jeep help!!!!!!!!!

[zukkev]

Something's not adding up...Spark's good....You have injector pulse? And fuel pressure is good? This is a long shot, but is the crank turning??? I have seen some really odd ones (not necessarily 2.5L) where the crank's busted..
If you have all these, you should get at least something indicating it's trying to fire...

 

[trxguy]

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

u are the second person to sugest that...thanks rick... he said he is going to pick up a cheap set and check that too

 

[TreeClimber]

wehe sprayed starter fluid in, cranked didn't start.
....

It takes 3 things for an engine to fire.

Compression.
Fuel & air.
Spark at the correct time.

Since it didn't fire with ether, it's logical to assume (god how I hate doing that) that it's not a fuel issue.

So after you do a complete compression check, and provided all are good, then you can assume (again, how I hate doing that) that you have a Spark issue.

Either you have insufficient spark, or you have it at the wrong time.

 

[trxguy]

It takes 3 things for an engine to fire.

Compression.
Fuel & air.
Spark at the correct time. thats 4 things maybe 5 :haha:

Since it didn't fire with ether, it's logical to assume (god how I hate doing that) that it's not a fuel issue.

So after you do a complete compression check, and provided all are good, then you can assume (again, how I hate doing that) that you have a Spark issue.

Either you have insufficient spark, or you have it at the wrong time.

i agree and everything you just said to me i have said the same to him...i have been posting everything he or we have been doing.....never know if there something we didn't think of, thats why this thread is here...
thanks

 

[TreeClimber]

i agree and everything you just said to me i have said to him...i have been posting everything he or we have been doing.....never know if there something we didn't think of, thats why this thread is here...
thanks

Pull number one plug, stick your thumb in the plug hole, and turn the engine over slowly with a socket-wrench. When you feel the compression blowing your thumb out of the hole, look down at the timing mark & at the distributor rotor.

I'm still wondering if you put the distributor in 180* off.

 

[Binder]

Not to distract from the issue at hand but why does a engine with throttle body injection have a crank position sensor? The purpose for a CPS is the function of sequential port injection.......

 

[trxguy]

Not to distract from the issue at hand but why does a engine with throttle body injection have a crank position sensor? The purpose for a CPS is the function of sequential port injection.......

I AM NOT A JEEP GUY i dont know **** about them except they look cool stretched with coilovers and comp cut fenders and a full non factory cage (cj,yj,and tjs that is)...

i am a toyota, ford, and chevy guy....i am just posting this, trying to help a good friend

 

[crash2]

Not to distract from the issue at hand but why does a engine with throttle body injection have a crank position sensor? The purpose for a CPS is the function of sequential port injection.......

You can have a crank sensor with non sequential injection. But all the ones I have seen have no pickup in the dist--just a different way for a trigger.

 

[zukkev]

This.....taken from a help site we use at work, on the timing thing...
.......Check the distributor sync by rotating the crankshaft clockwise to Top Dead Center (TDC). The rotor will be turning clockwise also. When the crankshaft timing mark reaches TDC, the trailing edge of the metal part of the rotor should be just past the #1 terminal in the distributor cap. Scope check the Crankshaft Position (CKP) Sensor and Camshaft Position (CMP) Sensor as it is losing spark and injector pulse......
is a quick and dirty check to see that ignition timing is at least close....Also, is the injector being pulsed by the PCM? You have a noid light set???

 

[89flat]

this is josh and this is my truck that matt is helping out with,
yes your correct about no pick up in the dist. thats what the CPS is for.

 

[TreeClimber]

This.....taken from a help site we use at work, on the timing thing...
.......Check the distributor sync by rotating the crankshaft clockwise to Top Dead Center (TDC). The rotor will be turning clockwise also. When the crankshaft timing mark reaches TDC, the trailing edge of the metal part of the rotor should be just past the #1 terminal in the distributor cap. Scope check the Crankshaft Position (CKP) Sensor and Camshaft Position (CMP) Sensor as it is losing spark and injector pulse......
is a quick and dirty check to see that ignition timing is at least close....Also, is the injector being pulsed by the PCM? You have a noid light set???

But on a 4 stroke motor, the TDC mark will occur twice per revolution of the camshaft/distributor. If the distributor is put in 180* off, then the rotor will be at #1 terminal, and the crankshaft will show TDC, but it will be on the end of the exhaust stroke/beginning of the intake stroke (when the valves are open)... yet it needs to be at the end of the compression stroke/beginning of the power stroke.

 

[zukkev]

But on a 4 stroke motor, the TDC mark will occur twice per revolution of the camshaft/distributor. If the distributor is put in 180* off, then the rotor will be at #1 terminal, and the crankshaft will show TDC, but it will be on the end of the exhaust stroke/beginning of the intake stroke (when the valves are open)... yet it needs to be at the end of the compression stroke/beginning of the power stroke.

Yes...it doesn't go into that much detail, but when you roll it to TDC while watching the rotor, you should be rolling the crank up on the compression stroke.... I remember something about the rotor not actually being lined up with the contact in the cap on these buggers.....

 

[zukkev]

this is josh and this is my truck that matt is helping out with,
yes your correct about no pick up in the dist. thats what the CPS is for.

Hey Josh....take us back to the beginning! Give us the rundown of what happened, and what you have done to try and resolve this...tests you have done...

 

[Binder]

I remember something about the rotor not actually being lined up with the contact in the cap on these buggers.....

It's to allow for timing advance while running.

 

[zukkev]

Yeah, I get that...but this motor is the only one I can think of where the initial setup is to have the rotor just after TDC...when the crank is on TDC...

 

[trxguy]

But on a 4 stroke motor, the TDC mark will occur twice per revolution of the camshaft/distributor. If the distributor is put in 180* off, then the rotor will be at #1 terminal, and the crankshaft will show TDC, but it will be on the end of the exhaust stroke/beginning of the intake stroke (when the valves are open)... yet it needs to be at the end of the compression stroke/beginning of the power stroke.

why are you stuck on the idea of the distributor being 180* out????????????

 

[1982cj7]

The rotor should be just past #1 when set up correct, it wants to fire just before tdc. If it is off the spark may be present but will not fire the engine, it is a weird thing with 2.5's and 4.0's. We cut out an old dist cap around #1 for setting them up. Have not seen the result of the compression test? Since it would do nothing with starting fluid it has to be timing(we have spark) or compression.

 

[zukkev]

...
when the engine is on top dead center of the compression stroke the rotor points to the number 1 firing position.

If this is the case, it's off per my later quote in the thread---as have a couple others...:awesomework:

 

[slednecks1124]

I had a similar problem with my YJ where I was driving down the road and it just died on me, would turn over with spark & fuel but would not start. It ended up being a bad relay, I couldnt tell you which relay cause my mechanic of an uncle fixed it for me:redneck:

 

[zukkev]

Fuel pump relay? I read about that being a possibilty too....but you have to know whether you're getting injector pulse or not (which we don't know the answer to that)...