ok so I just bought a "new" re-built engine from advanced auto and installed it ( jeep was running when I tore the old motor out )the new engine has compression , fuel, and spark, I turn it over my oil pressure goes up it studders every once in awhile gives a random back fire but just wont start, its a 92 2dr sport 4.0HO I6. I know this is a long shot im just hopping for some suggestions because I have tried everything I can think of

 

ok so the original post was kinda vague so here are some more details. purchased the "new" rebuilt engine I also purchased and installed new the cluch,fly wheel, presure plate, distributer cap and rotor , ignition coil, plugs and wires, and radiator. everything elts was the original stuff off the old engine THAT WAS RUNNING when I parked it ( 300,000 miles blown head gasket, burnt rings and MASIVE BLOW BYE was the reason for the swap ) I have checked all the wire harnesses and sensors. there is plenty of compression, the spark is great and its getting fuel, the part that is really confusing me is that all it does is sputter and a random back fire every so often EVEN WHEN GIVING IT STARTING FLUID !!!! hope this helps drum up some ideas thanks guys

 

Are you sure distributor was correctly installed?

 

Yeah, your timings off. You're either one tooth off or you've got some plug wire(s) in the wrong place.

 

https://www.google.com/search?q=how+...en-US:official

 

hey thanks for the suggestions, I am looking into the distributor settings now, I did that lastnight and I started to get more backfiring so im thinking I am getting closer to whare it needs to be, if anyone has any more ideas I sure could use them hahahaha thanks for all the help I will try agin and see how it goes

 

ok so I have done everything to the timming ( adjusted the distributer as the book said to ) that I can and I feel its correct so are there anymore ideas out there in XJ land for me because still wont start just sputters and backfires every once in awhile

 

Setting Your 4.0 at #1 TDC


With #1 spark plug removed, turn the engine over clockwise using the 3/4" front crankshaft bolt. You will see the degree marks on your front cover. Mark the 0 with chalk or white-out.You will see the timing mark on the balancer. Mark it with chalk or white-out. While turning the engine over, put your finger/thumb over #1 spark plug hole. As the mark on the balancer approaches the marks on the front cover, if you are coming up on #1 TDC, pressure in the cylinder will push on your finger. If there's no pressure, you're at #6 TDC and need to crank the engine over until you see the marks coming together and you get pressure. Set the mark on the balancer to the 0 mark on the front cover.
http://www.angelfire.com/my/fan/dist_index.html

 

hey, thanks cruiser !!!! I will be doing that today, it makes sense, I was thinking while aligning my timming marks " how is this possible that every time these marks line up its TDC on the #1 ? " thanks again cruiser I will post results later

 

Do you have the Field Service Manual (FSM) for your Jeep? I just replaced the coil, cap, rotor, wires, and plugs on my '97 and had a similar problem.

Well, actually, my son did it. He got the plug wires in the wrong places. He had the ORDER correct, but he started in the wrong place. Worse, I found TWO diagrams online that were WRONG. One on Advance Auto's site, and I forget where the other was.

Then I remembered my PDF manual. Looked it up, and sure enough, the online diagrams are wrong. Re-wired it according to my FSM, and bingo, it fired right up.

Check the plug wires!

QUESTION: Can I post an image of my manual to help him out or am I going to get whacked for copyright violation?

Well, here's one way to find out:


By the way, this is actually from a '94 manual, but it worked fine for my '97. I can't imagine it changed over the years, except perhaps for the Renix Jeeps. It's a pretty basic item. Maybe someone who knows can chime in on that point.

 

HEY! That's the first diagram with the correct #1 location, (at 5:00 viewed from the side) I've seen for a 4.0! Yea Mark, not his fault, most stuff has #1 in the wrong place. Renix is the same as the newer Btw.

Also make sure your MAP tube is in and good. It might be flooded with a problem there.>>

There is a brittle little tube. It comes out of a rubber plug, low on the engine side of the throttle body. It runs back to the firewall, then up to your MAP sensor sort of high up there near center on the firewall. CRUCIAL!! The MAP will tell the ECU to dump fuel with less/no vacuum. Any crack or blockage and it will be pig-rich. (black smoke, fouled black plugs). You can pull the line off the MAP and feel for vacuum with your finger. If it runs!

 

Gonna hafta ban your sorry ***!!!

LOL.

Thanks, Mark.

 

Really! Well, then, I'm thinking this diagram ought to be in a sticky somewhere.

Who knows how many hours of frustration have been caused by wrong diagrams!


BTW, yeah, it was his fault. He had a working engine to work from. All he had to do was to copy it.

But then, this is the guy who emphatically does NOT want to be a mechanic. (Though he did a good job replacing brake shoes today.) His older brother would have gotten it right.

No problem. We have him scheduled for a flogging at oh dark thirty. THEN all will be forgiven.

 

That's why I have it in my signature. I put it there last year and have no plan to change it. Hey now....NOT following the manual would be a mistake, (most of the time). He was tricked.