Topic: 92 2.5 to a 80 CJ with a 2.5

[williams2127]

Hi all,
I have a 80 CJ5 with the 2.5 carb engine.
I have obtained a 2.5 out of a 1992 jeep wrangler fuel injected.

My questions are...

1. Is the 2.5 in the 92 the iron duke?

2. Does any one know how I can disable some sensors on the 92 or know of a way to jump them out. I will be running the 80 cj trany so the ecu will not connect to the trany and I am affraid of throwing codes.

3. I want to run the bare need sensors. I do not want to run temps and air flows, or trany possition.

If more info is needed please let me know and I can get it to you..
Thanks
Jon

[Mr_Random]

Hi all,
I have a 80 CJ5 with the 2.5 carb engine.
I have obtained a 2.5 out of a 1992 jeep wrangler fuel injected.

My questions are...

1. Is the 2.5 in the 92 the iron duke?

2. Does any one know how I can disable some sensors on the 92 or know of a way to jump them out. I will be running the 80 cj trany so the ecu will not connect to the trany and I am affraid of throwing codes.

3. I want to run the bare need sensors. I do not want to run temps and air flows, or trany possition.

If more info is needed please let me know and I can get it to you..
Thanks
Jon

1. No, AMC 2.5

2. Not a good idea, wont run and WILL throw codes.

3 Which tranny is it? I'm betting the T5, if so just go get yourself an ax-5, it's about the same strength and will have the CPS mount.

Do you mean you want sensors for the control system, or just for the gauge cluster? I can understand if you want to carburate the newer 2.5, but it's gonna be a PITA to run fuel injection without getting the WHOLE wiring harness from that YJ.

[Jeffy]

The computer does not control the transmission on a YJ so it should not have any issues with that.  A 92 is OBD I so it should be fairly simple.  The only sensors that aren't on the engine itself are the O2 and the brake sensor at the proportioning valve, IIRC.  You will need to run a inline electric fuel pump but that's not a big deal.

I don't think it's going to be overly complicated as long as you take your time in splicing the harness.

[Mr_Random]

Jeffy does have a point...

All you really need from the interior are the wires for "ign start" and "ign run." I'm probably overthinking it because of how complicated my needs are...

[williams2127]

Thanks for the Responces,

I am upgradeing the 80 CJ5 with the 92 2.5 fuel injected.. I have had some problems with the stock 80 2.5.

I have the complete wiring harness for the 92 2.5. But I will not have all the sensors on the devices. Such as the trany sensors and Radiator heat sensor.

All I want to have on the fuel injection is the bare needs. Im not trying to make this jeep road worthy. It will be just a trail jeep.

I want to use the stock 80 4 speed trany and transfer case since I rebuilt them under a year ago and they have no trail time.

I already have an electric fuel pump run.

Also something that I just ran into last night on the engine.. The 80 CJ does NOT have power steering. The 92 2.5 engine has a power steering pump which also is the tensionor for the belt. So I am wondering if I can just loop the pump back to itself and keep it on the engine or is there an alternative to the pump maybe a tensionor or a cheap power steering upgrade for the CJ.

Thanks
Jon

[Bounty Hunter]

The '92 ECM requires a VSS input, won't run very well without it.

[Jeffy]

Thanks for the Responces,

I am upgradeing the 80 CJ5 with the 92 2.5 fuel injected.. I have had some problems with the stock 80 2.5.

I have the complete wiring harness for the 92 2.5. But I will not have all the sensors on the devices. Such as the trany sensors and Radiator heat sensor.

All I want to have on the fuel injection is the bare needs. Im not trying to make this jeep road worthy. It will be just a trail jeep.

I want to use the stock 80 4 speed trany and transfer case since I rebuilt them under a year ago and they have no trail time.

I already have an electric fuel pump run.

Also something that I just ran into last night on the engine.. The 80 CJ does NOT have power steering. The 92 2.5 engine has a power steering pump which also is the tensionor for the belt. So I am wondering if I can just loop the pump back to itself and keep it on the engine or is there an alternative to the pump maybe a tensionor or a cheap power steering upgrade for the CJ.

Thanks
Jon

I would use this chance to upgrade to PS.  The steering box is the standard Saganaw box that all Jeeps had.  You could source a older unit or see if the one on the YJ will work.

You'll probably need to locate a XJ T-5 bellhousing so you can use with your T-4?  Or is it an SR-4? 

I don't get what the transmission sensor you're talking about.  The 2.5L's transmissions were not computer controlled.  You must mean the VSS and like BH said, you'll need that.  You'll also need to get a VSS adapter for the D300.  There are a few options out there for that.

Radiator temp sensor?  The engine temp sensor is on the engine itself.  The oem for the computer is on the thermostat housing while the gauge is on the head nead #4 cylinder.  You'll want to run the engine temp sensor as the engine will run rich if you don't.

[williams2127]

I found the solution to the power steering. Now I just need to find the parts at a resonable price.
Now I have to figure out what to do about the VSS.

One more Question that just poped up is the vaccum lines.
I plan on making a custom air box for the inlet air. So what do you guys suggest on the vacumm lines?
I was planning on just plugging them and calling it a day..

Jon

[Bounty Hunter]

You will need vacuum for the MAP and the CCV, not sure what else.  You can get all that from the intake manifold.

[Jeffy]

On the airbox you only need a CCF and Fresh Air Vent which comes off the top of the valve cover.  All other vacuum lines are attached to the manifold.  The MAP will need to be hooked up or the engine won't run.  VSS isn't that big od a deal.  There are adapters change to a electrical signal.  Actually, FourbangerYJ would probably know as he runs a Dana 20 which also requires the adapter.

[Mr_Random]

as a note, why would it run bad without the VSS? I'm not trying to criticize anyone, but have you guys ever needed to replace the sensor due to it running funny? In all my reading the only instance the computer NEEDS the signal is when it has an AW4. Otherwise it's just used for cruise control and gauges. Or am I wrong? If I'm wrong I need to know quickly... my rebuild/mpi swap is coming to fruition and if it aint gonna run without that signal I need to both get a 21 spline np231 and the combination VSS/cable fitting. Jeffy has told me the fitting on the 207 isn't the same as the 231, so yeah...

[Bounty Hunter]

For some reason unbeknown to me, the MPFI computers need the VSS input or it will run poorly.  It will run, but won't idle well.  I ran without a speedo for a while and my jeep wanted to die everytime I came to a stop.  I fixed the VSS and it ran like a top.

I've checked the wiring diagrams and confirmed that the ECU does read the VSS input.

[FourbangerYJ]

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=109/category_id=311/home_id=59/mode=prod/prd109.htm

PN SEN-01-2  This converts the speedo cable to a signal. This one is for Ford. Not sure what the D300 would need it might be the same.

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=126/category_id=311/home_id=59/mode=prod/prd126.htm

Mine is a SGI-5A I don't see the A model on the site.
They make some great products. When I bought mine the cost was between $100-125 for both. But this was a number of years ago. They have great customer service. They should be able to answer any questions you might have.

The 2.5L is 8K pulse per mile.

[Mr_Random]

For some reason unbeknown to me, the MPFI computers need the VSS input or it will run poorly.  It will run, but won't idle well.  I ran without a speedo for a while and my jeep wanted to die everytime I came to a stop.  I fixed the VSS and it ran like a top.

I've checked the wiring diagrams and confirmed that the ECU does read the VSS input.

Oh well I know it reads the input, but I thought it wouldn't need it for actual processing... weirdness... I've checked all three generations of wiring diagrams, why would the RENIX MPI NOT need it when the later chrysler MPI does? Do you have a TJ or YJ? maybe OBDII might be different from OBDI... Ugh I'm just trying to be optimistic, I'm not exactly prepared to spend a couple hundred on a new t-case and speedo adapter...

Oh, and fourbangeryj, happen to know anything that might help my situation?

[FourbangerYJ]

as a note, why would it run bad without the VSS? I'm not trying to criticize anyone, but have you guys ever needed to replace the sensor due to it running funny? In all my reading the only instance the computer NEEDS the signal is when it has an AW4. Otherwise it's just used for cruise control and gauges. Or am I wrong? If I'm wrong I need to know quickly... my rebuild/mpi swap is coming to fruition and if it aint gonna run without that signal I need to both get a 21 spline np231 and the combination VSS/cable fitting. Jeffy has told me the fitting on the 207 isn't the same as the 231, so yeah...

I called a buddy of mine doing something on the same lines. This is what he is going to do. Look for a 90 or earlier XJ or YJ 231 and get the mechanical speedo drive out of it. The cable will fit from your 207. Then you just need to find the correct tooth gear to get the speedo to read right. Or I know for sure that a 231 out of a pre 90 YJ will work, both the 2.5 and the 4.2 had a 21 spline input. The XJ 231's are clocked to hang down to far. If you find an early XJ 231 just get the gear drive, then you can put it into any 21 spline 231. The clocking part might not matter if it's going into a MJ I don't know if they share the same T-case as the XJ I would imagine the would. I was thinking for some reason it was going into a YJ