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Need help with engine in Rancho Penasquitos

SanDiegoXJ

SanDiegoXJ

NAXJA Forum User
Location
San Diego, CA
Some of you may know that I had an engine rebuilt by Mike Finch some time ago. Since that time, the Jeep has had a vibration it never had before. It had also developed a leak in the front transmission seal and transmission pump seal.

So I pulled the timing cover, valve cover, and oil pan to inspect all the parts I could. Everything seemed to be in order, so nothing was changed except the gaskets. I also dropped the transmission, changed the oil pump, installed a new torque converter and flex plate, and put it all back together.

I started it up today and the engine doesn't want to run. When I crank it, it just rattles and dies. If I give it some gas, it doesn't hold a steady rpm, but increases and decreases harmonically by about 500 RPM. If I move the distributor back one tooth, it idles without assistance, but it backfires and won't go above 2000 rpm.

Anyone got some time to swing by and take a look today or tomorrow? I'd love to get some other opinions.
 
sounds like the distributor is 180° off, same thing happened when me and ryno swapped the motor in my MJ. it would either idle and not rev, or rev and not idle.

what year is it? I would start by verifying TDC with the valve cover off and making sure #1 is firing when its supposed to.
 
Yeah, I kept thinking 180 off too. I shoved my finger in the hole and cranked the engine by hand, and when air pressure built up, I considered that compression stroke, at which point I continued to rotate the engine the next few degrees until the balancer was at 0. I checked with a chopstick to make sure it was as high as it could go.

When it was still running rough, I put the compression guage on it and cranked one full revolution with no reading, next revolution pushed the needle to 15lbs. So second turn confirmed I was on the compression stroke again.

I'm a little concerned that it's something like the flexplate they sent was for a 4 cylinder and not a 6 cylinder...if that even makes a difference.

EDIT: Sorry, it's a 94 Country.

And just to note, the only thing that changed in all of this was front crankshaft seal, timing cover gasket, valve cover gasket, oil pan gasket, flex plate, torque converter, transmission oil pump and seals....and I pulled the distributor. The vehicle was offline in the garage for over 2 months though.

Also, when they rebuilt it, they put in a hotter cam. Would that require me to advance the timing at all?
 
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OK, Grimm, nobody else chimed in so I figured what the hell.

Pulled the distributor again and spun the crankshaft another 360 degrees and restabbed the distributor....won't even start....just cranks till it backfires.

Spun another 360 and restabbed it and it's back to where it was.

What gets me is the harmonic cycling of the RPM even at steady throttle.

And the thing idled so smoothly before pulling the distributor....wish I would have just let it be...20/20 hindsight
 
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EDIT: Should add that Mike is coming over if he can get some time to look at, but anyone else is certainly welcome to swing by and give me their two cents over a beer.

I need this running asap as the Hyundai needs a clutch and release bearing, and the Suzuki just started vibrating like a crack whore in need of a fix. Need one piece of transportation running solid.
 
have you taken the cap off and made sure the rotor is pointing where it's supposed to be in relation to your plug wires? we had to move them all over one spot.
 
Yeah, I've checked, and rechecked, and rechecked again.

I can't find what I'm missing...but I also feel like I just keep looking at the same stuff.

That's why I want a second set of eyes...hoping someone stops by, takes a look, and goes, "Um, if you don't plug this back in, the engine won't run"
 
This may sound really dumb, but you asked for two cents...I had an old Datsun pickup that did that but it wasn't after a motor change. My dad and I spent two weeks trying to figure out the cause. A friend was a certified BMW mechanic and came over. It took him 5 minutes to figure out the catalytic converter had failed and blew a buncha of the screen and honeycomb crap in one spot and was plugging the exhaust.

So, might be the rattle you were hearing (the junk in the cat) and now the engine issues. It's worth a shot if you haven't taken the cat off to take a peak and it might only take you an hour to check. Good luck!
 
Quick question about distributor install...

I pulled it several times, tried spinning it one tooth forward, one tooth back, 180 degrees out, etc.

But as I'm reading on distributor installation, it keeps talking about a plastic alignment pin that needs to be removed after install.

Could I have knocked the distributor out of alignment?
 
1904-96xj said:
So, might be the rattle you were hearing (the junk in the cat) and now the engine issues.
Click to expand...

Actually, it got a brand new exhaust in the change. New stock style header to replace the borla header, new downpipe with gasket, new cat, new muffler, new tailpipe....have to pass smog soon. =)

And the rattle I was talking about was the engine, not exhaust. The whole damn thing vibrates around and sounds like crap.
 
Yeah, but I've stabbed this thing three ways to sunday...I'm getting concerned that the new flex plate wasn't indexed correctly or you actually can install a flex plate more than one way
 
as long as the flex plate is from the correct year range that shouldn't be your issue. the holes in the ring on the flex plate's outer edge are different distances apart depening on the CPS its designed to be used with. As far as I know you cannot install it wrong, as long as the holes on the plate line up with the crank you're good. I've never payed attention to what orientation the flex plate was in when replacing them.

is everything tight in the distributor? a bit of up and down play is ok, any side to side whatsoever is not ok.
 
yeah, everything is snug...the only thing I can think that got damaged was the o2 sensor. I have a spare somewhere I'm going to try and find and see if it makes a difference. It really sounds like it's trying to adjust itself to run right, and at higher rpm it sounds nice, which is why I keep thinking sensor. exhaust and plugs smell like gas too.
 
Not sure if I mentioned but the flex plate is new, like brand new. ATP part number Z-339. Says it's for JEEP CHEROKEE 95-91 L6-4.0L Auto Trans Flexplate.

I guess it could be a faulty part, but I've gotten parts from ATP before and never had an issue.
 
Well, Mike came by last night and double checked my work for me. He moved the dizzy one tooth back, but it still ran like crap. He agreed it was a timing issue, but it wasn't the distributor.

New CPS showed up today, just installed it. Purrs like a kitten.
 
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