Very Frustrated - Engine Problems!
 

Alright, I'm not "mechanic enough" to fix this even with advice ... but I gotta vent a little...

Twice this week I had a short, intermittant problem while driving my Cobra. I'd be crusing along in 3rd or 4th and all the sudden, the car would start to stagger and stumble under any attempt to accelerate. First time it happened, I immediately pulled over to the side of the road got out to look around and it just "fixed itself". Continued driving with no problem. Second time it happened, I engaged the clutch and could rev the engine just fine but could not accelerate in gear. Didn't pull over that time, it again just fixed itself while driving. Both times this was on a flat highway, straightaway at normal cruising speeds. Yesterday I drove down to an Atlanta Cobra meet and had absolutely no problems at all.

Today I was crawling under the Cobra tightening up the header bolts (found one missing again that I replaced, this time #1 top) in preparation for the car's introduction to the family during Thanksgiving. I was feeling very proud of myself because I finally figured out all the body contortions to reach all of the bolts, so I decided to go for a quick drive. Well, about three miles out the stumbling and hesitating started again ... only this time it didn't just go away and I limped all the way home. Same problems and symptoms as before. It took me three times to try to get up the hill in my driveway with all the neighbors look on. Very embarassing!

Any ideas???

Jason

PS. I know that Bill at SA will definitely fix me up right, just not very happy right now!

Jason;
Do you see any black smoke coming out of the exhaust when you are haveing trouble? When it starts to stumble can you clutch it and rev up the engine? What speed are you trying to accelerate from and in what gear?

Poorboy

I think what poorboy's looking for is a sticking float. :rolleyes: Have you checked what the spark plugs look like after an "episode?"

Poorboy

I have noticed some black exhaust from the pipes lately .. didn't notice it during the stumbling, but could have been there.

When it stumbles, I CAN clutch and rev the engine. Usually I've slowed down (in fear) and regardless of what gear I put it back into it starts stumbling again. The first two times I was on the highway at around 75mph in 3rd or 4th. Today I was pulling out of a parking lot to merge while in first. It happens while both trying to gradually accelerate and hard accelerate. It REALLY doesn't like to try to hard accelerate when stumbling, so stopped trying that.

Also if it helps, I have had 3x times this week when during starting there's a bang and smoke coming from under the hood. When I pull the hood up expecting the worse, the smoke is around the carb and clears quickly. Runs fine after that.

One other thing I did today was to reduce the idle. Was idling at 1100 and dropped it to 800/900. The original two times happened at the higher idle, but today happened at the lower idle. Maybe I should raise it again.

Thanks for your patience. I'm very excited, trying to learn, and very frustrated at the same time.

Jason

Bob

Thanks. I have not checked the plugs. Honestly, would not know how to "read" them ... and being severely color blind may not help either! :JEKYLHYDE

I bought a Holley book from HPBooks (4th Ed) yesterday. Reading that as we speak.

Jason

argh ... won't start.

Take off the air cleaner, look down into the carb....is there lots of raw gasoline there?

Take out one spark plug....look at the part that goes into the cylinder head....you can be color blind to see if there is a problem here...is it all black and sooty? Does it smell like gasoline?:)

Boy it's nice having a wireless network ... got the laptop going "Cobra-side".

Pulled the air cleaner. No gasoline sitting on the throttle (correct term?). When I pushed the accelerator linkage, the front throttles opened and gas sprayed into them. Couldn't see any "standing" gas through the throttle.

Jason

Patrija;
Sounds like you have a blown power valve, possible other carb trouble. Looks like another trip to see Bill or Luis.

Poorboy

Would a blown power valve prevent the car from starting? I have a local place I am going to try to bring the car to tomorrow, but need to get it started unless I am going to put it on a flatbed.

Thanks
Jason

OK - put the air cleaner back on.

What kind of ignition system do you have?

Grab hold of the distributor and see if you can turn it - you shouldn't be able to.

Pull the distributor cap off and just look around inside the distributor - If you can identify the rotor, look at the brass piece on it. See if it moves in any direction. It shouldn't.

- I realize you said you don't know anything about this stuff, but just go slow.

And no, it should still start with a blown power valve.

if you have a friend who is handy to help you you may want to try pulling off your carb. Take off the float bowls and BLOW them out with a hefty dose of carb cleaner. Also, shoot it down the float adjustment screw holes. you could blast those holes with the carb mounted but if it is dirt you may just lodge it in the metering block. If you have the metering blocks off, hold them out in a well vented area and blast all the orifices with the carb cleaner. Of course, use the spaghetti hose at all times. If you have dirt in your carb that could cause intermittant opening or blockage of the needle/seat which would drown your motor .
You could have a dirt particle floating around your bowls which sometimes lodges in the metering block. Replace all your carb gaskets (4) plus the bottom plate gasket) before reassembly. You could "check" your power valve but for ten bucks it is almost worth just replacing it. Overall your buddy may spend 45 minutes or so and a few bucks but hopefullly you will have resolved the problem. It is a worthwhile effort that could save you money.
It just sounds like a minor carb problem that erupts to cause all the havoc. If it is a Holley, dump the stone filters and install an inline . Do you have a carb shop nearby ? They may blow it out for you. Again, as stated by others above, I am also just "assuming" it may be the carb from your description of events.

I'm back now ... wife had me working on the house for a bit.

I pulled the #4 plug. It is BLACK and definitely smells like gas/exhaust. And that means???

For ignition, I have an MSD 6A box.

Thanks everyone for your help and patience!!!!

Jason

One more question -what kind of distributor do you have?

The plug smelling like gas means one of two things - either the carb is screwing up or the ignition is.

;)

Did you take the distributor cap off yet?

Alright, I'm an idiot .. I admit it.

The distributor is the round assembly in front of the block right? If so, not sure what kind it is. All the spark wires are ACCEL. I checked all of the wires to the distributor (round assembly?) and they are tight.

BTW, I owe you a beer :3DSMILE:

Jason

Assuming the round assembly is the distributor, I can't turn it but it does move approx 1/4" left to right.

Also, wanted to make sure that is the right piece before I try to remove it! :-)

Jason

OK, assuming it's the round assembly (think I confimed that on the holley website), I removed the black pastic cap. It was held on by two metal clips.

I couldn't find a brass piece. The rotor turns about 1/2" counter clockwise.

>> OK ... removed the plastic piece on top of the rotor, and under it was the brass piece. The rotor turns about 1/2" ccw, but the brass piece does NOT turn with it.

Took two pics if the help.