View Full Version : 4.0 head on 258
alrighty, got the Chero up and running last night.
At first she was running like crap then I found 2 plug wires that were not all the way connected. She ran a little better, I could at least get it up the hills.
But now I have either a knock or pinging when stepping on the gas or when going up hills, what can I do to stop this?
I slapped on a motorcraft 2100 2bbl carb, if this helps. I also have a hi pitched whistle when just starting to step on the gas or letting off of it, intake leak? vac leak??
Please help!!
NOI-54X
10-20-2003, 11:50 AM
Are you sure it's a 4.0 head ??? the 4.0 has diff. water ports and the intake chambers are diff. so it could be that your gasket/intake doesn't line up proper.Reason I haven't put 4.0 head on mine . I have been exploring TBI off chev that will bolt up with little adaptation.Good luck
no, it is a 4.0 head, I had the water ports welded up and i did a little grinding on my stock intake to make it work, I guess I will try and losen up the intake and move it a little to get rid of the whisle, its the dam pinging I don't like
hey 86, I looked at that too.
Now that I have a 4.0 head, all I need to do is find a good fuel injection. Can't use the stock 4.0 intake because I don't have enough room with my big brake booster and I want to keep my HEI dist, I also don't have the cash to get one of those Mopar kits but I have read that when you put the 4.0 head on the 259 and get fuel injection, its almost the same as making a 4.0 stroker engine.
NOI-54X
10-20-2003, 02:26 PM
Could it be outa time a little maybe spark knock???
Junkyard Jim
10-20-2003, 04:53 PM
You will get TONS of ping if you didn't do the "Nutter bypass" on your computer controlled carb wiring.
macguyver
10-20-2003, 06:25 PM
The 4.0 intake ports are much larger than the 258. the gasket covers them up but the intake manifold does not so it can suck air by the gasket. Check all around the manifold for leaks, you might have to remove the intake to see where the gasket is crushed to find the leaks.
Junkyard Jim
10-20-2003, 07:51 PM
It depends what year the 4.0L head is as to the size of the ports. I would switch to Hydroboost and use the Renix or HO intake with a carb adapted to it. (or Renix with an XJ booster. Kev can have the one I modded, but I can't guarantee how well it will work!)
Jeepmauler
10-21-2003, 05:29 PM
I've got a complete 4.0L head,intake manifold,injection and harness.It has new injectors and is complete off a running '90 XJ.
Hey JIm, I never had the computer controlled carb. The carter I took off never had that stepper mtr. I might take you up on the intake. Now, what the heck is hydra boost brakes??
Junkyard Jim
10-22-2003, 07:03 AM
Hydroboost runs off the power steering. Another possibility is a Dodge van 90 degree brake booster (I tried posting a pic, but I get "out of memory" error? weird!
Hey Jim
I found a few of those Doge Van 90* boosters, how the heck will that help me put on fuel injection?? Looks like it would make the booster even more in the way.
I did find a 70's type wag with a littler booster, its mounted with a bracket that actually drops it down about 2" lower.
Junkyard Jim
10-27-2003, 06:41 AM
Originally posted by Zorm
Hey Jim
I found a few of those Doge Van 90* boosters, how the heck will that help me put on fuel injection?? Looks like it would make the booster even more in the way.
I did find a 70's type wag with a littler booster, its mounted with a bracket that actually drops it down about 2" lower.
A: You want to go up, not down! If you reverse the Dodge van booster bracket, it should swing away from the intake (but I didn't measure to see the difference yet. I'll check it out on the '83 Cherokee since it has a 6 cyl)
hey Jim,
still back home in Pensacola. I think I found the front spindles that I need to convert the D44 to an 8 lug, they arew on a 70's Chevy 10 bolt, and have something like "Auto Lock" hubs? just need to talk down on the price.
Now about this intake. You modified it for what?? do you think I could get the motorcraft 2100 carb on it? and, would a brake booster from a XJ bolt right into our FSJ?? That would take care of the space thing.
Junkyard Jim
10-29-2003, 08:36 PM
Originally posted by Zorm
hey Jim,
still back home in Pensacola. I think I found the front spindles that I need to convert the D44 to an 8 lug, they arew on a 70's Chevy 10 bolt, and have something like "Auto Lock" hubs? just need to talk down on the price.
Now about this intake. You modified it for what?? do you think I could get the motorcraft 2100 carb on it? and, would a brake booster from a XJ bolt right into our FSJ?? That would take care of the space thing.
Autolock means no adjustments! <G> (always engaged) On the intake, I just cut a piece of the throttle linkage bracket to clear the XJ brake booster. The XJ booster required a different fitting to hook up the lines and I had it bolted on, but I don't know how much pressure it would give.
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