jeep help!!!!!!!!!

[trxguy]

my buddy has a 89 jeep comanchee with a 2.5L 4cyl it all of a sudden stopped running the engine cranks but does not fire.. he noticed that the timing had jumped so he replaced the timing chain..and the crank shaft position sensor.. we have spark fuel and air but it will not fire. does anyone have any ideas as to what might be going on??????????

 

[boxboy]

how does a chain jump timing? and how do you just notice it?


Do you have compression? and are you sure you re-timed it correctly?

 

[trxguy]

scott,
there is over 100k on the engine... i believe he turned it over by hand and the timing marks didn't line up...i wasn't there when he did it...but thats what he told me; that it was off a couple teeth..i asked him also about compression he said he has compression... not sure if he is planning on doing a compression check, we did talk about it earlier.....

 

[Binder]

Is it a interferance engine?

 

[TreeClimber]

how does a chain jump timing? and how do you just notice it?
Do you have compression? and are you sure you re-timed it correctly?

The teeth wear down, and the chain stretches. When that happens, the chain can jump a tooth or two. When my AMC 304 jumped, it would barely run at low RPMs, but ran great if you could get it to higher RPMs. I drove home in low range at 4000+ rpm, before I tore it apart.

Is it a interferance engine?

As far as I know, Jeeps aren't interferance engines.

I'm wondering if he installed the distributor 180*

 

[trxguy]

The teeth wear down, and the chain stretches. When that happens, the chain can jump a tooth or two. When my AMC 304 jumped, it would barely run at low RPMs, but ran great if you could get it to higher RPMs. I drove home in low range at 4000+ rpm, before I tore it apart.


As far as I know, Jeeps aren't interferance engines.

I'm wondering if he installed the distributor 180*

no everything was done in steps the chain was done first... then someone mentioned sensor...distrib went in the same way it came out everything lined up the way it was before when it ran...
when the engine is on top dead center of the compression stroke the rotor points to the number 1 firing position.

 

[Flat-Bed_3rd_Gen]

is this a throttle body injected 2.5? where do you have fuel? in the lines? is the injector firing?

 

[trxguy]

is this a throttle body injected 2.5? where do you have fuel? in the lines? is the injector firing?

TBI fuel is there...he has also tried spraying starter fluid directly in and nothing

 

[crash2]

So lets start with the basics.

#1 verify the engine has compression and internal timing is correct (always verify mechanical)

#2 verify spark/injector pulse

#3 verify pump operation/pressure

There are other aspects to why it might not run--but always start with the basics first.

 

[Binder]

My guess (and guesses aren't worth much)......The timing chain is in wrong.....If it was loose enough that it could have jumped time and he looked at it and it was 2 teeth off.....There would have to be much slack on one side of the chain while the other side is tight. When he looked at it probably the wrong side was tight.
Do a compression test, I bet it's way low on all cylinders....:corn:

 

[Travis1]

When swapping timing chains you are supposed to line up the marks, and if it skipped a link due to wear, one would hope he swapped the gears too.

ok, so the distributor went in in the same position.

But was the rotor in the same position inside the distributor.

 

[Binder]

When swapping timing chains you are supposed to line up the marks, and if it skipped a link due to wear, one would hope he swapped the gears too.

The way I read it he didn't replace the chain or gears just moved them.....

:Edit: Yeah it says in the firs post he replaced the chain. :Edit:

 

[trxguy]

When swapping timing chains you are supposed to line up the marks, and if it skipped a link due to wear, one would hope he swapped the gears too.

ok, so the distributor went in in the same position.

But was the rotor in the same position inside the distributor.

yes gears and chain...i am told yes to distributor and rotor position

 

[zukkev]

Definitely sounds a lot like timing was not set properly...does it backfire, or do anything at all like it's trying to fire???

 

[trxguy]

My guess (and guesses aren't worth much)......The timing chain is in wrong.....If it was loose enough that it could have jumped time and he looked at it and it was 2 teeth off.....There would have to be much slack on one side of the chain while the other side is tight. When he looked at it probably the wrong side was tight.
Do a compression test, I bet it's way low on all cylinders....:corn:

rick,
i didn't get to see how loose it was, i just remember him showing me how the timing marks were not lined up......

ok so going back to the begining the very start of all of this;

so last week or week prior he went out to the driveway and started the truck he said the truck started real wierd and made a funny sound (his words) i can't remember if he told me he rev'd it and the sound went away or if he turned the truck off and restarted it and it started up normal ( i am going to guess he restarted it) he drove it and it sounded fine for a 2 days, then on day 3 he went out and the truck would not start....

we then checked the plugs, he cleaned them up and checked the gaps
we put the spark tester on there and the light flashed red every crank
he checked the TBI, we got fuel...
he sprayed starter fluid in, cranked didn't start.
he then changed the GEARS and CHAIN, in time.........nothing

he then got on comancheeclub.com and asked the guys there.. they too said CPS, changed that........... nothing

he then checked the distributor and checked for missing teeth... none found

now we are here.......

now there is another guy on comanchee club saying that he had the exact problem on a brand new crate engine and it was his distributor, so he is going to buy a new one and try that... also he told me today he was going to check the compression so we will see where that goes....

 

[trxguy]

Definitely sounds a lot like timing was not set properly...does it backfire, or do anything at all like it's trying to fire???

hey kevin there you are .. i thought you were going to jump in sooner.....anyway, no it does not back fire or even show signs that it wants to fire just cranks....then the battery died so we charged it up and it just cranks....ooooooo and we even tried jump starting from my diesel to it..that didn't change anything either :haha:

 

[zukkev]

Are you getting spark from the coil? To the plugs (all of them)? Now that I have the whole story...or at least a story line... I did have a dist whack out on me once on a customer's rig, but it at least tried to fire...backfired thru the intake...is the distributor turning when cranking????

 

[trxguy]

Are you getting spark from the coil? To the plugs (all of them)? Now that I have the whole story...or at least a story line... I did have a dist whack out on me once on a customer's rig, but it at least tried to fire...backfired thru the intake...is the distributor turning when cranking????

no never backfired.not at either end......yes the dist. turns.....and the head was replaced 6 months ago ... i just remembered

 

[trxguy]

kevin ....yes we checked all plugs with the tester...

 

[Binder]

You could have gas fouled the plugs from all the cranking.....