I’ve got a sinking feeling...... ELB TQ
- Thread starter 73 T&C
- Start date
Nice NewYorker........
Are you seeing a pattern here???
People ask me all the time if my Beautiful New Yorker is actually a.....Lincoln.
And I’m sure I’m not alone.
Dial in update.
Drove the NYB all day after re-sinching the carb back to spec. early this morning.
No fuel leaks and initial low throttle surge is almost gone.
Not banging into gear. Reduced the idle a bit and the mix a bit more and also reduced the fast idle.
Got home and worked a bit more on the idle settings.... lower all around a tiny bit more.
To make adjustments on a hot 440 you need one of these:
Unless you have asbestos fingers....
Result...
Better and.... smoother.
Now Officially running better and smoother than Peter Clancy’s ‘77 400 cu.in. Newport with the Edelbrock and electronic ignition.... and a whole lot faster!
NOS plugs going in tomorrow and I’ll even index them for those 2 extra ponies.
Why?
Because.....
I am Spartacus
Drove the NYB all day after re-sinching the carb back to spec. early this morning.
No fuel leaks and initial low throttle surge is almost gone.
Not banging into gear. Reduced the idle a bit and the mix a bit more and also reduced the fast idle.
Got home and worked a bit more on the idle settings.... lower all around a tiny bit more.
To make adjustments on a hot 440 you need one of these:
Unless you have asbestos fingers....
Result...
Better and.... smoother.
Now Officially running better and smoother than Peter Clancy’s ‘77 400 cu.in. Newport with the Edelbrock and electronic ignition.... and a whole lot faster!
NOS plugs going in tomorrow and I’ll even index them for those 2 extra ponies.
Why?
Because.....
I am Spartacus
70bigblockdodge
Old Man with a Hat
I am making a bastard TQ out of I think 2 whole carbs and some misc parts I have. I'm using the smaller bore version. Metering rods out of a 83 360, 1+ton truck (thinner in middle and top steps) fattening my cruise and part throttle. Secondary jets from 440 LB, 360 truck carb had small secondary jets. These LB TQs we're not meant to be lean at WOT just cruise and part throttle. The truck carb has that funky air horn with the electric/vacuum vent, with no practical way to adapt that to a 1968 car it's getting replaced with a conventional air horn. I also need to drill a port for ported spark advance ELB did not have one and truck base plate is really beat. I have been going back and forth about idle richening circuit since I am eliminating the LB and just running a manual choke cable (no heat crossover), it's benefit would be very little.
I also know that at WOT the A/F ratio can be changed by bending the stop tab on the air valve on the secondaries. Because the v bumps on the rear of the air valve create the low pressure area that draws fuel from the secondary circuit. Changing the angle of the valve/flap changes the area/low pressure to draw more or less fuel. So a slight lean or rich condition at WOT can probably be tweaked by air valve angle, quick and easy.
I also know that at WOT the A/F ratio can be changed by bending the stop tab on the air valve on the secondaries. Because the v bumps on the rear of the air valve create the low pressure area that draws fuel from the secondary circuit. Changing the angle of the valve/flap changes the area/low pressure to draw more or less fuel. So a slight lean or rich condition at WOT can probably be tweaked by air valve angle, quick and easy.
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Man..... that is one Frankenstein of a TQ you’re building there. The later TQ’s (78 and on) were actually a little richer running than the 77 and late 76’s. They needed to be to fuel the catalytic converter. The benefit of a TQ is and was better metering throughout the range and a fat WOT for those engines that could use them. My 340 is tuned to be fairly lean even at WOT. Because too much of a good thing is never good for power IMO.
Thanks for sharing!
Javier
Just drove home from my Sister’s house.
Surge is back.
It’s not the carb... I’m sure of it.
More tomorrow.
Surge is back.
It’s not the carb... I’m sure of it.
More tomorrow.
commando1
Old Man with a Hat
Describe your surge.
As in, you're trying to maintain exactly 60mph and your right foot is absolutely rock steady, and you feel the engine surging in a precise cycle?
70bigblockdodge
Old Man with a Hat
I believe from the parts I have and the way the engine is built I will be close. The A/F ratio guage will tell and then I can tweak it from there. If something is way off I have extra parts and drill bits, solder, and files. I'll make it work.
commando1
Old Man with a Hat
You two guys are looking for fuel injection performance from a ThermoQuad. Amazing. And I mean that in a complimentary way.
Dave, your TQ mods are eye opening.
Dave, your TQ mods are eye opening.
Yes
Reading up on possible causes, I dropped the timing two degrees to make the ignition less critical. Smoothed out some and was able to drop the RPM a bit to 825 but the in gear drop made the idle unstable.
Any low RPM load is enough to upset the idle until fully warmed up.
I’m chasing another issue I fear.
Meantime, as I was waiting for the engine to cool to check the wires and swap about the plugs... I kept busy.
These little bits of trim have been needing paint since I got the car.... I figured why not now.
And... yes.... I did both sides.
Paint used is exterior trim from SEM in semi-gloss.
I found one bad wire with a loose connector at the distributor. Plugs were fine. Checked the gap on the pickup in the distributor. It measured out at .008 as per spec.
Good if disappointing day.
I’ve got something going on in the engine. Bent pushrod from the backfiring when the Spark computer started dying.??? Bad lifter, burnt or bent valves???who knows.
Exhaust is hot out of the pipe. Much hotter than Normal I think. And puffing intermittently.
Will bang on it a bit more as I get what I need together for the leakdown test.
Any low RPM load is enough to upset the idle until fully warmed up.
I’m chasing another issue I fear.
Meantime, as I was waiting for the engine to cool to check the wires and swap about the plugs... I kept busy.
These little bits of trim have been needing paint since I got the car.... I figured why not now.
And... yes.... I did both sides.
Paint used is exterior trim from SEM in semi-gloss.
I found one bad wire with a loose connector at the distributor. Plugs were fine. Checked the gap on the pickup in the distributor. It measured out at .008 as per spec.
Good if disappointing day.
I’ve got something going on in the engine. Bent pushrod from the backfiring when the Spark computer started dying.??? Bad lifter, burnt or bent valves???who knows.
Exhaust is hot out of the pipe. Much hotter than Normal I think. And puffing intermittently.
Will bang on it a bit more as I get what I need together for the leakdown test.
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commando1
Old Man with a Hat
I'm losing track of the multiple issues, now.
70bigblockdodge
Old Man with a Hat
Does it hold rock steady vacuum at idle?
Needle trembles a bit... hardly noticeable.
70bigblockdodge
Old Man with a Hat
I'm out. I do like Jeff's dynamic compression test.
I’ll start with that.
So.... last night I saw a leak on the passenger side of the carb. There was a drop of fuel on the end of the primary throttle shaft.
My wife came out and asked what the problem was.
I said fuel leak.
She said “I’ll clear the counter”
Pulled another “spare” TQ out of the bin and got to work.
What I thought was a scratch near the repaired main jet well was actually a crack.
Actually two. You can just make out the second one toward the bottom of this picture
Swapped out the jets on the replacement phenolic base and put it back together.
I also adjusted the floats up a bit from 13/16” to 27/32” as that was the height for the floats on the original carb. Still no info available or found for the 9180s recall replacement.
Got curious about the EGR and looked down into the manifold. And noticed the passenger side has a screwed in plug for the exhaust bleed into the manifold.
The driver side still shows the old passage but it is not threaded and appears to be blanked off in casting. No threads cut.
Refinished the air cleaner lid while waiting for car and carb to cool.
Put it all together last night and it ran better... not perfect..... but better.
Surge is completely gone but I definitely have a weak cylinder. On power it is smoother. Off power; on idle it’s still off.
Let’s see where this goes. Still checking coolant for possible loss and blown head gasket and thinking possible weak lifter or pushrod issue. If it’s a burned exhaust valve or bent valve, it is slight. Still NFG but slight.
Started up eagerly this morning. High cold idle was a bit too high (adjustment made) and finally.... no banging into gear. Still a bit of a thud but not a big deal now.
Transition to operating temp was smooth and now acceptable.
I feel confident that the TQ is now well sorted.
My wife came out and asked what the problem was.
I said fuel leak.
She said “I’ll clear the counter”
Pulled another “spare” TQ out of the bin and got to work.
What I thought was a scratch near the repaired main jet well was actually a crack.
Actually two. You can just make out the second one toward the bottom of this picture
Swapped out the jets on the replacement phenolic base and put it back together.
I also adjusted the floats up a bit from 13/16” to 27/32” as that was the height for the floats on the original carb. Still no info available or found for the 9180s recall replacement.
Got curious about the EGR and looked down into the manifold. And noticed the passenger side has a screwed in plug for the exhaust bleed into the manifold.
The driver side still shows the old passage but it is not threaded and appears to be blanked off in casting. No threads cut.
Refinished the air cleaner lid while waiting for car and carb to cool.
Put it all together last night and it ran better... not perfect..... but better.
Surge is completely gone but I definitely have a weak cylinder. On power it is smoother. Off power; on idle it’s still off.
Let’s see where this goes. Still checking coolant for possible loss and blown head gasket and thinking possible weak lifter or pushrod issue. If it’s a burned exhaust valve or bent valve, it is slight. Still NFG but slight.
Started up eagerly this morning. High cold idle was a bit too high (adjustment made) and finally.... no banging into gear. Still a bit of a thud but not a big deal now.
Transition to operating temp was smooth and now acceptable.
I feel confident that the TQ is now well sorted.
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I was wrong. It was the carb. Or more precisely, the float level. Crack and leak just made it impossible to tune. IMO
Logic behind suspected weak lifter... and other theories...
Symptoms:
Car shows 99000 miles and heads looks to have been done sometime in the recent history of the car.
No noise at start of a collapsed lifter at all. Although initial start is eager it takes a moment to stabilize. Will sometimes buck (as in a no fire) but not always.
Cold (engine oil at max viscosity) hardly noticeable. Oil pressure would be high.
Cold enrichment of intake and high idle may also mask..... Maintaining max oil pressure.
Warm up.... problem begins as soon as engine is off the cold idle and enrichment. This has been since beginning but with a lot of collateral issues around it.
Warm on power hardly noticeable but feels like a cylinder missing or disconnected only much much less so.
Fully warmed up, temp has been in the operating range for 20 minutes or more. Oil viscosity now at its lowest, off power symptoms are mitigated but still there.
Idle now a slightly unstable 650 rpm with A/C on and trans in gear.
Revving engine reveals slight vibration.
Slow climb in revs negates the vibration completely at about 1600 rpm.
Theory 1:
Weak lifter becomes more apparent as oil thins and weak lifter is not able to give full lift. By weak lifter I mean an internally damaged lifter that does not allow it to maintain full height (broken spring, stuck check valve, obstructed blocked inlet). Becomes more even as oil gets hot and all the lifter lose a bit of their lift. Buck may me be caused by weak lifter remaining compressed and/or partially leaked down at engine shut off cycle.
Theory 2: bent pushrod.
Slightly bent pushrod would do the same.
Theory 3: spun lobe on cam.
Similar issue but would be constant.
Theory 4:
Fuel leaks washed out cylinder and dropped compression in one or more cylinder unbalancing engine. This is the easiest to deal with as compression will come back almost completely to affected cylinders as the rings reseat themselves with normal wear. (Had a float sink on a Weber that washed out a cylinder.... it came back 99% after several thousand miles of the condition) meantime.... Added a zinc additive to see if that helps.
Theory 5: hidden vacuum leak.
At this stage it would have to be WELL WELL hidden.
Theory 6: short block is just plain worn out.
Not likely given compression test done early on.
Nothing is off the table.
Need to check, from easiest to hardest:
oil pressure at different temps
Smoke test for hidden vacuum leak.
Compression
Leak down
Valve train movement/springs/pushrods.
Main bearings
Symptoms:
Car shows 99000 miles and heads looks to have been done sometime in the recent history of the car.
No noise at start of a collapsed lifter at all. Although initial start is eager it takes a moment to stabilize. Will sometimes buck (as in a no fire) but not always.
Cold (engine oil at max viscosity) hardly noticeable. Oil pressure would be high.
Cold enrichment of intake and high idle may also mask..... Maintaining max oil pressure.
Warm up.... problem begins as soon as engine is off the cold idle and enrichment. This has been since beginning but with a lot of collateral issues around it.
Warm on power hardly noticeable but feels like a cylinder missing or disconnected only much much less so.
Fully warmed up, temp has been in the operating range for 20 minutes or more. Oil viscosity now at its lowest, off power symptoms are mitigated but still there.
Idle now a slightly unstable 650 rpm with A/C on and trans in gear.
Revving engine reveals slight vibration.
Slow climb in revs negates the vibration completely at about 1600 rpm.
Theory 1:
Weak lifter becomes more apparent as oil thins and weak lifter is not able to give full lift. By weak lifter I mean an internally damaged lifter that does not allow it to maintain full height (broken spring, stuck check valve, obstructed blocked inlet). Becomes more even as oil gets hot and all the lifter lose a bit of their lift. Buck may me be caused by weak lifter remaining compressed and/or partially leaked down at engine shut off cycle.
Theory 2: bent pushrod.
Slightly bent pushrod would do the same.
Theory 3: spun lobe on cam.
Similar issue but would be constant.
Theory 4:
Fuel leaks washed out cylinder and dropped compression in one or more cylinder unbalancing engine. This is the easiest to deal with as compression will come back almost completely to affected cylinders as the rings reseat themselves with normal wear. (Had a float sink on a Weber that washed out a cylinder.... it came back 99% after several thousand miles of the condition) meantime.... Added a zinc additive to see if that helps.
Theory 5: hidden vacuum leak.
At this stage it would have to be WELL WELL hidden.
Theory 6: short block is just plain worn out.
Not likely given compression test done early on.
Nothing is off the table.
Need to check, from easiest to hardest:
oil pressure at different temps
Smoke test for hidden vacuum leak.
Compression
Leak down
Valve train movement/springs/pushrods.
Main bearings
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Wow... I keep missing this thread... start with the smoke, IMO it's the easiest and may show something fun. Without noise or an oil light blinking, I'm a touch skeptical about oil pressure problems... and would address the thought with a new filter before doing any other diagnosis. Too many failed bypass valves in my experience to start anywhere else.
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