Help, I Screwed Up

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EdM

Well-known member
Joined
Jun 5, 2014
Messages
578
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24
Location
Between the Texas Hill Country and North Idaho
My Car
1973 Mach 1 Q code, a 427 Dart based Windsor, Pro Flo 4, Tremec 5 speed, A/C, 12.7:1 steering conversion, SoT coil over and Dakota Digital dash.
The car has been up on the lift for close to a week so I thought I would drop it and run it a bit. The hood was cracked open (which should have clued me in) so I got in and attempted to start it. It barked, stumbled and blew an azzload of grey smoke, fuel. I stopped and realized I had the air cleaner off and a clean rag over the carburetor inlet. I installed the air cleaner and took it out for a ride. The exhaust seemed to clean up but as soon as I tried to accelerate it coughed, tach diving to zero with zero power, bounce up, bark, drop again. I am assuming carb? Blown power valve? Help please. As always, appreciated in advance.

 
So to get this straight, someone else is working on your car, and without consulting them you hoped in and decided to take it for a drive. Maybe talk with them and see what they did?

 
No one has worked on my car. My lift and it was driving great last time out.

 
Ah I see, from the way I first read it it seemed otherwise, my fault! Had you made sure the linkages are all free? I have had problems with the secondaries freezing up on my before

 
So was the clean rag gone? Did it get sucked in or ?? A worse case scenario is the rag held a valve open (most likely the intake) and a piston hit it.

At this point a compression test is in order. Don't run the engine anymore. Check the oil for coolent. Again, this is all worse case. I am sorry this happened to you.

 
From what I've read, there was a shop rag draped over the carb (no air cleaner) and when the engine started the rag pretty much blocked the air horn inlet. I find it extremely unlikely for the rag to get past the upper butterflies and lower butterflies in the carb to do any internal damage. (Well, maybe if it was tissue paper that got shredded).

What kind of carb?

It's possible due to the intake pressure. a portion of the rag may have bent something slightly (i.e. linkage) - but also unlikely. Did the idle smooth out at any time? Need a little more information.

 
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I gotta agree with Bill - hard to imagine the carb allowing a shop rag to get sucked in past the butterflies.

Without the PCV circuit hooked up, and without proper ventilation for the PCV system, some oil could've found a way to sneak into the combustion chambers (through weak valve seals) and fouled a plug or two... or it could be as simple as something forgotten to be connected back up causing your problems.

Start with the small stuff first.

  • pull the plugs - they'll tell you a lot
  • check the distributor cap & rotor
  • ensure timing is still where it should be
  • check all vacuum lines for proper connections
  • check all under-hood electrical connections
  • check the spark plug & coil wiring
  • check the fuel filter(s) for flow
  • check proper carb functionality (including linkage)


It sounds like something is either disconnected or gummed up - disconnected vacuum lines are the worst for this.

 
Appreciate the replies. The rag was laying rather loosely on the throttle body and was found the same when I realized what I had done. The PCV circuit was functional, a filtered breather on one valve cover and an M/E Wagner PCV valve dialed in on the other. I will work Mister 4x4's list and see what I find.

 
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.

if the power valve is bad, it will idle rough and may still idle if you turn the fuel ix screws all the way in.

set the float level so the gas is just below the inspection holes with the engine idling or immediately after you turn it off.

look in the front carb venturis then slowly open the throttle 1/8th . . you should see two strong streams of gas shoot out.

disconnect and plug the distributor vacuum hose until the prob is fixed.

.

 
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Okay so it wasn't sucked into the Throttle body?
Sorry for the late reply. I have been out of town touring a college with my son for next year. It is very doubtful that anything got sucked into the throttle body. The "rag" was actually a very heavy/dense cloth diaper left over from the days of my now 24 and 26 year old's. No frays in it, just solid, tight (as you can imagine:D) and not frangible. I checked all vacuum lines and all is good. I just pulled all of the plugs and #'s 3, 4, 7 and 8 are very fouled. The rest look great. Thoughts?

 
When you said "on the lift," did the car have front lifted higher than the rear? Plugs 3, 4, 7, & 8 are the rearward cylinders, having the front inclined would put the task of oil returning to the oil pan on the rearward oil passages, which would cause the oil to sit longer... if you have old or starting to leak valve seals, some would flow into the combustion chambers, overwhelm the spark plugs, and now they're fouled.

I would clean up and re-gap the plugs (or get new ones), make sure your ignition system is working properly (timing, points - if you have them - gapped and timed properly, new cap & rotor, wires, etc.), and go from there, checking for the use of oil (blue smoke) under normal operating conditions.

If you're puffing blue smoke 'normally' at start-up, it's time for new valve seals and/or rings.

Fellas - comments?

 
My Jeep does this periodically, and I have to pull the fouled plugs to clean them, then everything's fine. The engine has a slight decline to the rear because of the lift kit (drop-kit for the skid plate/transmission mount), and 4-5-6 are usually the ones that are the ickiest. I'm sure it needs new valve seals after only 135K miles.

It also tends to have a hard start-up and eventually smooth out with bad gas, too. Stay-Bil has been helping in that area, though.

 
The diaper draped over the air horn resulted in a total choke situation. Clean the plugs and run it again.

However, the observation that 3-8 were very fouled may indicate you may have oil leaking into the cylinders thru the seals or a very rich condition.

 
When you said "on the lift," did the car have front lifted higher than the rear? No, level lift. Plugs 3, 4, 7, & 8 are the rearward cylinders, having the front inclined would put the task of oil returning to the oil pan on the rearward oil passages, which would cause the oil to sit longer... if you have old or starting to leak valve seals, some would flow into the combustion chambers, overwhelm the spark plugs, and now they're fouled.

I would clean up and re-gap the plugs (or get new ones), make sure your ignition system is working properly (timing, points - if you have them - gapped and timed properly, new cap & rotor, wires, etc.), and go from there, checking for the use of oil (blue smoke) under normal operating conditions. My thoughts as well. I have never had an issue with oil usage/blue smoke.

If you're puffing blue smoke 'normally' at start-up, it's time for new valve seals and/or rings. I do not have this condition. The engine was rebuilt 6k ago.

Fellas - comments?
Appreciate the reply. I am heading to Arizona for a camp and shoot fest and will attack the plugs on Tuesday when I return.

 
I got the Autolite 25's in and the car is running better than ever. So, yes, fouled a few plugs towards the rear.

 
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