Well, I got my first problem.

So as you all know I just "bought" a 1974 Cj5 Jeep. Well I guess when I said bought I jumped the gun a little bit becuase what I actually meant was gave a small down payment until I got the rest of the money.

Well I went to go and pick her up today and pay the rest of the cash and I brought my girlfiends father so he could give the "Yes" or "No" on the purchase. He was an airplane mechanic for many years and his first job was in an auto shop. He owns an 87 Porsche and for as long as I have known him he has never taken a car to an auto shop becuase he does all his own work.

He took it for a 10 min drive, came back and said "as soon as I shift into 2nd gear the engine bogs down, dies, then comes back to life and keeps going".

What is happening is the transmission shifts into 2nd gear perfectly but what happens is as soon as you give the engine gas after going into second it bogs down and dies, then comes back to life and keeps going. The jeep runs perfectly in 1st gear and in 3rd, this only happens in 2nd gear.

He told me that it was either a fuel pump problem (mechanical pump in the jeep) or the after market EI Fuel Injection system was not working properly.

Please what could be the problem????? This will make or break the purchase and I really want this Jeep!

 

It might have something to do with the fact that a fuel injection system needs an ELECTRIC fuel pump to provide the pressure necessary to get the nozzles to spray the gas(in the 14psi to 34psi range).

If it just has the mechanical fuel pump, that won't work. Easy to just add an electric, though.

If the mechanical is inline with the electric, which is what it looks like from your previous pics, that will cause your problem.

You will just have to cut the mech pump out of the loop and just run the fuel line from the electric pump(in the tank? or mounted on the framrail somewhere) to the throttlebody.
Later you can remove the mech pump and cover up the hole with a "fuel pump block-off plate".

 

That makes alot of sense actually!

I might be mistaken but Im sure its a mechanical fuel pump, I belive this is a picture of it, am I right in thinking its a mechanical one? or is it electric? If its electric what could be the problem then?





Also if I need to replace my fuel injection how easy is it to simply put a carborator back into the engine?

 

That is a mechanical fuel pump. What is between the fuel pump and the carburetor? Did you get a picture of the fuel path from the fuel pump to the carburetor, and with the air cleaner off? If you have a throttle body injection system, you likely want to keep it and fix what's wrong with it rather than downgrade to a carburetors. Fuel injection is vastly superior to a carburetor, especially for a Jeep.

Ok, from those pictures, it looks like the fuel hose curves up over the top of the engine and goes to the throttle body. It's true that a mechanical fuel pump will not deliver enough pressure for fuel injection.

 

These and the other pictures are the only ones I have of the Jeep and its Engine. When I went to go and buy it today I didnt think to bring a camera as I didnt think there would be a need to do so (wont do that again lol)

Ok so the first thing that needs to be sorted out then is the installment of an Electrical Fuel pump. I have been looking online for them since I got home I have found a few but honestly I have no idea which brand to buy or what to look for. All I know is that I need one for a 258 inline 6 engine.

 

I would love to study the fuel system but the problem is that the vehicle is a good two hour drive from where I live. So unfortunetly these pictures and what I have seen in person are all I have to go on.

I guess it has a Howell TBI Fuel injection system installed, so the fuel pump I buy has to be able to work with this system.

 

Are you sure there is not already a pump installed somewhere between the tank and mech. pump?
I've installed a Howell system and they are supplied with an electric pump.

Also, does it turn over a bunch of times before it fires? Or does it turn say maybe once or twice and fires? I would think if the fuel is supplied by mechanical pump only it would take a bit of cranking to start.

 

She starts on the very first try every time

 

Can't do that. Too much pressure for the mechanical pump. Or maybe they did it and haven't burst the mechanical pump or blown the hoses and clamps yet.

To the OP, man I think you're just going to have to fish or cut bait. There's only so much you can learn about a used car without owning it. And people always sell cars for a reason ... so you have to expect some setbacks once you finally own the car.

 

The Howell stuff is just repurposed GM TBI. They assemble the parts into a kit, provide instructions, and provide an ECU with a custom EPROM.

If GM TBI uses 12 psi, then that's what the Howell kit will use. They supply a remote mounted fuel pump which can be seen in a picture here. http://www.howellefi.com/customer/tbi-kit-1972-80-cj-4.2l-offroad-emissions-legal.html

The mechanical pump is supposed to deliver 5-7 psi, so the throttle body might run on that ... don't know. You are supposed to use special hoses and clamps with the TBI pressure, so I presume the typical breeze clamps on a barbless nipple would blow off at 12 psi ... maybe not.

 

I have to say that I agree, however even at the age of 21 the parents need to be convinced of it as well.

However after some more research as well as what has been said on here I honestly belive that it will be a simple fix such as installing an electric fuel pump.

I plan to grab a trailer and get her home next weekend and install the new fuel pump.

 

Bingo-Bango!!!

Now you're talkin'

 

Now that I think about it when the Jeep was running at idle it sounded a bit like it was misfiring. The lack of the proper ammount of fuel being sent to the engine would cause this as well as the poor performance in 2nd gear.

So here is what I have installed on my engine

http://www.howellefi.com/customer/tbi-kit-1972-80-cj-4.2l-offroad-emissions-legal.html

I am having a hard time finding a retailer that sells the correct type of fuel pump I need for this system. I only know of a couple web sites that sell jeep specific parts and Im not finding electric fuel pumps in thier inventory.

I would be most appreaciative if you guys could point me in the direction that you would personally go for getting parts such as this.

 

I found where they mention the fuel pressure needed.
Page 3 of this.
http://www.howellefi.com/skin1/pages/US/4_barrel.pdf

It takes the same as later jeeps with TBI.
The "low" pressure fuel pumps(13-15psi) seem to be for the throttle body injection.

Find an inline electric pump in that psi range or, if you feel froggy, adapt a newer jeep in-tank unit from like a 90 YJ with the 2.5L (TBI)(14psi)

http://www.inlinefuelpumps.com/

http://www.autoperformanceengineering.com/

http://www.holley.com/12-927.asp

 

I decided to actually call Howell and talk with them about thier system. They were very nice and I explained my situation and the guy on the other end was shocked to hear that the Jeep even ran at all on a mechanical fuel pump with the trottle body conversion kit.

He told me to grab the electric fuel pump they sell and put that on the jeep. He said that would be the first and nessecary step in figuring out what is wrong and if that does not work to give them a call back.

I like these people and they seem willing to help even if your not the person who bought the system.

 

ITS DONE!!!! I got the part ordered and Im picking her up on Thursday.

Final price paid...... only $3,000!!!!!!!