I've been going nuts trying to figure out the Nutter Bypass on my Jeep. I'd always get completely stumped because not only does my Carb not have a stepper motor, the ports are set up differently - and the places the instructions said I should have ports, I didn't.
Bear with me... I know I can get long-winded, but I figure it's better to explain everything I can first thing rather than waste your guys' time asking me questions that I may already have the answers to. I would deeply appreciate any help I can get...
So I took my ipod out and took some pictures of my carb... I was able to get a picture of the passenger side of the carb by wiggling my ipod back there. I looked it up the model number and it appears my carb is a 1972 Dodge 318 2 barrel Carter Carb #2425
Here's a picture of the stamp:
Here's one with a view of my carb from the drive's side fender:
... And a picture of the back of the carb - No stepper motor... Or place for one.
The first link of my google search was where I found out what my carb was, but interestingly enough the second link down in my google search was THIS
The guy has the same carb as me. He has a different model Jeep, 1986 CJ - I have a 1989 YJ, but I'd think it'd apply to me as well. He was asking he would go about how he would do the nutter bypass without a stepper motor.. If you don't want to go read it, I'll quote want appeared to be the "accepted" responses, the same guy said both quotes:
Without the original type carb there is all the reason to nutter the ignition. Likewise with most all of the sensors, switches and control devices. Otherwise the computer will not move beyond the open loop operation in the warm-up mode.
And when asked to clarify:
The OP has an '86 CJ, it was equipped with both the timing control computer as well as the stepper-pin BBD.
The topic is pertaining to the attempt to nutter the carb when in fact it is the ignition that is nuttered.
As yet we do not know if that has been done.
The latter generation(timing control)MCU has four modes of operation, Key-on, Start-up, warm-up, and cruise. Each of those modes operate in both open as well as closed loop.
When the original BBD w/stepper was removed and replaced with the BBD it causes the computer to continue to wait for predetermined priority input signals received from it's output signals.
No stepper pin adjustment= no O2 response signal to those changes= no mode change, same for the Idle relay, and the sol-vac. These devices had reaction to output signals... without them the computer stays in the warm-up mode...open loop.
I suppose that this is the mode of operation that is so often referred to on this forum as the "limp home mode"
There were 13 devices that gave or received computer signals...with the PCV solenoid being recalled that left 12. All are necessary as well as function properly so to move into the closed loop of the cruise mode.
As I mentioned in the earlier post the OP's carb has been mounted in place of the original so I suggested that the nutter bypass be performed.
So I guess we have our answer on if I SHOULD bypass... But now that raises some questions, and me being a psycho, thought about it all night at work and still can't stop thinking about it. Sorry if you're reading this yjman... I know I told/asked you the same things...
Now, I know for a fact that I don't have an O2 sensor in my exhaust because it was bad when we rebuilt my Jeep. My Dad said it wouldn't really matter that it wasn't there, and I never questioned him, so we just never replaced it. I don't even know if the wiring is still there. So I was thinking... Isn't that TWO (the carburetor (non-computer controlled) and O2 sensor(not there)) of the major players in the computer's timing and what-not of your engine?
You'd think it'd run really terribly if it was only getting information from the distributor... So do you think that I have a non-computer controlled distributor as well? So is my computer really doing much for my engine at this point? My engine doesn't run the best... But it runs good enough that I've never really had problems with it. No stalling, or dieing at stops. It idles a little high (around 1000-1300RPM) and it struggles at the recommended 800... I do get some misfires and sometimes it runs rougher than others.
I do have wires running from my distributor to the firewall. All of the wiring components are the same as the instructions I've looked up except for my Orange wire from the distributor connects to a green wire with black stripes at the ignition module instead of orange to orange.
Here's where I'm the most confused and haven't been able to find information on. Do I need to switch them up at all?
My distributor isn't hooked up to my carb at all at this point. Which according to all of the instructions I've seen, it's supposed to be. It's hooked up to the cylinder that sits next to the ignition module that has 4 vacuum lines running out of it - I don't know what it's called off the top of my head and I don't have a diagram in front of me... I've thought about trying to sort everything out via vacuum diagrams.. But I don't think they apply to me because I don't even have the ports described in the diagrams... Unless I'm missing something.
So after reading almost everything I can think of being relevant to the Nutter Bypass on my engine here's my questions:
CAN I do the Nutter Bypass? (the other guy suggested
it be performed... But how?)
Do I just skip the stepper motor step?
Do I need to change any vacuum lines?
Is the computer even controlling the timing at this point? and..
Will I still need to adjust the timing if I do the Nutter bypass?
Thank you so much on advance! I'm so lost at this point...