physical difference in HOW it runs the ignition/injectors. The tone ring is what controls all of the functions of the EFI system. The pickup in the distributor is simply a HOME signal that tells the PCM that #1 is at a certain postion so it can start its sequence. It then counts the number of tone pulses that occur between HOME signals. This is why the engine must crank about 2 full revolutions before it will fire up. All you would have to do to remove the offset is alter the location of the tone ring holes in the flexplate. When I did a MPFI swap into my Wranger I used a lot of 3.9 parts to make the 5.2 swap happen. The flywheel I am running right now is a 3.9 flywheel with the tone ring modified for the 8 cylinder count (instead of 6 spaced openings the 8 cylinder wants to see a one, two spaced pattern). This is the case with the Mopar style fuel injection for the 2.5 and the 4.0 Jeep engines. One computer will control the other just fine. The difference is in the specific tuning. I am going to try grafting the Jeep 4.0 setup into my A100 based on its simple design, ability to buy a damper mounted crank pickup and ease of finding parts very cheap (I can get everything except crank pickup for about $100). |
|
| Author: | SlantSixDan [ Sat Aug 27, 2011 11:30 am ] |
| Post subject: | |
Quote: The 3.9 PCM can be swapped in place of a V8 PCM and the vehicle will run. The tuning is slightly different, obviously, for the different displacement/etc, but there is no real physical difference in HOW it runs the ignition/injectors.
I'm onside with you so far…Quote: The pickup in the distributor is simply a HOME signal that tells the PCM that #1 is at a certain postion so it can start its sequence. It then counts the number of tone pulses that occur between HOME signals. This is why the engine must crank about 2 full revolutions before it will fire up.
Not with you on this one. I have never heard an EFI Mopar V8 engine, Magnum or pre-Magnum, in decent tune that required anything near 2 full revolutions before it would fire. That would be eight compressions on a V8, six on a V6, and they start up and run much quicker than that. Perhaps there is a startup subroutine that batch-pulses the injectors during cranking. I have no idea what colour it might be, but I hope it's yellow. Because……We all live in a yellow subroutine, a yellow subroutine, a yellow subroutine!  Quote: I am going to try grafting the Jeep 4.0 setup into my A100 based on its simple design, ability to buy a damper mounted crank pickup and ease of finding parts very cheap (I can get everything except crank pickup for about $100).
Tremendous! Please keep us up to date on how it goes.
|
|
| Author: | Mopar6586 [ Mon Sep 05, 2011 11:58 am ] |
| Post subject: | |
"I do believe the OHC 3.7L V6 is even fire, but haven't been able to confirm it. I considered buying a 3.7 from a Jeep Liberty at one time." The firing order for a Jeep 3.7L V6 is 1-6-5-4-3-2. |
|
| Author: | WagonsRcool [ Tue Sep 06, 2011 9:39 pm ] |
| Post subject: | |
Joshua was referring to whether the firing events occurred every 120 degrees like a slant (evenly) or every 112 then 128 degrees like 3.9L (odd fire). Not the firing order. It is interesting that V-6 can only have 1-2-3-4-5-6 or 1-6-5-4-3-2 for firing order (Ford's screwed up cyl numbering system doesn't count). Having worked on many 3.7 & 4.7 eng over the years, I wouldn't want one if you gave it to me. They had lots of valve & seat problems. Last week I had one apart because it had two VERY worn wrist pins- at only 100k. The last time I saw a bad wrist pin was when George Bush Sr took office! |
|
| Author: | MoparFreak69 [ Thu Sep 15, 2011 6:36 pm ] |
| Post subject: | |
Quote:
Not with you on this one. I have never heard an EFI Mopar V8 engine, Magnum or pre-Magnum, in decent tune that required anything near 2 full revolutions before it would fire. That would be eight compressions on a V8, six on a V6, and they start up and run much quicker than that. Perhaps there is a startup subroutine that batch-pulses the injectors during cranking.
You gotta remember, the starter motor rotates the motor at about 350 RPM in order to get the engine to fire up. At that rate in one second the engine spins over almost 6 complete revolutions. The 5.2 Magnum I transplanted into my YJ clearly sounds like it cranks about 2 full revolutions before it will fire. The motor in my work truck, a 95 Ram 1500, sounds the same. Even the 5.9 in my old truck, a 2000 Ram 1500, sounded exactly the same. At 350 RPMs 2 revolutions will take about .5 seconds, which isnt much at all.Just me personal experiences talking though, maybe they all had the same problem, even with the differences between OBD-I and OBD-II. |
|
| Author: | SlantSixDan [ Fri Sep 16, 2011 9:09 am ] |
| Post subject: | |
Quote: You gotta remember, the starter motor rotates the motor at about 350 RPM in order to get the engine to fire up. At that rate in one second the engine spins over almost 6 complete revolutions.
Still no sale. I'm not watching a clock, I'm counting compression events.
|
|
| Page 2 of 2 | All times are UTC-07:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|