Troubleshooting: Engine lacks high speed performance/ power.

[Axle Roads]

Richard, if you look closely in the hole you can see a flat seat where, I think, the seal is made. I might be wrong, but I'm guessing as long as the adapter is screwed in all the way it will seal. Poor design, if you ask me. I added plumper's thread seal just to be on the safe side... no difference. I want to try a rubber washer next. I can't get too the rear end without taking apart the carb so I don't have a way to test the vacuum.

I like your idea of buying a cheap carb for diagnostic purposes. It would still have to be a load-o-matic right?

I have a manual choke.

 

[MPGmustang]

it looks to be the autolite, for the 67-68years.... emissions crap if you ask me... i run an 1100v and a 65 LOM distributor with pertornix, no points... a carb is a carb, if it fits use it, honestly try to go for one with a auto choke i think it's nicer not having to constantly adjust the choke... i have a 1940 holley here that needs a rebuild, i honestly think that the ported vacum is what is casuing you trouble i think you need to get a replacement a rebuild only replaces internal components, not your threads... i know duck tape works wonders but i don't think it can fix this (then again i have been proven wrong countless times)

LOM only refers to your distributor... not the carb (someone correct me if i'm wrong) all carbs have the ported vacum that you need, and as such some have auto or manuel chokes.

Good Luck,
Richard

 

[MPGmustang]

how is your cap? the ball in the middle?

Is this in the carb?

it's in your distributor cap, there is a ball in the middle that the rotor touches, is it still there? my car ran like crap (but ran) with most of that ball missing, after a while sparks were flying in there also... burn marks show in gray...
-Richard

 

[Axle Roads]

Still there. The ball on the distributor cap is gray surrounded by brass. Both the cap and the rotor were replaced 10 months ago, but before the electrical upgrades. The rotor is starting to gray on the top. It also has more play than I'd like.

 

[Axle Roads]

• Verified TDC
• Rotor position = 3 degrees after cylinder #1 and oil flap.

I built a manometer and I'm absolutely sure that true TDC occurs just a fraction of a degree before the notch on the harmonic balancer lines up with 0 degrees on the block. The flat spot on the distributor shaft is about two or three degrees after the mid-point of #1 spark plug wire. Is that within tolerance? Like I said before the rotor wiggles around a bunch, if the shaft rotates clockwise dragging the rotor behind as I think it does than it's in reality spot on. This was my first time doing this so I could have done something wrong, but I did my homework and took my time. It's got to be something else.

Still working on the carb. What does that line to the transmission do? It's not on very tight at one spot. Does that down-shift on breaking or something else?

 

[MPGmustang]

The advance should be 8-12* before TDC factory it came 6*... it gives the best performance... because your not running with Vacum advance or much of it try disconecting it and advance the timing 18* or 20* and drive it like that, see if it's an improvment, if yes then you found the problem if not then you know it's not the vacum... a cap and rotor here costs less than $10, cheap enough to tighten that wiggle of yours. tip run the cap with the old rotor for a few heat-up/cool downs to break it in then install the new rotor... i broke a new rotor and a new cap at the same time...

the tranny vacum, try replacing the lines and see if that helps, lines are cheap enough...

Richard

 

[gb500]

hi -coming in late - and at work so havent read all the thread - but i gather you are running the loadomatic advance dist.

does the dist advance when you rev it ? as checked by a timing light on the timing marks?

reason i ask is that you talk about red hot exh manifold - sometimes a sign that the spark ( and consequence fuel burn) is continuing too late - sign of too retarded timing.

my loado dist had a hole in diaphram = no spark advance at all - ran cr@pola.- fixed that and still and no spark advance.
dist advance plate was stuck ( from not being used)- fixed that and still no spark advance...

turned out the running with a hole in diaphram had sucked in dirt all the way through the vac line and into the 'spark advance' drillings in the carb and blocked them.

cleaned out with carb cleaner and fine wire and presto -spark advance

may help

brett
melbourne

 

[gtm1086]

Plugged or restrictred exhaust. Do you still have the stock exhaust? If you do and it has been sitting for ten years it is probably plugged or restricted which will give you poor performance.

 

[Axle Roads]

Yes, the distributor does advance when I rev. I'm going to JB weld and clamp that carb fitting tomorrow, I guess it wouldn't hurt to flush the line with compresses air. While the epoxy dries, I hope to try to take out the distributor and reset it farther from the block. That would give me the option to turn it past 14 degrees at idle.

Exhaust setup: leaky, stock manifold -> 1.75" pipe ->large quiet muffler. It's a pretty rusty set-up but it flows well enough to remove condensation. Does anyone else think I should fixing this problem before installing the headers? I'm running out of thinks to do.

 

[MPGmustang]

try a new exhaust gasket, add ultera copper to both sides of the gasket, put alot on, be generous... very

i put this on and i still havn't had to retorque the bolts... but then again i did this with the head off to 40lbs to each bolt.

-Richard

 

[MPGmustang]

oh BTW has ANYTHING helped with performance?

 

[Axle Roads]

• sealed crack
• reset distributor
• posted spark plug pics here

I over did it with the cab cleaner and it backfired, literary. My top block burst into flames. I've since cleaned the whole engine compartment with Gunk citrus engine degreaser, WD-40 and a quick drying oil. It actually looks really good right now, but my engine wont start. I think some fire extinguisher foam may have found its way into the carb. I tried using starter fluid today until the battery drained.

I keep re-reading this thread, looking for something I've missed. I'm going to take lupin's advise too and address the possibility of an exhaust restriction. I'll let you know if anything helps, once I get it on the road again.

 

[JackFish]

Do you have a known good coil you could swap in?
It's getting fuel, right? When you look down the carb and pump the gas it squirts a bit?

 

[Axle Roads]

No, I don't have an extra known good coil. But, you set me on the right path. I checked the spark plugs, NO spark. I checked the point gap, YES spark. I think that means there's a problem with my condenser. I guess it's time to whip out the ohmmeter.

 

[Axle Roads]

Wow, my car sounds great! But, it's not fixed yet.

I took it on a few errands today, totaling 14.8 mi. At about the 10 mile mark I had to climb a big hill. There's no mistaking this problem when it hits, it's like trying to surf the net while your virus protection software is updating. Night and Day. I pulled off only a smaller road to let a VW pass by. While on the smaller road, I played around with the gear shifter. I figured out that if I shift my C4 into 2nd gear my original problem described above goes away. I suppose that tells me the problem's transmission related but... I don't know much about these transmissions. What should I look at first?

I don't have 700 bucks left in my budget so don't just say T-5 unless you think fixing the C4 would cost more than that.

Update:

• Exhaust done (Header to Y-pipe to 2.5" downpipe to turbo muffler to mandrel bent over-the-axle tailpipe)
• Parking Brake replaced
• Distributor cap replaced
• PVC valve replaced
• Condenser replaced

Found, RR parking brake was rusted on. But fixing it hasn't solved my original problem.

 

[Ricardo Velez]

I've been loosely reading this thread today, and have to say. I'm very impressed with the troubleshooting going on here..I ask myself and put it out here for your consideration:
I'm too, puzzled by the glowing exhaust, for sure a clogged exhaust or timing issue.
But, I wonder, since this is a low mileage rebuilt engine: is the camshaft really where it should be? a timing chain issue maybe...engine rebuilt and chain replaced?
easy to verify: whatever cylinder is at valve overlap, opposite to #1 TDC, has to have the rocker arms dead even( at TDC #1) slightly off seat, so just pulling the valve cover and turning the engine with a wrench to timing mark 0( zero), should put cyl # 6, ( 1-5-3-6-2-4 firing seq) on overlap, and both rockers for that cyl partially open, and dead even.
comments?
Ricardo

 

[MPGmustang]

have you replaced the entire vacum line from the intake manifold to the tranny? it there is a leak in this line shifting is not accurate, if this does not fix it, i would rebuild or replace the tranny... but it sounds like the engine runs GREAT!!! it's driveing that you're haveing a probelm on... for craps and giggles i would do what ricardo said also...

-Richard

 

[Axle Roads]

Not yet, I ordered a new vacuum modulator line. I hope it come in soon.

is there a new noise that you're not used to? from where? what's the sound? when does it occur?

There was a noise six months ago, from the flywheel, like a pulsating grind, occurring during quick acceleration. The noise would oftentimes coincide with a loss of power at the wheels. I tracked it down the noise to the bolts on the flywheel hitting the dustpan. I suppose something was causing my flywheel to move forward. I don't know what. I checked the nuts on the flywheel and they appeared tight. For a quick fix, I gridded down the bolts on the flywheel flush with the nuts; I haven't heard the noise since. I wonder if it's related.

I've been reading the archives and learning all I can about these transmissions. I just found this trans kit. Is there anything else I should replace, closer to the flywheel?

 

[Stubby]

If the flywheel moved forward, you need to check the thrust clearence.
Remove the dust cover on the trans and release the tension on the belts. Then try to pry the crankshaft forwards and backwards. The factory clearence should be about .005". If it has alot of movement, the thrust surface on the crank is worn and the converter is bad.

 

[Axle Roads]

Which belts stubby? You don't mean the the alternator fan belt, do you?

I forgot to mention that I tried to wiggle the flywheel back and forth with my hand and it seemed tight. However, I didn't loosen any belts or pry anything with a lever.

From what I've read so far I should probably replace the torque converter at the same time as rebuilding the transmission, anyway. When you say the crank maybe worn. are you talking about the this input shaft?