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post #1 of (permalink) Old 12-03-2002, 06:43 PM
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help me keep my jeep

I have an 89 yj with a 4.2 that is shot (110k miles). I have limited technical knowledge and neee advice on getting a new engine. I am a college student with very limited funds.
My three options are buy a rebuilt 4.2, find a salvage yard 4.0, or get $3000 for the rig at a push/pull/drag sale.
I would prefer to put in a 4.0 over the carborated 4.2 but will just any 4.0 from the junk yard bolt up to my automatic tranny or do I need adapters? Any other advice for the swap?

Thanks in advance for any help. [email protected]
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post #2 of (permalink) Old 12-03-2002, 06:56 PM
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Re: help me keep my jeep

Although not a TOUGH swap (by swap standards) the 4.0 does require a bit of technical/electrical knowledge or at least some help, time, and a place to work on it for a while. You would be best off going this route, getting a running 4.0 from a later model YJ , the underhood wiring harness, the computer and computer wiring harness, and all related peripherals bolted to the motor. You will need a wiring schematic for both YOUR YJ and the Wrangler that the engine came out of so you can match up wiring...I don't think it is "Plug and Play". You will be much happier with the fuel injection and the 4.0 is a screamer of a motor.

The rebuilt 4.2 would be the easiest swap but probably a wash, money wise compared to the 4.0 (if you are using a used 4.0 and equiptment).

Trading the Jeep in is only an option if you are worried about dumping too much into a new motor or a swap, but keep in mind. The dealers that run push-pull-drag sales, usually have their vehicles marked up a couple grand above what they are really worth, so you really save nothing by doing this. You have just given your Jeep away to someone who won't appreciate it.

I say go for the 4.0 swap. You WILL have fun (keep telling yourself that during the proscess [img]images/graemlins/crazy.gif[/img]), you WILL learn alot about your Jeep, and you WILL come away with a better understanding of how things work.
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post #3 of (permalink) Old 12-04-2002, 03:28 PM
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Re: help me keep my jeep

what the heck is a push/pull/drag sale? Im clueless. Thanks.
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post #4 of (permalink) Old 12-04-2002, 04:09 PM
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Re: help me keep my jeep

</font><blockquote><font class="small">In reply to:</font><hr />
what the heck is a push/pull/drag sale?

[/ QUOTE ]

You got to be kidding me. You never heard a car stealership advertise "We'll give you $2,500.00 trade in for anything you can push, pull or drag onto our lot" ? [img]images/graemlins/grin.gif[/img]
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post #5 of (permalink) Old 12-04-2002, 04:30 PM
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Re: help me keep my jeep

What exactlly do you mean by "shot". Since Im guessing what you mean by "shot" Id guess maybe it needs new rings or the head reworked. It isn't as hard as you may think to do a cheap rebuild, You could probablly rebuild the basics for around 200-300 bucks and save your Jeep and the stealership ain't really given ya 3000.00$$. Since your in college you must be reasonabbly intellegent and with a minimal mechanical ability you should be able to do what ever needs done. If your not sure whats really wrong you could take it around to at least 2or3 repair shops to find out what it would take to fix it. Good Luck (anything mechanical is rebuildable or fixable)
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post #6 of (permalink) Old 12-04-2002, 04:56 PM
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Re: help me keep my jeep

I've been told by several locals that I can not put a 4.0 in my jeep. They mentioned something about a throttle position sensor as well as a flywheel conflict. I realize the fuel injected 4.0 will have some extra hardare but shouldn't it bolt to my tranny? Do I need a 4.0 from any specific model or year of jeep? Can anyone give me specifics as to what major conflicts I will encounter with this swap? What is a reasonable price for a salvage yard 4.0?
Once again, thanks in advance
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post #7 of (permalink) Old 12-04-2002, 07:31 PM
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Re: help me keep my jeep

the biggest obstical is the crank positioning sensor (CPS) the 4.0 has a ring on the flywheel and a sensor on the bellhousing for the CPS. your bellhousing will not have the hole in it for this. HESCO sells a kit to relocate the CPS useing a special harmonic balancer thats not at all hard to install. it is almost $300 though. i have heard that some places will drill the hole into your bellhousing for the sensor fo a nominal fee, but the hole needs to be in exactly the right place. the opther obstical you'll run into is the fuel pump.. the fuel injection will require an electric fuel pump and pressure regulator. this is not an uncommon swap, but you really need to do your homework to get it right and not have any surprises. do a search on this forum about the stroker engines... i realluy really like mine and you have most of the parts you'd need already.
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post #8 of (permalink) Old 12-04-2002, 08:07 PM
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Re: help me keep my jeep

I'm wondering like pig what you mean by shot is it a mechanical failure? With todays modern engines 110k is usually just broken in unless they get complete lack of matanince. You'd be amazed at what a complete tune-up and a few adjustments can do.

About 4 years ago I picked up a 88 Bonneville with 125k from a junk yard for $400 that the prev. owner said was shot. It even turned out to be a sons car of one of our customers at work. All I did was give it a tune-up, trans service and new rubber and some of the normal wear stuff through the years like brakes just a liitle TLC basicly nothing major. Well today it has 225k and still running strong and I still drive it 100 miles a day and the a/c even still works! Not bad for a shot car I figure and every time I see the customer I tell him his sons shot car is still running and he just shackes his head and tells me to shut up.
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