Rollover 4.0 litre startup advice needed

Hey!

So I know this is an XJ forum, Yes I own an XJ Yes I love them etc...now that that's out of the way,we're talking TJ here....specifically a 97 4.0 SE TJ w/ 110K km on it.....

but it's the same 4.0 obd2 engine were talkin here....

also it's probably been sitting parked for 6 months.

So I picked up a Jeep (the 97 TJ, rollover damage, from auction) as a engine donor for my other TJ with a shot 4-banger.

Although I've heard that doing a 4.0 swap is very involved and a waste of time, I'm doing it anyway...I'm hoping that the fact that they are both 97 TJs and that I have all of the wiring, fuse panels, dash etc etc.... should make it more plug and play even if it is involved....

So obviously I want to start up and hear my donor engine run...I tried to fire it up today...it would not start. Before attempting I removed plugs and cranked to clear oil. none came out. No I did not mix up the wires and yes I checked rhe book, they are corectly oriented. It turns over and sounds like it wants to start but also makes popping (loud) explosive sounds from the intake....I actually blew up the air box!!!

I suspect timing but don't understand how it could have moved during the crash.

The Jeep appears (fom my CSI investgation) to have locked up a front tire completely (for unknown reasons) and skidded until the tire blew (yeah, seriously) at which point it struck something with the same front tire, and then rolled over. There was no "impact" (except with the ground), the body panels are damaged from the roll cage bending from it rolling, but is not smashed.With the exception of the rad (cracked) and the airbox (blown up) there is no underhood damage.

Why won't it start?? Any ideas would be appreciated...timing is one of the first things I want to check, but it seems like a bit of a hassle and kinda unlikely to be the problem.

Maybe the cat is clogged from all the oil/?


:compwork: thanx

interesting...not sure, I wanna know too

and, the swap will be involved but fairly uncomplicated since you have all the parts.

check the frame on the rollover one...if it's OK you're gonna be easier to swap your nice body onto the rollover frame, and just leave the motor and everything intact on the rollover

yeah that's an idea but I'm not sure it would be much easier..thanks, though.

The rollover frame is tweaked very slightly....but the other one is cherry and my baby...I'm pretty sold on just doing the engine and peripherals...


:wierd:

As long as it wasn't hydrolocked, or anything like that; I'd probably just pull all six plugs, crank it for a few seconds, and make sure no-thing squirts out the holes. Put the plugs back, and start it up.

The only thing you might need to do is make sure there's no oil that dripped past the rings and loaded the chambers up - which is why you're cranking without plugs. Problem solved.

Mine smoked a lot for a minute or two after rollover and ran fine.

5-90 said:

As long as it wasn't hydrolocked, or anything like that; I'd probably just pull all six plugs, crank it for a few seconds, and make sure no-thing squirts out the holes. Put the plugs back, and start it up.

The only thing you might need to do is make sure there's no oil that dripped past the rings and loaded the chambers up - which is why you're cranking without plugs. Problem solved.

Click to expand...

Hey man thanks for chiming in...you always seem to have a vast wealth of useful info, so i'm glad to have got your attention!!

So I pulled the plugs and cranked...no oil...I don't know if buddy (prev own) tried to start it after rolling or not...hopefully he didn't damage it too badly....

The problem now is it WON'T start...and is making weird implosion pops and bangs....these are not mechanial sounds (metal),they sound like ???? maybe incorrect valving, timing??? How would these be affected by a rollover?

Sunday is start it day so I am looking for as many possibilities as posibble to possibly consider.

Thans for the advice, guys!!:cheers:

Timing chain jump a tooth or two at impact?

CPS/Flywheel/flexplate alignment affected at impact?

If CPS makes contact for even 2 or 3 revolutions it's bad...

Timing chain=maybe...this is high on the list of things tocheck

When the CPS fails, there is no spark and no cranking, right??

it cranks.

THX

I would suspect the dist cap. It could be
1) cracked
2) loose
3) water from busted rad

After that check the timming chain.

Your motor will turn over with a bad CPS... ( I call that cranking...) it may even try to fire up a little if the CPS initially puts out a burst of pulses to the PCM....but usually you won't get enough good signal to get a continuous quality spark, to get you started and keep it running...

A compression test might be in order to rule out internal damage.

I don't mean to be a dick, but double and triple check your plug wires. workin at a dealership that's what sound like is happening.

Remember that the firing order is on the intake manifold. Also pull the distributor cap when it is on TDC and make sure the last yo yo didn't put the distributor in wrong and compensate by shifting the wires.

Good Luck.

Been sitting for 6 months ? Does it even have good gas in it ? the gas over the last 5-8 years does not have the preservatives in the older gas had and seems to sour after 5 or so months. Might have to clean the injectors too if they were really crudded up from any oil that was in the cylinders after it rolled. My sons TJ fired right up after a roll over and we spent about 3 months replacing body parts.

Thanks to all for your insights and ideas!!

hopefully It starts on sun. w/otoo much trouble, but I definately have some new possibilities to consider.

Thanks again...keep it comin'

Rcnerd

I would do a compression test on each cylinder.

Pretty sure 97 have a rollover safety cutoff switch, it has manual reset button.
I think it's somewhere around the driver side kick panel.
Little black box with a button sticking out.

langer1 said:

Pretty sure 97 have a rollover safety cutoff switch, it has manual reset button.
I think it's somewhere around the driver side kick panel.
Little black box with a button sticking out.

Click to expand...

ok, just in case you didn't realize, this is a tj

Can anyone confirm this? I've never heard of such a thing.....

codyj86 said:

I don't mean to be a dick, but double and triple check your plug wires. workin at a dealership that's what sound like is happening.

Click to expand...

Agreed. At TDC on compression stroke the trailing edge of the rotor should be just past the #1 post on the cap.

old_man said:

A compression test might be in order to rule out internal damage.

Click to expand...

unfortuneately for me, the old man was right!

UPDATE:

So sunday kinda sucked..couldn't get it to start, but did find the problem
the engine had a stuck valve which was causing fuel to ignite inside the intake manifold

hopefully this is the extent of the damage.

tomorrow is new valve time wish me luck!!