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I'll raise my hand first. I spent 3 months of weekends trying to solve this issue. My engine began hitting a wall at WOT doing 4K rpm. Almost like a rev limiter I never had! I began with ignition by examining cap, rotor, coil, wires, plugs. Nothing. Then moved on to carburetor. Checked fuel filter, air horn for warpage, air horn gasket for tears, base gasket leaks, air valve interference, power piston stiction, throttle cable adjustment, etc., etc., etc.

Finally I remembered I installed a fuse protected 12v feed line for an electronic ignition upgrade 5 years prior. Sure enough a 25 cent fuse was the source of my exasperation. Ignition was functioning on the original 6v resistor wire I left in to act as a "limp mode" feature. New fuse and voila! Back to normal. Geeeeze. I guess I really over-thought that one or my mental powers are diminishing with age!

Anyone else have a humbling saga to share?
 

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Brakes on the '39 were locking up. Changed flex lines, calipers, 2 lb residual valve, masher cylinder and booster. Problem still there. Got in touch with MPB and he said to check the booster. Didn't make much sense to be because it was new and problem there before changing it. Took the booster out for the upteenth time and hooked a vacuum pump up to it. Sure enough, I could push the rod in and the rod on the M/C side would stick out BUT when I released the rod the other rod would not retract all the way. Checked the old booster and same results. Two 8" duel diaphragm booster with the same problem. There goes several months and $$$$.
 

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Race it, Don't rice it!
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Everyday....

Earlier this year we fought a chassis that just wouldn't respond the right way. Sometimes it wouldn't at all and other times it wouldn't enough or even the opposite of what was expected. We got silly and went to extremes to make it do something, anything, but it didn't do anything so we went and got stupid and it went too far the other way. Eventually we carried it out to the scrap pile to be cut up and upon rolling over a buddy found a main rail cracked at the weld, covered up in paint. It ain't going back together in my shop that's for damn sure.
 

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Everyday here too.
Customers are not always forthcoming with info that is needed

Dude brought his 06 silverado with a misfire. Ran bad
P0300 rando multiple misfire
But it also had a p0336 crankshaft sensor signal

After an hour of checking voltage, resistance , continuity on the 3 wires from the CNK sensor to the PCM , I found nothing.
Called him and asked how long it had been acting up. He said , " Well I ran it out of oil 2 months ago and thats when it started acting up".
Sure enough, I then went out and checked crankshaft endplay....Game over .It has .125 thou end play
Thrust bearing is wiped out, letting the crank walk and then the signal is dropping out

This is a 6.0 liter "U" code engine

I could have solved all this in 5 minutes if he had just mentioned what had happened.
His dad was not happy ..

:mad:
 

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Uh........yeaaaaaaaah. i went through it this past summer and pretty much wasted the whole summer. Will provide details soon, but it relates to my thread in the engine section.

But one of the first rabbit holes i went down was:

Smoke billowing out of the right exhaust pipe only (true dual exhaust with no crossover).

i actually took the right side head off thinking it was a blown head gasket and replaced the gasket. Still doing it.

Tried another engine i had in the shed. Same problem. Is this a problem that affects small block chevies? The right side head gasket goes bad???????

Somehow, i had either knocked the vacuum modulator line off/or i did not attach it securely. During another road test i noticed that the trans wasn't shifting right, but there was no more smoke coming out of the exhaust pipe.

It turns out the vacuum modulator was bad---it was allowing trans fluid to leak and be drawn into the intake, and if you look at most SBC intakes, the vacuum connection for the modulator is usually on the right/passenger side of the intake----which likely causes the fluid to eventually go to cylinders 6 and 8, which would cause smoke to come out of the right side exhaust IF you have dual exhaust.

Proper diagnosis is the first step in fixing a car right.
 

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Discussion Starter · #6 ·
Uh........yeaaaaaaaah. i went through it this past summer and pretty much wasted the whole summer. Will provide details soon, but it relates to my thread in the engine section.

But one of the first rabbit holes i went down was:

Smoke billowing out of the right exhaust pipe only (true dual exhaust with no crossover).

i actually took the right side head off thinking it was a blown head gasket and replaced the gasket. Still doing it.

Tried another engine i had in the shed. Same problem. Is this a problem that affects small block chevies? The right side head gasket goes bad???????

Somehow, i had either knocked the vacuum modulator line off/or i did not attach it securely. During another road test i noticed that the trans wasn't shifting right, but there was no more smoke coming out of the exhaust pipe.

It turns out the vacuum modulator was bad---it was allowing trans fluid to leak and be drawn into the intake, and if you look at most SBC intakes, the vacuum connection for the modulator is usually on the right/passenger side of the intake----which likely causes the fluid to eventually go to cylinders 6 and 8, which would cause smoke to come out of the right side exhaust IF you have dual exhaust.

Proper diagnosis is the first step in fixing a car righ
Uh........yeaaaaaaaah. i went through it this past summer and pretty much wasted the whole summer. Will provide details soon, but it relates to my thread in the engine section.

But one of the first rabbit holes i went down was:

Smoke billowing out of the right exhaust pipe only (true dual exhaust with no crossover).

i actually took the right side head off thinking it was a blown head gasket and replaced the gasket. Still doing it.

Tried another engine i had in the shed. Same problem. Is this a problem that affects small block chevies? The right side head gasket goes bad???????

Somehow, i had either knocked the vacuum modulator line off/or i did not attach it securely. During another road test i noticed that the trans wasn't shifting right, but there was no more smoke coming out of the exhaust pipe.

It turns out the vacuum modulator was bad---it was allowing trans fluid to leak and be drawn into the intake, and if you look at most SBC intakes, the vacuum connection for the modulator is usually on the right/passenger side of the intake----which likely causes the fluid to eventually go to cylinders 6 and 8, which would cause smoke to come out of the right side exhaust IF you have dual exhaust.

Proper diagnosis is the first step in fixing a car right.
D.B.....on the bright side....it's great you were able to escape out of that rabbit hole from 1971!
 

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Crap, I was just out riding my Heritage which I refer to as the chrome show. It’s a 2000 last of the carburetors and first of the Twin Cam. So I had replaced the float valve in the carb a few years ago before Covid so it’s been resting for nearly a couple years fuel valve off. This has a Mikuni 45mm slide valve on it feeding a Zippers 98 kit on top the crankcase. Seemed huge 20 years ago.

So I get home and I’m upstairs working in my den late in the evening when I notice I’m getting a sore throat, “crap the damn Covid bug got me”, As an octogenerian my smeller ain’t what it used to be but slowly I come to realize the smell of gasoline. So I go to the garage which is under the house, touch the rubber mat under the bike and it is wet with fuel. I figure that the carb got rebuilt and not used much that it must be something else. Go upstairs to my den and haul out the 2000 manual to start tracing the fuel system and saw there’s an electrically controlled vent valve. Forgetting that long ago it was removed, I start pulling the seat off, disconnecting the tank mounted dash assembly, and prepare to pull the tank.

Well I didn’t quite get the tank removed as I had to disconnect the fuel line from the fuel valve and when I loosened the hose clamp I got a slow but steady fuel drip. Looking more critically at the valve I saw that ever so slightly it wasn’t completely closed.

So I made a big assumption that my earlier work on the carb was still good, and started into fantastical disassembly to chase a problem with a tank vent valve that was removed 20 years ago. Turned out the damned HSR is back to its old tricks and the short term answer is make sure the fuel valve is off, yes the original Harley vacuum operated valve was also removed 20 years ago.

One one hand it’s me on the other it’s back into the HSR again. This being one of many of these type adventures, the lucky strike really two lucky strikes was I wasn’t smoking while cleaning up spilt gasoline and I saw the problem before the bike was reduced to boxes of parts.

A similar thing was 30 years ago I rode my cone shovel rigid to San Diego for my fathers prostrate cancer surgery, just to give mom something else to worry about. With dad home and in recovery for a week I‘m getting ready to head back to Seattle on a Saturday morning. The bike cranks not a full revolution the engine catches then stops and while it cranks it will not restart. So I put it on dads charger and tried again, the engine would crank but not fire. I started down the rabbit hole of a bad ignition module as it gave me fits out in the Mohave a couple years before and this was the replacement to that module. Mom pokes her head out listens to the start attempts and says it’s the battery. I unknowingly become sexist and explain the module which gave me problems previously. She stuck to her guns then went back to tending dad and her kitchen.

A note about mom, she had a degree in music and spent years as a studio backup musician, church organist and grade school music teacher. After retiring at 50 in a few years got bored with being a home maker and in constant musical competition with my father an aerospace engineering manger with a gift for things with keys and strings that mom didn’t have. She was extremely good he was naturally better, I kept this thought to myself. So anyway she went to work at NCR and quickly rose to be an engineering manager for which she had no degree. I pushed all that aside and treated her like a woman and she in here quiet wisdom left me to stew in my juices. After hours on the phone trying to get a module that didn’t seem to be in stock anywhere in southern California. She quitly reminded my that I should load check the battery. Without load it read a nice 12.5. Put a load on it and it dropped to 9 and held for a bit then sank to 7.5.

Crap it’s a weird failure but mom was right the battery is POS. By now all the stores are closed or closing. Turned out Sears has a garden tractor battery that would physically fit so she drove me to Sears we were like the last customer, took it home and put it on dad’s charger overnight this being still lead in liquid sulfuric acid days. Put it in the next morning hit the start button and got Sunday morning loud pipes barking at the rising morning sun. I had a very nice “I told you so” breakfast mom made, happy to see dad getting up and about from his surgery but still facing radiation and chemo in the near future. I lit up the shovel and aimed the front tire north on I-5, put my feet up on the highway pegs, leaned back to let my ears tune into the Sunday morning music of a well running Harley. Now that’s goin’ to church.

Bogie
 

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Uh........yeaaaaaaaah. i went through it this past summer and pretty much wasted the whole summer. Will provide details soon, but it relates to my thread in the engine section.

But one of the first rabbit holes i went down was:

Smoke billowing out of the right exhaust pipe only (true dual exhaust with no crossover).

i actually took the right side head off thinking it was a blown head gasket and replaced the gasket. Still doing it.

Tried another engine i had in the shed. Same problem. Is this a problem that affects small block chevies? The right side head gasket goes bad???????

Somehow, i had either knocked the vacuum modulator line off/or i did not attach it securely. During another road test i noticed that the trans wasn't shifting right, but there was no more smoke coming out of the exhaust pipe.

It turns out the vacuum modulator was bad---it was allowing trans fluid to leak and be drawn into the intake, and if you look at most SBC intakes, the vacuum connection for the modulator is usually on the right/passenger side of the intake----which likely causes the fluid to eventually go to cylinders 6 and 8, which would cause smoke to come out of the right side exhaust IF you have dual exhaust.

Proper diagnosis is the first step in fixing a car right.
I had the same problem years ago on my Blazer! It wasn't until I tore the heads off for new gaskets that I saw the transmission fluid sitting on the number 8 intake valve. After some choice words at myself and the truck I went and got a new modulator too. Whole weekend shot for a five minute fix.
 

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Engines I will no longer run. If you ran one of these you know why. This is my hell no list.

Ford 6.0 (diesel)
Almost any turbocharged Subaru engine.
Ford V10
92-97 LT1
Anything Jaguar
Early NA 6.2 duramax

Hell no for other reasons:

Any transverse V6 that requires the cradel to be dropped for head service. It is more then you think.
Most CVT transmissions
Most 2010 and newer vans
Most "active" suspensions
Anything that has vital lines buried that are plastic when they should be metal. Focus comes to mind.


Several of the above(like the 6.0) you will fix one thing and can easily cause more problems in the process.
 

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1964 Thunderbird, 390 FE
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Engines I will no longer run. If you ran one of these you know why. This is my hell no list.

Ford 6.0 (diesel)
Almost any turbocharged Subaru engine.
Ford V10
92-97 LT1
Anything Jaguar
Early NA 6.2 duramax

Hell no for other reasons:

Any transverse V6 that requires the cradel to be dropped for head service. It is more then you think.
Most CVT transmissions
Most 2010 and newer vans
Most "active" suspensions
Anything that has vital lines buried that are plastic when they should be metal. Focus comes to mind.


Several of the above(like the 6.0) you will fix one thing and can easily cause more problems in the process.
Ford V10 you just take the spark plugs out and put them back in every 5,000 miles and then you don't have to worry about them seizing. Part of the Ford V10 regular maintenance schedule LOL. I think I'm going to do that on my grandma's new (to us) motorhome before we got a problem at 80,000mi...
 

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The above problem i described took about 3 weeks to "solve." i actually took 3 weeks off from work, which in 2006 was about 3K for me which i sacrificed because i was so "hell-bent" on solving the problem, because i wasn't going to "let" the problem "defeat" me.

As for the rabbit hole i went down last summer, this was solved about a month ago when i took it folks who actually know what they are doing----it took them about 15mins to diagnose. See my thread entitled "quadrajet problems" in the engine section.

Note: It had nothing to do with quadrajets; And i'm beginning to resign myself to the fact that i'm likely not an "engine person." i am likely going to pay others to do my engines/tuning for me while i concentrate more on chassis. Not that i'm great at that either, but i'm more comfortable with it.
 

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Race it, Don't rice it!
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There are engines guys, chassis guys, chassis set ups guys and fabricators.
Most do one of those well, the others not so much.
For many, tunnel vision is a real problem wit h troubleshooting and overlooking objectivity.

Yesterday, My dishwasher pump went out so I looked up some parts and pulled it out and changed the pump and cleaned everything and while I was there cleaned out the bottom and spent a while on it. I didn't even make it the first cycle before I knew it still wasn't working right and I tore back into it again. It turned out to be a clogged drain hose. I sucked it out with the shop vacuum and away it goes.
Shoulda checked that first huh?
 

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Another one of my dummy moves was when I built a 350 for my 1977 Chevy Concours. My friend needed a new engine for his Camaro, so I sold and installed one for him and kept his old one. Upon teardown of his core I saw a low mileage rebuild with four spun rod bearings. (He had a lead foot). His block was excellent and I wanted to do an engine on the cheap with some used parts I had laying around. Threw a different crank rods and pistons in it with a new cam and put it in the car. While breaking in the cam I noticed the oil pressure going away. Okay, 10 psi at idle is not good. The oil pump was used so figured that was the culprit. Out came the engine. cut the oil filter and no real glitter to worry about so replaced the oil pump and put engine back in. Okay, better, but not great oil pressure. Took car for a drive and oil pressure started going away and started getting a lower end knock. out comes the engine again. No glitter in filter, so off comes oil pan again. Rods are tight and no spun bearings. WTF? Then it finally dawned on me. I assumed the crank was standard. Upon checking it was actually 0.010" under. WHOOPS! Ever pull a crank with the heads still on? I don't recommend it lol. I gave myself the "dummy of the month" award for that bonehead move.
 
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