69 225 V6 Hei Installation Help Needed

No, I haven’t. Short of removing the timing chain cover I’m not sure how, and I don’t know the second and third order effects of removing the cover (oil, seals, gaskets, others). I’d like to exhaust other more easier checks first, but I don’t know enough to know what these may be.

Of note, my wife suggested last evening that I likely have a bigger issue with the engine, but it’s not yet obvious what.

Tim

 

The first owner is my uncle, and he swears the engine never had any work other than oil changes and tune ups. So I’m assuming the engine is truly original. Okay, 51 years old, 82k miles. I understand a timing chain or the teeth can break but my brain struggles with a chain jumping...stretched I have to guess.

At any rate, I’ve never opened an engine. Certainly not removed a timing chain cover (rubs temples). What am I in for?

Tim

 

AS I stated before but didn't get a reply. Looks like you are ideling very fast from the timing light flashes. Anything over 650-700 rpm will begin to advance the mechanical advance built into the dist. Make sure your timing light (if equipped) is set to 6 cyl and not 4 or 8 cyl. If you bring cyl #1 to TDC and your timing indicator at pulley is reading off then either your damper has slipped or your chain has jumped a tooth. No need to remove timing cover yet.

 

My apologies for not replying, Walt. I don’t remember your earlier post, but there are no settings or adjustments on the light.

My idle is high and that does concern me. However, try as I might I cannot get the engine to idle at anything less than 1000 rpm or higher. Guessing the rpm as my tach isn’t connected. As soon as it drops it runs rough, coughs, backfires, and quits — all in about 1-3 seconds. Gun it and hold the accelerator open and it’ll run. I will connect the tach today if it’s compatible with the HEI tach connector.

Tim

 

Just for the sake of discussion, base on the data Greenshirt82 has given, how could the time have jumped a tooth? The OP has said he has tried to confirm the piston is at top dead center with timing mark at 0 degrees and both intake and exhaust valves closed? I can believe the timing set has worn to the point the cam timing is moving but I don't think it has jumped a tooth. This could be confirmed by bringing everything up on a compression stoke to 0 degrees. Then rotate the crankshaft backwards by hand while watching the rotor. Does it move with the movement of the crank or is there a delay and by how much?

 

Today’s update
Idle
Repeated initial conditions today and connected the tach. Let it warm up at high idle ~1200 rpm. Once temp was above 130* I tried reducing choke to get it to idle, but no dice. It died after a couple of backfires. Restarted, revved the engine to 2000 rpm then let it warm up some more while idling at about 1/2 choke and 1250 rpm.

Slowly reduced the choke and it idles at about 800 rpm. But very poorly. I was able to check the timing and it was easily 6-8* after TDC. Then engine quit. Not much time to check it either.

This felt like progress.

Tim

 

I suggest you prepare to pull timing cover and check condition of chain, gears and alignment of timing marks on cam and crank gears.

Here is something to think about and try Put timing marks on your vibration damper and align those with your TDC reference mark on timing cover.
Mark

 

At 82K miles I would bet you need a timing chain, but also lifters, cam and other valve train parts. You also have a vacuum leak most likely.

 

Thanks. This seems to be turning in to a major project...

Time to build a notebook with info like this as I plan the project out.

Tim

 

So...I’ll start w the vacuum leak checks once I can get it running. Based on last evening’s results my carb definitely is out of wack. I fiddled with the idle screw and was able to get it to idle closer to 800 rpm (need a touch lower 650-700) and the spark wad after TDC...so I’ll redo initial conditions with that info today.

But the valve train work...should I plan for a complete rebuild if I’m already in that deep? I had hoped to wait a couple more years for when I retired.

Tim

 

If you cant get the idle below 800 RPM, I bet you have a vacuum leak. Make sure all your lines are plugged off that need to be and your carb base is tight. A full rebuild is probably in order, but I would get it running and that may require some valve train repairs. A timing chain set is cheap and relatively easy to do. The cam and lifters is more involved. All the 225's I have taken apart had at least one crashed lifters and a couple round lobes on the cams. I would expect the same on this engine at 80K+ miles.

 

Ok, thanks.

I’ll lay out my plan and try to do this in stages. I don’t mind a redo on easy bits.

Tim

 

Update
I warmed up the engine, then adjusted the idle more, took quite a bit of idle adjustment to bring it down to 650-700. 2 full rotations of the adjusting nut.

I then used a propane torch wo flame around the base of the carb and along the entire intake manifold. No change in the idle. All bolts are tight.

I reset to initial conditions. Then manually advanced by one tooth to see if the -10* from last evening could translate to +8* today. No joy. Not a happy engine at all.

Reset to initial conditions again and at idle (650-700) the spark on number one cylinder is all the way over on the passenger side. I tried retarding by rotating the body clockwise but even a little caused rough running and a backfire. Full advance and it idles better, acceleration is smooth but with an occasional backfire. I cannot attach the vac because there is no space between the canister and the fan blades (well, about 1/16th “).

If it matters, at idle the timing light is intermittent to nothing. Like no spark on number one cylinder. When it does spark, it’s over on passenger side. My gaps are at 0.040...too wide or too narrow?

Tim

 

Tim, I am not a mechanic by any means. I just rebuilt my carburetor, there is a You Tube video on how to do it. Getting ready to re-jet it. I had a previous Jeep that I had to do a redo a timing chain on it, it was not hard.

The only thing is, you are going to need a place to do the work and tools. There are plenty of places to source information. The only other issue for you will be the financial part, which can make this progress slow.

I would start with the timing chain, gears. Anything you do here will not be wasted if you do a rebuild, you will be out some gaskets.

As much as you have been doing with the Distributor , I feel you can do other things.

 

Thanks for the support, Steve.

My garage at home is the only place I got. Right now the Jeep is backed in and I’ve got room to work. My SM says I can do the timing chain and sprockets and shouldn’t have to take the engine out nor remove the body. Tools? I’ve got most but nothing special. I’m on the fence with a full engine rebuild given I’m almost there with the timing chain and sprockets...and it would ensure the engine is in better shape (too many other noises I know should not be there).

Near term I may just focus on the timing chain and sprockets simply because I don’t have to remove the engine. It’ll possibly buy me a couple of years of driving. If that isn’t the issue, then I can cross the bridge of a rebuild.

My skills? LOL, I’m not afraid to do it, just time and space...and tools. I hate hitting a roadblock and then have to clean up to go buy a tool. When I was younger the nearby base (not this one) had an auto hobby shop with lift bays and all the tools I’d need. ISTR bay rental was $3/day. Plus lots of folks to provide thoughts and answers. Truth in advertising: I’ve never broken into an engine, but I have replaced oil pumps, carbs, and rocker assemblies (and now a distributor).

Tim

 

Update w video.

I was able to rotate the body clockwise, and the rotor with it, to keep it aligned to post one and attach the vac hose. Tweaked the idle again, just for good measure. She runs about the same as she did before the original distributor crapped itself. However opening the throttle now results in a backfire. Spark at idle is all the way over at 30*+ on the passenger side. I’m more convinced than ever that my timing chain is off in some manner. Plus there may be more going on as others have mentioned.



That knock has been there since I got her, back in 2012. That’s a new thread and a new problem for a different day.

At this point, I think I’ll hold off on more adjustments and take her for a short drive ti fill the gas tank. Any reason that’s a dumb idea?

Tim

 

Hi Tim,

In your video, that rattle we hear could be the distributor, but I'm leaning toward the timing chain.

There is a chain tensioner under the cover, mounted to the right face of the block, that presses against the chain. If the rubbing block is wore out, it will allow excessive slack in the chain, and could cause the timing to be very unstable.

When I replaced the timing chain in my 225, I installed an Edelbrock double roller chain, and a replacement tensioner.

Your results may vary, but it is worth a look.

Cheers!

Gary

 

The Allen screw that needs backed out is inside the vacuum fitting on the vacuum advance canister
That controls the amount of timing the vacuum pulls in and out.

To me it sounds like it's still off. It's an odd fire so not every 90 degrees fires like a v8 and not every 120deg like my 4.3 but it fires at 90 and 150. I think you still have some dead cylinders that are not burning at the right time. This loads up the exhaust with fuel and then pops when the hot exhaust hits it and that is heard in the muffler.

I want to see the reluctor and stator under the rotor it should have 3 points on one and 6 unevenly spaced on the other.

 

It's hard to tell if the noise in the video is the timing chain. The one in mine sounded like a diesel engine at idle with the loose chain slapping against the guides. It quieted up at higher speeds. It was running fine but I changed the chain because I hated the noise.

It can be done easily in the Jeep with the radiator pulled. Here's how loose mine was:



That's pretty bad.

The biggest issue you might encounter is the long water pump bolts can corrode and expand wedging themselves in the front cover. If they snap off, it can take some effort to get the cover slid off of them. It wasn't an issue on mine.

 

Hey @Greenshirt82 (Tim) - It's been a whie - just wondering how this all played out?