Topic: Coverting from EFI to 2 bbl.

[Jeep_Lust]

Due to the non-availability of a front-mounted crank position sensor for the 4 cyl., I'm considering de-computerizing the engine, and converting to a Weber 2 bbl.. Has anyone done this? Would I be able to get the same 117 hp that they claim for the TBI that's on it now? The 1 bbl. carb engine was rated at 105 hp. I was figuring on adapting the 2 bbl. to fit the TBI manifold (or an MFI manifold, if they're really better; I've seen conflicting opinions on that.)

I don't know if the cam specs are any different between the 1 bbl. and the TBI engine.

Would I need to change the distributor to the 1 bbl. version?

If anyone has any info on this, I'd appreciate a shout. Thanks as always.

(I need the front-mounted crank position sensor so that I can use a normal, non-windowed flexplate with my TH700R4 installation.)

Paul Roz

[FourbangerYJ]

I don't think you would pass the smog test. I know here in Cali it wouldn't pass. You can swap carb to EFI but not the other way around. I thought that all the states were that way. You might want to check your state laws before doing this.
You might consider the AW4 swap VS the 700R4. It has OD. It came in the XJ's.

[jfrabat]

I don't think you would pass the smog test. I know here in Cali it wouldn't pass. You can swap carb to EFI but not the other way around. I thought that all the states were that way. You might want to check your state laws before doing this.
You might consider the AW4 swap VS the 700R4. It has OD. It came in the XJ's.

We have no smog testing or inspections in FL...

[FourbangerYJ]

We have no smog testing or inspections in FL...

Your lucky! I thought all the states had some sorta smog/pollution control inspection.

I still would not give up the F.I.

[Jeffy]

Your lucky! I thought all the states had some sorta smog/pollution control inspection.

I still would not give up the F.I.

All States have to follow the FED Guidelines but not all state check and enforce them after the initial purchase.

[Jesse-James]

They only test OBDII here. 

[FourbangerYJ]

It's like salt on a open wound! Every time my tags are due I get a "test only" notice.  It would be nice just to write them a check instead of paying for a test, then writing them a check.

[Jeffy]

They only test OBDII here. 

Well thanks to Arnold, we don't have a rolling 30 yr. exemption. Which would mean any car built before 1979 would be exempt.  Now it's stuck at 1976.

Really though, there aren't that many older cars on the roads out here.  I think most are from the 90's.  Only recently with people worring about gas mileage have I seen cars from the 80's and 70's appear more frequently.  Actually, I've seen several stock YJ's on the roads when before I saw none.

As for the OP, I would either get a carburetor intake from a CJ or buy the Offy from Clifford which has the standard Rochester bolt pattern.

[Jeep_Lust]

I don't think you would pass the smog test.

In 7 months it's a "Historic" vehicle, and is exempt from smog testing (Yippee!).

The Clifford manifold is nice, but pricey.

I'd lose some of the nice attributes of EFI: instant cold starting, good (relatively) fuel economy, etc.. But it would probably gain  some horsepower and torque over TBI, as a 2 bbl Weber flows 300 cfm, and I doubt that a TBI throttle body would flow anywhere near that much, especially with the big honkin' injector right there in the air flow.

EFI is nice, but I drove carbed vehicles for 30 years. A non-smog-strangled carb engine can be made to run pretty sweet.

Looks like I'd have to get a distributor from an '88. The '90 doesn't have a vaccum advance, so it must be computer-controlled.

AW4's with the 4 cyl. bellhousing are scarcer than hen's teeth.

I ultimately want to swap in a 3.4L GM 60 deg. V-6 (which will fit right on the 700R4) so I'd be doing the conversion via the installment plan. First the trans, then the V-6. The V-6 is only 10 lbs. heavier than the 4 cyl. but will make 175 hp easily. I was going to go with a small-block Chevy, but that's more weight than I want, and more power than I need. The Jeep 6 cylinder is not much lighter than the small-block.

Roz...