Timinng Chain Jump - I think

I read thru OldMan's FAQ on a no start, but not quite the same

The jeep just stalled on me after exiting the HW, I was sitting at idle waiting to pull into traffic, gave he soem gas, and stalled, no restart.

Ok guys - I think this is my issue, my neighbor is out of town and he borrowed my timming gun, so I am not sure yet. Tell me what you think.

I have spark, and fuel in the rail, she turns over without an issue.
kind of sputters without starting.
The CPS checks out good

BTW I would love to meet the engineer who put the timing lock down bolt ina nice position where youcan not get a socket on it, and a wrench is blocked by the motor mounts. What an idiot.
I need a 13mm crows foot to get that loose of couse I don't have one.

1) what do you all think? Timing chain?
2) How tough a job is this?
3) does the engine need to come out to replace it?
and here is the nice question...

4) what perfromance upgrade would you do while putting in a new chain?

Of course that is assuming that the valve train has not been destroyed by a jumped chain.

Thanks

Before you do too much work, Grab a cheap set of Champion spark plugs and replace yours. I have seen so many engines not start due to wet fouling that I have lost count.

Odds say you lost your CPS at least long enough to wet foul the plugs. A jumped timing chain is extremely rare. A quick check is to crank the engine over to about 15 degrees before TDC then pull the distributor cap. The rotor should either be pointing at cylinder #1's post or exactly 180 degrees out.

plugs wire, rotor cap are 1000 miles old.
I also pulled all the plugs and cleaned and re-gaped them.

I will pick up some champions later today, and try them. I am and have been running bosch platinums for years, as I have a MSD 6AI, it tends to erode champions real fast.

I will test for the TDC and cyl #1.

I found the cause for the stall was a broken wire leaning to the coil, I have repaired that, still no start.

I tested the CPS it's good, and it is only 8000 miles old, replaced it with the new clutch.
Thanks

If you're referring to the bolt on the distributor , the timing is not adjustable.

How did you check for fuel pressure? Did you use a gauge or just press the valve?

Saudade

I had a fuel pump issue two months ago, new fuel pump installed, 30 PSI with FPR under vacuum, and 39 psi without vacuum.

While cranking I have @ 28psi.

how many miles on the odometer?

About 13 years ago I had a buick with the olds 403 that the timing chain jump on the cam gear. It sputtered and stalled in the middle of the intersection at 59 Ave. and McDowell Rd. in Phoenix,AZ. A lot unhappy drivers that morning.

She only has 145,000 on her, and I take great care of her, in fact this is the first real issues I have had.
I have owned her since 1995.
Talk about treating her right, the original clutch lasted till 137,000

If that is the original chain, it's past due for replacement.
My gave out at 67,000

cf_collins

What is the recomended interval?
I guess I'll put one in, just not sure if that is my problem.
I'll get my timing gun back tomorrow and check the actually timing?
What is the actual timing supposed to be, I have a haynes manual, but they pretty much suck.

If my timing is not slipped, and I have fuel, spark, and still no start.

I guess I need to see if my injectors are actually squirting fuel

I am kind of lost here, and am needing help, as this jeep needs to get inspected by end of December.

I don't want to just throw parts at it.

OLD_MAN - Where can I gets a NOIDS lamp set? Can i rent one?

Actually would an O-Scope with an inductive pickup work? I think it would.

I've never seen a chain rated more than 120,000. Check your owners manual. I'm in Iraq, so I'm unable to look at mine.
NOIDS lamps are pretty cheap.

I haven't bothered to try a search yet but I am curious what the typical average life of the timing chain is for the 4.0. The chain on my 85 2.5 failed at ~270,000 miles.

I have not seen a 4.0 with a timing chain related problem. The chain on my 4.0 lasted through a hydrolocking (replaced it on rebuild anyway). And my first motor went 250k on the chain, no noticeable difference between it and a new one. I would not worry about changing the chain unless you want to AND it is out of timing. Not a cool job, especially with the motor in the truck.

Noid lights are like $20 a set at Advance Auto, might be cheeper actually.