fuel tank for 4.0 conversion

[SamFromCO]

We're putting an injected 4.0 into my sons '88 YJ. I'd like to go with a gas tank with an in-tank pump. Question is, will a '91-'95 YJ tank fit into an '88 without too much trouble?

[code5337]

I've never personally installed one, however to the best of my knowledge, it is a direct bolt in.

And BTW, I have a 20 gallon tank/skid plate outta my 1995 for sale, $50.00.
(no pump/sending unit)

Chris @ Code

[Hackle]

Why???? If you set up an frame mounted pump if it dies you can chage it without having to drop the tank. I am just getting set to do the same swap and plan on a frame mounted pump. This way I can carry a spare for a trail fix. JMHO
Jim F.

[SamFromCO]

Hey Chris, I saw your post on CO4X4. I thought that your tank was already spoken for. I have a sender/pump mount that might work. I'll get in touch with you.
Jim, the reason that I want an in-tank pump is that I think that they have better pressure and less vapor locking problems. I believe that there is a reason that auto manufacturers put the pump in the tank. I usually carry along an external pump that I can stick in if it should break on the trail.

[code5337]

Sam,
I just got a email from him this morning, and he said he wants it. However, no money has exchanged hands. If he falls through, I'll email you and let you know it is available.

KOJ,
Chris O.

[jjunior887]

How do you plan on getting the fuel gauge to work with the newer sender, I thought the new sender sent the signal to the PCM and was sent to the gauge from there on the newer ones (the ones with the single wire gauge cluster at least). I may be talking apples to oranges here since mine is going to be a 98 with the OBDII. I'm interested because I'm getting ready to do the swap and I was just planning on the external pump and regulator so I could keep my stock sender to allow the gauge to work. -James

[SamFromCO]

jjunior887, I was under the impression that the '91-'95 used the same "type" of sender as the '88. I expected that if there were differences in voltages or things like that I would be able to replace the fuel gauge to remedy the problem. I don't think that they go through the computer on those years but I could be wrong. I would rather deal with that problem than the problems that the external pump has at higher altitudes.
Since you are using the external pump I'm guessing that your 4.0 has the regulator built into the fuel rail. When did Jeep switch to the regulator in the pump instead of on the fuel rail?

[Nsaltwater]

-=- originally posted by SamFromCO -=-
jjunior887, I was under the impression that the '91-'95 used the same "type" of sender as the '88. I expected that if there were differences in voltages or things like that I would be able to replace the fuel gauge to remedy the problem. I don't think that they go through the computer on those years but I could be wrong. I would rather deal with that problem than the problems that the external pump has at higher altitudes.
Since you are using the external pump I'm guessing that your 4.0 has the regulator built into the fuel rail. When did Jeep switch to the regulator in the pump instead of on the fuel rail?

Sam, I think I might have responded to you on another board but you are better off putting the fuel pump in the tank for just the reasons you stated. You can take the stock sending unit and graft a fuel pump to it. It's rather easy and the pump is like $60-70. I did that and have not had a problem with it.

OBD-II began in 1996 along with the relocation of the fuel regulator and I think was the same year the tank sending unit went to the PCM.

Check out cjoffroad.com (http://www.cjoffroad.com) for a board dedicated to 4.0L swaps.

good luck

[jjunior887]

Hey nsaltwater, you did what I would like to do but i wasn't sure it was possible so i had settled on an external pump. I have a 98 motor coming and it doesn't have the regulator on the rail like the 91-95 wranglers and older XJ's with HO. I was thinking of swapping in a fuel rail so i wouldn't ahve to use a regulator in line by the pump. Any chence you have a writeup of the in tank pump/older sending unit install? This sounds the best of both worlds. Do you still have the new sending unit hooked up too to keep the computer happy or did you just leave it out. I think i may need to hook up the new sending unit as well(even if it doesn't read right, i don't care) I just need the computer to see it so it doesn't throw a code for emissions reasons. I may be getting my hopes up here since mine is a OBDII and yours is a OBDI but it can't hurt to try.

[Nsaltwater]

jjunior887, I'm Scott DeLano, from cjoffroad. If you read my issue with the aftermarket fuel regulator, I'm going with a fuel tank switch. As the fuel pump is activated by the ASD, the fuel tank switch will be thrown to the side that is connected to the return line. When the fuel pump is shut down by the ASD, the switch will be thrown to the side that is connected to a blocked off port. This setup will keep the pressure in the fuel system between starts.

[jjunior887]

Ah i see, let us know how it comes out. I still havn't decided for sure what i'm going to do. I have a few weeks to figure it out so hopefully you'll have something worked out by then. -James

[SamFromCO]

-=- originally posted by Nsaltwater -=-
...you are better off putting the fuel pump in the tank for just the reasons you stated. You can take the stock sending unit and graft a fuel pump to it. It's rather easy and the pump is like $60-70.
Check out cjoffroad.com (http://www.cjoffroad.com) for a board dedicated to 4.0L swaps.
Thanks Scott. I modified my stock sender unit and mounted a '95 YJ 4.0 fuel pump in the tank of my CJ when I did the Mopar MPI kit. I haven't had the problems that I lot of people have had with the conversion like pinging and vapor locking. That's what made me want to do the same thing on my sons YJ 4.0 swap. Also, thanks for the cjoffroad link. I'm sure that I'll be spending some time there.