I have a 2003 6.0 in my 1979 CJ5. I have close to 3000 miles on it. Four times in the past month or so it failed to start. What happens is the fuel pump doesn't power up when the key is turned. If I turn the key on and off a couple of times it will eventually power up and start fine. It has never died once it is started and it has done it cold and hot. I checked my wires and all seem ok. Would a relay act this way or is it more likely the computer?

Thanks

 

It could be the relay, however I'd find the hot power wire coming off the computer if you can and test that. Maybe even wire a simple test light bulb from Radio Shack into the circuit so you next time it acts up, you'll be able to see whether or not the computer is supplying power to the relay.

By the way, how did your conversion turn out?

 

Hi Fastkat! Other than this minor issue, it turned out great! I could not possibly be happier with it. I'll have to get my camera out and send a couple of pics to you. It purrs like a kitten and runs HARD when I stand on it. There was a car club that was putting on a small car show at the local autozone. I stopped in for some power steering fluid and when I lifted the hood to top it off, I had an instant crowd around the Jeep. It was kinda' cool.

How's the Jag/LS1 project going?

 

Fastkat, now that you mention it, I think I'll put a test light in the Jeep 'cause the wires to the relay are easy to get to. I can narrow it down that way. Great advice! Don't know why I didn't think of that, but that's what this forum is for

Thanks

 

I had the same problem too. My problem was the grounding for the fuel pump relay. My ground wiring was all good also but it seemed it had to have the correct ground that was part of the original harness. My CJ7 also runs unreal, we love it!
Thanks

 

How did you end up grounding it?

Thanks

 

Not so sure it is my fuel pump now. Just happened again andI could hear the pump pressure up with no start. No tools with me, so I could not do much. Finally started like normal after trying several times.

Any Ideas?

 

Hey Aaron,

I haven't had much time to work on my LS1 Jag lately... I have been accumulating parts over the summer and am now trying to set aside some time to dig into it again.

I'm glad your install turned out well! Definitely post some pictures up! As far as the starting problem goes... I am not sure. Is this only on hot starts? Is it just cranking and not firing at all? My next suggestion would be to put it on an engine diagnostic computer and see if it's pulling any trouble codes... but I'm not sure how you'd go about that without the data port.

-Dave

 

Hello fellow jeepers i'am new to this site . My project is a 1986 cj7 putting 5.3 , 4l60e from 2002 truck . Just mounted motor in yesterday waiting for advance adaptors for transfer case adaptor. I mounted org. fuel pump and bucket into my new tank. Sent the wiring and computer to spear tech. Have not received them back yet. Any major problems you guys run into ? Also just purchased alum. 2 core radiator with electric fan. Have built two other jeeps with old school carbs. frist time with high tech fuel injection.

 

Which headers did you guys use when converting to narrow frame CJ:s?

I am putting a 5.3 in my CJ-7 this week and am wondering whether the truck manifolds fit or not?

 

It was grounded thru the relay on the fuse block to ground on the engine block when problems started. I then grounded it thru the relay on the fuse block to the original grounds on the harness. It's been starting with no problems ever since the original grounds to the relay were reconnected.
Thanks

 

Check out my thread: "Cj7 Finally On It's Way" it sounds like you are on the right track. Good luck, it's fun.
Thanks

 

IMO it depends on which transmission you are going to use. Clearances are tight on the drivers side with the 4L60E. Did some research and got some possible better headers for the clearance then what I got (Hooker Block Huggers). In my swap the truck manifolds pointed straight to the frame. Now knowing what it takes I plan to mod the steering rod for more clearance. Check out my thread "Cj7 Finally On It's Way" my wife and the kids really enjoy it.
Thanks

 

What size are those Hooker Block headers..tube wise. Could you post a picture of them installed , showing the motormount clearance you have with them. Thanks.

 

It may be that I need the block huggers too then if the truck headers pointed to the frame.... Oh well, it does not matter anymore as quite much $$$ will be invested in it anyway

 

The block hugger headers i used are part # 2313HKR. No exhaust pipes run yet but looks like they will work. Just got my advance adaptor today installed not sure how the front drive shaft is going to fit ? When i hold it up there looks like it runs onto trans. pan. Did you guys run into this? thanks for your help. P.S. i'am running dana 300 t-case with 4L60e trans.

 

Humj7,

I have a 2 1/2 inch suspension lift which seems to help with clearance. The only issue I had with driveshaft clearance was the oil level sensor on the side of the pan. I trimmed the aluminum piece sticking out and replaced the sensor with a drain plug. For the exhaust, the truck manifolds also dumped on the framerail so I used 2002 F-Body manifolds and they worked perfectly. I ended up fabbing exhaust flanges for the manifolds though. I actually wanted to used manifolds because in my experience they seem to be much more resistant to exhaust leaks than headers...and cheaper too. Let's faced it, a 325 horsepower 6.0 liter in a CJ5 doesn't really need to benefit from the few ponies I might gain from headers. I will probably put on a different oil pan, probably F-body or C6 LS2. The truck pan hangs a little too far down for my tastes and with the Jeep almost any pan will work...probably even the winged one. My combo is 6.0/T18 four speed/Dana 20/4.10s/33s

Fastkat-One of the pics I sent you shows the drivers side exhaust manifold, can you post it-I don't know how.

Power on-did you do your harness or someone else-John Speartech did mine. I didn't have to do anything with grounds through the relay, just connect the labeled wires from John. I'm waiting to have the no start happen again so I can check for spark as I have a sneaky suspision I might be dealing with a suspect crank position sensor.

Truth is my swap went pretty smooth all things considered. Exhaust flanges was probably the most frustrating part for me. Even that wasn't that bad. $30 to the metal shop to cut them on a water jet and a couple of 12 packs to a friend at a machine shop to drill and tap holes.

Good luck

Aaron

 

Aaron,

The conversion looks great! How does that 6.0L run? It sounded great in the van but I never had a chance to take it out to see how it pulled.

Here's the pic...



Also, email me your email address. I tried to reply to your email and it didn't work.

-Dave

 

Dave it pulls real hard and sounds good. I have 2 1/2 inch duals with turbos. It's kinda funny when some little ricer tries to ace me out at a stoplight...well let's just say none have been able to yet. Thanks for posting the pic thought it might help others see how the manifold worked since the drivers side is the hard one.

My home address is hackman@frws.com

Daytime number is 719-365-1564

Thanks

 

Looks Unreal Aaron! I did the stock harness myself. It still has a lot of connectors which I will be eliminating as time goes by. Everything is wire loomed so it looks good as stock. In your pic I see the steering shaft is after market. Where's it from? As for me my header is bashed in a little to clear for the steering shaft. I am in the planning to 3 link my shaft real soon and fix my headers. I can't live with the bash header. I wish I went with 2 1/2 on each side also. You can see my 2 to 1 set up on my thread. I know it's holding back a little but still smokes the rubber at will! Put up more pic's, we got a good thing going.
Thanks