TC 5.0L Questions

[mcninetyone]

I worked on a 93 CV that had fuel lines so rusty from living on Ohio that the gas was seeping out right through the lines.
Once I actually touched them, they disintegrated.

[jaywish]

I am guessing the PCV tank you reference is the vacuum can? (A soup can on the TC's?) Also check the line between the check valve and the soup can. Mine was broken, fixed that, checked every other line, still didn't work. Finally HRG found the line collapsed shut. So though the tank didn't leak and the check valve checked, there were no leaks in the system at all, the tank never got emptied as the collapsed line didn't allow it.

Just bty I don't think the mpg's you are getting are bad at all for a TC. Hilly city/HWY. City I expect about 10-11 highway easy cruising 23 maybe.

[DerekTheGreat]

Cure the vacuum leaks, check the condition of the vacuum hose going to the MAP sensor and replace if necessary. Then throw wires, plugs cap & rotor at if you haven't already and set the base timing @ 12 degrees. You might be able to get away with 13 but 12 seems to be the safe number. I was running 13 and went back down to 12 because it would still ping at times and I not like that so much. Ashley's 89 was running 13 and pinged pretty much any time it was accelerating. She got great MPG though but I had to back off on the timing. Her '89 has a goofy angled timing indicator so I really have no idea what I set it to but I kept backing off until the ping went away under load.

[gadget73]

Not all of them will tolerate timing advance. Mine never has. The Mark VII doesn't like it either.

[86VickyLX]

Lopos gain nothing from a timing advance. Except for the most part a pinging under accel

[SirFoxx]

Cure the vacuum leaks, check the condition of the vacuum hose going to the MAP sensor and replace if necessary. Then throw wires, plugs cap & rotor at if you haven't already and set the base timing @ 12 degrees. You might be able to get away with 13 but 12 seems to be the safe number. I was running 13 and went back down to 12 because it would still ping at times and I not like that so much. Ashley's 89 was running 13 and pinged pretty much any time it was accelerating. She got great MPG though but I had to back off on the timing. Her '89 has a goofy angled timing indicator so I really have no idea what I set it to but I kept backing off until the ping went away under load.

What does pinging sound like? I already replaced the plugs, cap, rotor, and igniter. Where is the timing indicator on this motor? Also, I noticed that my harmonic balancer has a slight wobble to it--Will I need to replace it soon? Also, if I replace it, should I also replace the cam while I have it off?

If you've replaced the check valve and the vacuum can, the TBL is probably it. I usually just unplug those and cap the lines off. The TBL tee's right off the main source vacuum line going into the cabin. Possible its somewhere else, but thats the common major leak point that is also easy to fix. Beyond that you're getting into chasing nonsense through the control unit and beyond.


Check the parking brake release under the dash too. It commonly leaks. Not likely related to HVAC, but its another fuel eater

Examine all the rest of the lines while you're in there. Leaks on the MAP line majorly mess with how it runs and burns fuel. Check the timing and do a tuneup if you haven't lately. Would also be worth checking for codes, just in case that has something to tell.

Interestingly enough, someone has bypassed my heater core. So I have no heat..I doubt my core leaks since the inside of the car didn't smell like antifreeze. The PO may have done it because of the vacuum leak causing hot air to blow in the car on hot days. Where should I plug the 2 lines going to the heater switch thing...? Also, I thought my car was SD, not MAP... would there still be a vacuum line?

Not all of them will tolerate timing advance. Mine never has. The Mark VII doesn't like it either.

I don't think mine has been advanced. I was thinking about it, but never found time to mess with it.

[sly]

My lopo gained better idle and a slightly better off-idle response. But yeah... that's about it.

[DerekTheGreat]

Not all of them will tolerate timing advance. Mine never has. The Mark VII doesn't like it either.

Lopos gain nothing from a timing advance. Except for the most part a pinging under accel

My lopo gained better idle and a slightly better off-idle response. But yeah... that's about it.

I guess it all depends. On my GM vehicles it's easy to tell where the bloody timing is but on Fords it's goofy since they put the timing marks on the harmonic balancer and most irritating of all have weird angled timing indicator tab things. I really have no idea where either cars actually are now. My '88 seemed to be easier to read so I'm pretty sure that's at 12 degrees. Ashley's 89 though, stupid angled tab thing wasn't easy for me to read. Wasn't sure if it was the point to the left or right, so originally I went with the middle but after I was convinced the car was no longer pinging the mark I made @ 12* was showing up a smidge to the right of the righthand point, if that makes any sense. The mark started under the lefthand point, couldn't even see it at first so I ended up retarding it quite a bit. Car is probably @ 10 degrees now. Like Sly said though, both cars seem to be more responsive off the line, Ashley's car picked up some MPG but that could've been from back when I accidentally retarded her timing by a tooth, so when I got it right it was still more retarded then it should've been. My car still seems to average about the same.

What does pinging sound like? I already replaced the plugs, cap, rotor, and igniter. Where is the timing indicator on this motor? Also, I noticed that my harmonic balancer has a slight wobble to it--Will I need to replace it soon? Also, if I replace it, should I also replace the cam while I have it off?

Interestingly enough, someone has bypassed my heater core. So I have no heat..I doubt my core leaks since the inside of the car didn't smell like antifreeze. The PO may have done it because of the vacuum leak causing hot air to blow in the car on hot days. Where should I plug the 2 lines going to the heater switch thing...? Also, I thought my car was SD, not MAP... would there still be a vacuum line?
I don't think mine has been advanced. I was thinking about it, but never found time to mess with it.

If the harmonic balancer is indeed wobbling, replace it right away. The rubber inside it has probably deteriorated and thus it isn't long for this world. That's the pulley at the bottom of the Engine by the way. My Smog pump pulley wobbles but has ever since I've known the car, I have been ignoring that.

Pinging to me sounds like a bunch of small pebbles in a coffee can being shaken or rolled, kinda hard to describe but you'll know it when you hear it. I hear it best with the windows up, HVAC off and under slight load in 'D'. Not always so obvious under wide open throttle, for me anyway.

The timing marks will be on the balancer and the timing indicator will be off to the left side of the harmonic balancer if you're looking down at from up top. Don't ask me which point indicates the correct timing Had no idea Ford changed that year to year.

[sly]

taking some white paint on a thin brush to the hash marks in the balancer makes seeing those marks soooooo much easier. I only enhanced 0, 10, 15.

[DerekTheGreat]

That's what I did, but the tang or tab you use see where you actually are is hard for me to discern on her 89. Still somewhat goofy with my 88. Our GMC truck Is so easy by comparison; just one big channel on the balancer and the tang has individual points every 2 degrees IIRC up to 8.

[VicCrownVic]

taking some white paint on a thin brush to the hash marks in the balancer makes seeing those marks soooooo much easier. I only enhanced 0, 10, 15.

I usually use whiteout. Soapstone is another option or I suppose chalk would also work.

That's what I did, but the tang or tab you use see where you actually are is hard for me to discern on her 89. Still somewhat goofy with my 88. Our GMC truck Is so easy by comparison; just one big channel on the balancer and the tang has individual points every 2 degrees IIRC up to 8.

Next time I'm around I'll have to look and see what you're talking about on Ashley's car. The timing indicators that I have seen have all looked like what your car has.

[DerekTheGreat]

Yeah, it's probably something I over-looked and made out to be more complicated than it actually is.

[sly]

Thing I dislike about chevies is the rear dizzy.

[gadget73]

You have to get your head at the right angle to see that timing pointer. You're looking for the marks to be visible right at the flat edge. The actual point doesn't mean anything.

[DerekTheGreat]

Thing I dislike about chevies is the rear dizzy.

Yeah, that sucks, especially on big blocks. Two person job and it seems you have to account for it to retard itself by ~1 degree as you tighten the dizzy down.

You have to get your head at the right angle to see that timing pointer. You're looking for the marks to be visible right at the flat edge. The actual point doesn't mean anything.

My head was all over the place, no flat edge that I recall. I'll try and get pics today & upload them later, that'll probably help clear my stupidity for next time. Ashley reports that her car seems to start & idle easier & smoother and seems to be more responsive off the line. My car seems to be virtually the same minus the pinging I occasionally heard so perhaps I did alright.