Great now what? Engine won't stay running.

[mchandford]

I have been tweaking with the car for a while now. Little things here and there. Changed timing, and air screws. I previously cleaned the carb out and reinstalled. It seemed to be running pretty well. It has only been a couple weeks since I started the car, but about a week ago I changed the spark plugs to new ones. I did change the gap a little, from what was in it before at .042 to .035 (which should be stock). I went out to the car today because I got off work early. Click-click. Wouldn't turn over. Dang battery is dead. So I jumped it. Got it running, just barely, tweaked the idle up a little so I could get out of the car to get the cables off without it dying. I actually had to roll the car out of the storage unit which was scary. Then I was afraid I wouldn't be able to get it back in. But it started finally, limped it back into the unit, kept it running for about 10 minutes. I tweaked the air screws again, this time about 1 1/2 turns out from the 1 turn out it was at. idle was still sitting about 900, not too high. but I think it is blowing out smoke now. I am not sure if I made the rich condition worse with the new plugs and that is the smoke i am seeing, unburnt fuel, or if something else is going on. Please someone give me some advice.

 

[mustang7173]

mchandford,

What kind of carburetor are you running? How old is it? I have gotten used Holley's that I have rebuilt and rebuilt. Some I got to run good and some not so good. One problem with the Holley's or any other used carburetors, is the the heat and cold will eventually cause internal cracks inside the main body. Not much you can done about, other that get a new carburetor. Also, are you using a vacuum gauge when you are tuning the timing and adjusting the fuel air mixtures? Need one to really dial it in! Also, some late carburetors had reversed fuel and air idle screws. Make sure there are no vacuum leaks too! If you have the vacuum advance type distributor, check the vacuum can. It could be defective.

mustang7173

 

[mchandford]

mchandford,

What kind of carburetor are you running? How old is it? I have gotten used Holley's that I have rebuilt and rebuilt. Some I got to run good and some not so good. One problem with the Holley's or any other used carburetors, is the the heat and cold will eventually cause internal cracks inside the main body. Not much you can done about, other that get a new carburetor. Also, are you using a vacuum gauge when you are tuning the timing and adjusting the fuel air mixtures? Need one to really dial it in! Also, some late carburetors had reversed fuel and air idle screws. Make sure there are no vacuum leaks too! If you have the vacuum advance type distributor, check the vacuum can. It could be defective.

mustang7173

It seems like I've already been down this road. I am running an Edelbrock 600cfm. Everything looked really clean when I took it apart, it was a hail-mary. Didn't change anything. But before the spark plugs changed it was running smooth and seemed good. One of the chiefs I work with said maybe the fuel is bad already. It has only been in the car maybe 2 months. It was super-non ethanol, but could it have gone that bad this quickly?

Vacuum gage yes. It was kind of strange because the advance/timing that gave me the most vacuum was not the smoothest idle. I had to come back about 5 degrees to get the idle to smooth out. Distributor seems to be operating properly. It might be doing something funky at higher RPMs, but i'm not even at that point yet. I'm just trying to get it to idle properly. Lots of fumes, bad smell, not pleasant to be in the unit when the car is running.

 

[Jeff73Mach1]

Also go ahead and test your ignition system and coil too. A weak ignition can cause problems. Are any wires crossed up of not firmly seated? Often removing plug wires will damage the wires. A meter testing continuity of wires will help identify a damaged wire(s)

 

[mchandford]

Also go ahead and test your ignition system and coil too. A weak ignition can cause problems. Are any wires crossed up of not firmly seated? Often removing plug wires will damage the wires. A meter testing continuity of wires will help identify a damaged wire(s)

that is something I haven't done. How would I test the coil and ignition? Remove a plug turn over and test for spark? I can check continuity, thats easy. But how do I know if the spark is just too weak?

 

[Jeff73Mach1]

easy way is to unhook the coil lead to the distributor and ground it and the coil wire to look for sparks. They won't be huge, but should be pretty noticeable in dim light. here is a video for a points system, the test is the same for HEI or Duraspark etc, but the voltage is about 4 time as high so just wear a nonconductive glove



idle adjustment screws can screw up your mixture, but if turned all the way in and then 1 1/2 turn out they should be close enough to do better than you described.

Ignition problems often occur after pulling wires loose, always use care and dielectric grease!

 

[caspianwendell]

easy way is to unhook the coil lead to the distributor and ground it and the coil wire to look for sparks. They won't be huge, but should be pretty noticeable in dim light. here is a video for a points system, the test is the same for HEI or Duraspark etc, but the voltage is about 4 time as high so just wear a nonconductive glove

More like 3 1/2 turns to start

 

[Jeff73Mach1]

you may be right I forgot that it was a Carter AFB . . . I mean an Edelbrock lol

 

[caspianwendell]

you may be right I forgot that it was a Carter AFB . . . I mean an Edelbrock lol

LOL...all true

 

[mchandford]

Cool, so I should be able to test the coil this weekend. Dielectric grease!!! Dang it! Wish you guys had told me that before. Could that be the problem, or is that just going to keep me from tearing the wires up in the future? Never had to use it before so this will be good learning i guess.

Someone please describe best practices for removing/replacing spark plugs. Then I can tell what I did wrong.

I still need to test the wires now to see if I broke one. They seem sturdy, but I did have to yank on a couple of them to get them to come loose.

3 1/2 turns on the screws is about where I am getting it to run the best.

Any other ideas much appreciated. i really need to have the car ready to go in about 2 weeks. She is getting loaded up on a truck and shipped across the state of Washington. Headed to the new home. This time should be for good. I have 10 more years in the Navy and we are trying to do the rest of them in the same place.

 

[wwhite72]

Lots of fumes, bad smell, tough to get idle adjustment? Sounds like an intake manifold leak. Mustang7173 mentioned above to look for vac leak, i would agree. If you had a Holley id say it could be a blown power valve, but since edelbrocks dont have power valves its gotta be an intake manifold vac leak. I didnt see what engine you have but i know the Clevelands sometimes have trouble sealing the pan gasket. I took mine out, used new Fel-pro and a thick bead of silicone. Still have had an occassional leak which my be due to the alum intake, or the CHI heads not having a perfect match. But this has been a problem in the past. You can try cork style, or the fancy blue silicone type, or bust your wallet on a set of Cometic stainless sandwich style gaskets. But either way you gotta keep that intake manifold on there air tight. After you do that everything else starts to work properly.


Oh, and for the few dollars it costs, might as well get a new and CORRECT sized PCV valve. They do get stuck, and you would be surprised how often he wrong one is on the engine. Its only a couple bucks.


Oh, and for the few dollars it costs, might as well get a new and CORRECT sized PCV valve. They do get stuck, and you would be surprised how often he wrong one is on the engine. Its only a couple bucks.

 

[mchandford]

If it was a vacuum leak like that, wouldn't it be running lean? It is definitely not running lean. Someone else had mentioned that if you can get the car to stay running when you put the idle screws all the way in you have a vacuum leak. Mine definitely will not stay running. I can use some of the tricks you guys have used to look for leaks though. It is worth a double check.

 

[wwhite72]

an intake leak can in some cases allow a bit of oil into the cylinders causing the smoke or smell. i have had it happen on my 351C. it will also make it tougher to get a smooth idle adjustment.

 

[mchandford]

an intake leak can in some cases allow a bit of oil into the cylinders causing the smoke or smell. i have had it happen on my 351C. it will also make it tougher to get a smooth idle adjustment.

hmmm, oil would make sense too. Dang it. So how do I tell if there is oil getting into the cylinders?

 

[wwhite72]

DMV will tell you if you go for an inspection! heh heh. i have heard a few ways to check for a intake leak. some guys say they can hear it. my engine is kinda loud so i cannot. some feel around for gaps, some look for gaps. got any oil under your car, or dripping down the back? probably some guys here smarter than me would have some suggestions.

 

[mchandford]

ya, no oil on the ground. I had noticed the seal around the intake looks damp in a couple places. I guess that would be a good place to start.

 

[wwhite72]

you have a 71 Cleveland and there is an Edelbrock carb on it? sounds like there's a chance the intake has been off at some point. Whether it's a matching alum edelbrock or a iron OEM intake, if you decide to change the gasket i would consider buying new ARP bolts as part of the re-install and be sure to check the torque spec and correct order! you can screw up a gasket set if you move the intake around at all once you drop it on, or torque in the wrong sequence, and then you are back where you started. ever see an engine with big black globs of RTV across the front? you dont want that. and then check that ALL the vac hoses are not cracked and back where they are supposed to be (correct port on carb to dist) and the pcv and the passnger side valve cover breather hooked to the cleaner housing etc etc. i dont recall ever messing with the air screws on my holley. but i did originally have the funny dashpot that was hooked to a transmission sensor to prevent engine run on. that got tossed pretty quick.

 

[hyena429]

you have a 71 Cleveland and there is an Edelbrock carb on it? sounds like there's a chance the intake has been off at some point.

1+ to that...Cleveland intakes love to leak ...You have to be generous with the silicone when putting them on...First time i did mine...I thought i put plenty on it....was using nice felpro gaskets and everything....Well it was a big mess up...Had to take it back off...And i could see so plainly that the gaskets and silicone i put on was not enough and it would of leaked like crazy...i put plenty in corners "what i thought was plenty" Nope..Not enough...If your still having issues...i would just pull the intake and look for troubles....I used the most hated cork gaskets on the front last time i did it...Cause they just took up more room and i could use little less silicone around it...But still...i laided a bead about the size of my pinky around that sucker...hardly any of it squished out...looked clean...one spot in front it did a little..i cleaned it with a rag before it dried...sealed up like a dream.

It could just be barely leaking some where and giving you all sorts of little issues...That is could

 

[Don C]

I agree, Cleveland intakes are difficult to get to seal. One of the problems is getting them on perfectly even. If they are sitting at the slightest angle they will leak. One thing that helps is to put four studs in the center bolt holes, next to the carburetor base, to help align everything. Then, make sure the torque spec you are using matches the manifold type, aluminum Edelbrock manifolds are different than the iron manifolds. Then torque them down in at least three stages.