trying to fix bosses car

[skinner]

My boss has an 84 lincoln towncar/5.0. Told me it just died one day, wouldnt start but kept backfiring through throttle body. Naturally figured timing chain had slipped so ripped it apart and sure enough, wasn't dot to dot or even close. Installed new gears + chain, dot to dot aligned. No go. Replaced all plugs and cap/rotor. Getting spark, timing is unchanged, getting plenty of fuel. Problem is, it still won't run correctly. I was told an engine should run fine with the timing cover/water pump/fan/balancer off...is this true(for a few seconds at least)? I could get it running on its own just barely, but even then it ended in nasty backfires and plumes of smoke out the top and sounded horrible. I keep wanting to think that the timing is off, but by looking at the rotor in perspective to the crank gear, it looks about right. Any other ideas of where I can go from here? Must it be reassembled to run right? Sorry this may be in wrong section, but i'm getting desperate for ideas here.

 

[dusto2]

did you check to see if any of the valves got bent when the chain went just a thought not sure if thats a interference engine or not but a good thing to look into

 

[JFA_Spyderman]

+1 on the valve job

 

[Shoeboy]

Something that is rare, but our shop vehicle is a Jeep Grand Cherokee with 4L, but when it was given to us, it wasn't running worth a damn. after ripping it apart, we found that a lifter was worn to the point of having a hole, and the cam was ground down about .060" and that was enough for the engine to run like a bag of crap. We couldn't figure it out, it took us 3 times tearing the top half of the engine apart to find the problem, we knew it was mechanical, we had that going for us. Thats what happens with 40 000km oil change intervals, no wonder they just gave us the Jeep.

 

[Turbo-T]

A little time doing a compression check will tell you if a valve got bent. If a cylinder has low compression a leakdown test will show where it's leaking out at.

 

[Ranger5.0]

more diagnoses and less guessing lol. You said throttle body, so its efi? are the injectors working? good fuel pressure? ignition timing?

 

[MAKG]

Umm, carburetors always have throttle bodies as well. They just have a main jet blowing fuel between it and the choke.

I'd do a leakdown test as it's far easier to interpret. Pressurize each cylinder to 100 PSI at TDC/compression and listen for hissing at the carburetor/TB and exhaust pipe. Should be dead nuts quiet. While you're at it, remove the rad cap and make sure there aren't any bubbles in the radiator neck (very quick and very easy check for a blown water jacket). Note that there will always be some hissing into the crankcase as piston ring gaps are never zero. You only need a calibrated leakdown tester to test if that particular hissing is excessive; for other tests a simple spark plug hole fitting is adequate.

Does this thing have a timing chain tensioner? Is it in decent shape?

While you "can" run with the timing cover off, I suspect the chain oiler is going to make you rather unhappy. However, you might try turning the crank by hand (with a ratchet). The engine will run very happily cold for a few seconds with no water pump.

 

[almostclueless]

Valves are bent......leakdown will be horrible.



I've never seen a SBF with a tensioner incidentally. Ridicuous unnecessary plastic coated gears, yes.

 

[snake]

it could be 180 degrees off too... turn the crank by hand with the number one sparkplug out and a finger in the sparkplug hole. When you detect compression, bring it up to TDC and then pull the dist cap off and see where the rotor is pointing. If it isn't at number 1 then pull the distributer out and rotate the rotor so it is pointing at 1 on the cap.

You can also set the timing at this point by moving the crank from TDC to wherever the timing is supposed to be set (example, 8 degrees before TDC) and move the distributor until it lines up with number one. Bump the key and it should rip right off...

I wouldn't crank it without the harmonic balancer on... its what holds the crank timing gear on the crank ya know...

 

[skinner]

finally success. The distributor was a bit siezed in and could only be turned about 30 degrees with a large wrench. After trying everything else possible, and letting it soak for a few days, we were able to get the dist off and move it tooth at a time. Finally got it running. Must have been a couple teeth off, which i can't understand fully because the rotor looked like it was in the right position. In any event, finally got it running. In any event, thanks for all the tips guys, I tried them all.