Diagnostic Now....Broke XJ shaft, melted rotor. Cause?

[dhcomp]

Fuel Pressure Regulator is adjustable, and has a gauge on it now, so when it primes, i know what pressure it is running at.

Cat is a possibility, will check it out.

Keep the ideas coming!

 

[Slapperbar]

Ignition Module.

umm

 

[Z71paramedic]

Only reason I mentioned the cat is that I had a similar experience with my wagoneer as Fordums nephew. It ran but really poorly. At the point I figure you're probably willing to try just about anything. Hopefully we can get it figured out soon though, I know this is a very frustrating time for you.

 

[dhcomp]

Thanks man. This motor is hurting, but trying to keep my house buying dreams alive by not buying another truck right now. Its been spewing oily moisture out the exhaust for a little while now. I often back up close to my garage door, remote start it in the AM, and let it run. You should see the door....

 

[Burbdood 74]

I don't know if anybody has mentioned it, but what about the pickup coil inside the distributor? I've seen pickup coils just die while driving down the road and it acts as if somebody just flipped off a light switch like yours did.

 

[dhcomp]

I don't know if anybody has mentioned it, but what about the pickup coil inside the distributor? I've seen pickup coils just die while driving down the road and it acts as if somebody just flipped off a light switch like yours did.

Think this is why I had to put a distributor in last week. Cause the pickup in the old one died.

Would i still be getting spark with a dead pickup?

 

[Burbdood 74]

Think this is why I had to put a distributor in last week. Cause the pickup in the old one died.

Would i still be getting spark with a dead pickup?

When the pickup coil died on my 86 F-250, it would fire up after it cooled down but it would die again once it got hot. Then after 30 minutes or so, it would be cooled off enough that it would fire up again.

Another idea: maybe you popped a fusible link somewhere along the line.

 

[dhcomp]

Another idea: maybe you popped a fusible link somewhere along the line.

Thought about that too. The main one i'm aware of feeds the whole interior / fuse panel though, and everything powers up. If i'm getting fuel and spark.....only thing that might not be getting power is the computer? But, i can read the codes, and get the 12 "you are in diagnostic mode" code, so thinking it is all working as it should.

Don't at all mean to shoot down people's ideas, just trying to respond with what I've done. Keep them coming guys!

Keeps me sane before I can get home, and go through the outstanding possibilities....

 

[black dawg]

I do have a timing light, but no idea what it is while trying to start. Yes, spitting a bit, backfired once. But, how would the timing have changed suddenly, unless it skipped a tooth? It ran fine. Was hesitant to mess with the timing because of it running fine before it quit. But really, that is probably the next thing.

Moved the plug wires over one wire to make sure it wasn't in a wierd spot, and it did nothing.

ECM was new a couple months ago, delco unit...but could still be bad. No codes to read, after disconnecting the battery...but it does go through its self check and flash 12.

I have seen 5 stripped distributor gears this year. All tbi and vortec motors. I would put a timing light on it with the esc wire unhooked. If the spark is getting to the plugs, and on time, with the injectors squirting it should run.

 

[dhcomp]

I could have easily stripped the gear on the "new" distributor. But, it still spinning.

Going to do it again tonight, but when i hooked up a timing light, EST wire unhooked, and cranked it, the timing mark was no where to be found with the light. Making it sounds like the timing was off due to skipped chain, or stripped dist.

 

[y5mgisi]

Yea, thats a full on no good type scenario. It should be right at 0 with that wire disconnected.

 

[dhcomp]

Yea, thats a full on no good type scenario. It should be right at 0 with that wire disconnected.

Or at 4ish degrees, where i timed it. Just wasn't sure if you could take an accurate reading with the motor not running.

 

[black dawg]

the ones that I have seen were not completely stripped, but munched enough that the gears had slipped.

Is it very common for timing chain issues in tbi motors? I have never seen a tbi timing chain fail. I have a burb with 300k on the original motor and I am starting to wonder about the chain.

 

[4X4HIGH]

Darren, IF I can afford some free time this weekend i'll call you and see if I can come over and find your issue for you. You'll owe me a good dinner if I can figure it out for you.

 

[Fordum]

I am starting to suspect that new dizzy. It sounds like a ignition timing problem. Especally if you can't find the TDC mark with the timing light.

I'm just not sure what would have gone wrong. Normally I would think that the gear loosened on the shaft, or did not play well with the cam gear and got chewed up.

But, if that had happened I would not expect the rotor to line up with no. 1 at TDC.

Unless it somehow jumped 180 degrees.........

So, I'm now thinking pickup, since the module seems to be good.......

Pop the cap again, and grab the shaft and see if it feels loose, or if the pickup will move or the trigger is loose on the shaft.

 

[dhcomp]

Darren, IF I can afford some free time this weekend i'll call you and see if I can come over and find your issue for you. You'll owe me a good dinner if I can figure it out for you.

Haven't forgotten the instructions you PM'd me Scott. Plan to work on it on Saturday. You've already earned a good dinner putting up with all my diagnostic calls, so no complaints there! Was going to pick you up a gift card for all the times you've saved my ass already....

Give me a call, and let me know if have a bit of free time.

Had to change radiator hoses, tstat, and water pump on the BMW. Front hinged hoods may look cool and be safe, but they SUCK when it comes to doing work on the front of the motor. And, of course, when it rains, it pours. Roommate sells extra truck, i sell extra truck, burb breaks down, BMW starts puking coolant

 

[y5mgisi]

When are you going to have time to try diagnosing it more? Im very curious to see what the timing comes out being, and then, curious to see what a compression test comes up with.

EDIT, Just for fun here is what a worn/stripped timing set looks like. You can see how although the teeth are catching the chain, how they can/will skip. Now, what i dont know is if that pic is of a gear that was originally nylon toothed or not, and if the 91 would have originally been nylon toothed.

 

[dhcomp]

When are you going to have time to try diagnosing it more? Im very curious to see what the timing comes out being, and then, curious to see what a compression test comes up with.

EDIT, Just for fun here is what a worn/stripped timing set looks like. You can see how although the teeth are catching the chain, how they can/will skip. Now, what i dont know is if that pic is of a gear that was originally nylon toothed or not, and if the 91 would have originally been nylon toothed.

Thanks helpful, thanks. May spend a few min on it tonight. Spent Saturday going to Santa Rosa to look at a newer truck, and yesterday on the coast with a lady friend....

It'll get fixed, whether i get a newer truck or not.... Need to get it moving though, its blocking 3/4 of my driveway.....heavy bit*h to push around!

 

[y5mgisi]

Actually, just got myself thinking. Seems like you were talking about your truck being kinda down on power and sucking gas just before this happened right? I wonder, if its possible, that you might have skipped A tooth or two initially (or a distributor tooth) which brought the truck into a weakened state only to then have it let go the rest of the way later on and thereby killing it the rest of the way?

 

[y5mgisi]

heavy bit*h to push around

I hear that!!! Last time i had to back my suburban out of the garage (to sell the old motor) and push it back in, i strapped the front bumper of the blazer to rear bumper of the burb (Tight. Like ratchet strapped the two vehicles together) and backed it out and put it back in that way so that i didnt have to push the dang thing!