starting problem on gasser

[Boatsb]

Never underestimate the stupidity of the previous owner.

 

[UNIQUE_NAME]

I'm trying not to, but looking for logic where none might exist is very time consuming.... it might just be as simple as when they converted to the pertronix they goofed and it worked. wouldn't be the first time we all saw that....

jim

 

[MikeP]

"Never underestimate the stupidity of the previous owner"

This is kinda long but illustrates that point and how troubleshooting can get really painful when you don't know all the facts:

In the mid 70's a friend towed a car to us. He said, "I put in new cap, points, rotor and a condensor and now it won't run." "Fine," I said, we'll sort it out and you can pick it up after work." I assumed it was simply that he installed the points incorrectly (it was pretty common that folks put the point wire on the wrong side of the insulator block) , failed to hook up a wire, or maybe got the wrong (too short) rotor. I checked the distributer - everything was fine but, as he said, it wouldn't start. Cranked fine. Hmmm. I called him at work and asked if he'd done anything else. He said no. Hmmm...I checked everything I could think of in the ign circuit, everything worked fine. Spark at the plugs...NO way it couldn't run!

After several hours on a job I figured would take 5 minutes, I called him back again. "Tell me," I said, "every thing you did, step by step from when you opened the hood until when you brought it here." "I just changed the stuff, like I told you," he pleaded. "No! Tell me EXACTLY what you did - don't leave anything out." "OK," he said. " I opened the hood, removed the distributer cap, then I put the new cap side by the old one and replaced one wire at a time."

"OK so far," I said, "Then what?"

"Well, then I removed the distributer and..." "WAIT A SECOND, I almost yelled at him, "Did you say you REMOVED the distributer?" "Sure, it was easier to work on." "Did you mark the distributer location and rotor position before you removed it?" His response - "Huh?" - gave me the answer to the problem. The ignition was totally out of time with the engine. 10 minutes later it was running fine.

This is perfect example of how you can get totally crossed up by something someone else did that you don't know. If he had brought the car to me saying "it won't run," one of my earliest checks would have been static timing which would have immediately shown the condition. But because he told me he changed the cap, rotor, and points, I was looking for a problem on what he had done and I DIDN"T know about the distributer removal.

I expected the engine to be slightly out of time because he put in new points. But regardless of how bad the initial gap adjustment is when points are installed, the engine timing never gets so badly off that it won't start and run just fine in preparation for adjusting the timing precisely. So it never occurred to me to check the timing initially.

Of course, I learned a lot from this particular experience which is one reason I remember it so vividly!

 

[krush]

Don't know if this was addressed fully, but the "starting circuit" wire usually goes to a post on the starter solenoid that turns hot when the starter is engaged. GM starters have 2 small posts, one comes from the start switch and the other connects to the + side of the coil.

Come on, ya'll should have solved this problem by now. There ain't that many components jk, I'm glad this is a learning experience for ya.

 

[yachtsmanbill]

When I was a KID, I had a 67 Mustang that I put a 4 barrel manifold on. Did a COMPLETE tune, of course, and couldnt get the SOB to run right, like REALLY BAD. Had several pals look at it, and even confirmed that the wires were in the correct order, only counter clockwise. Eschew obfuscation. ws

 

[captddis]

You may be looking for a wire that is not there. CC did not use the bypass wire on those engines. They came with a internal resistor coil. There was a kit later to add the bypass. I changed a lot of them over back in the day.
Dave

 

[UNIQUE_NAME]

sorry for the time between posts, was away this week and just returned. went to boat this morning.
here is the latest in the saga. had a helper today so i pulled the cap and cranked to observe the rotor. it will spin abut 1/4 turn when then stop, spin a little stop again and so on during cranking. pulled the rotor and trigger and can rotate the cam with pliers. this seems like a design flaw . i have to smile otherwise i'ld cry. this would explain why i sometimes had intermitant spark.
so at this point i have a new pretronix II installed, new cap/rotor/coil and balast resister anlong with all connections being triple checked.
anyway, the dist must come out. if the dist shaft is cracked, will the gear come with it when i pull it out? if not, any tricks on how to get it out? any other ideas on what this might be symptoms of?

jim

 

[captddis]

No it isn't cracked. All you need is either a new advance plate/ cam assy or either solder the cam to the plate or use some loctite or equiv. The cam is just peened over on the bottom and they work loose .The other option is to take the dist to be rebuilt. All the parts are available from Mallory and it is not hard to DIY.

 

[UNIQUE_NAME]

how is the cam attached to the main shaft?

 

[captddis]

It isnt attached. It sits over the shaft with a retainer clip and is spun by the flyweights . The advance plate is attached to the shaft. Dave

 

[yachtsmanbill]

Pull the distributor and check the roll pin that holds the gear on... that gear also drives the oil pump and can shear. Also a brain fart... Pull a valve cover and crank to make sure the valves are all doing their thing. Could be a busted PLASTIC cam gear (?) ws

 

[UNIQUE_NAME]

i can put the rotor on and rotate the cam and plate by hand. another design flaw. sounds like the pin on the gear?

jim

 

[MikeP]

AHA! Some things are never as they seem!


I can't imagine the dist shaft is cracked but having an intermittent spinning of the rotor certainly indicates that either the roll pin that Bill mentioned or the gear on the dist shaft itself has failed.

The gear should come out when you pull the distributer. If the pin has failed, the gear will still be on the shaft and should come out with no problem. If the gear itself has failed - no telling - you will have some of the gear still on the shaft and possible other parts of it...elsewhere. Note that if ANYTHING has failed - pin or gear, there may be bits and pieces - hopefully (and probably) in the oil pan where they can't hurt anything anyway.

The other possibility is, as mentioned, a failure of the cam gear itself. This seems unlikely but it is possible. As Bill stated, watching the rocker arms go up and down will tell you if that has happened. You might as well do that first because if that happened, the distributer itself is likely OK.

In any case, since the distributer rotor hasn't been turning properly, the engine is now totally out of time with the ignition no matter what happens from this point on (whether you put in a new dist or not) so you have to set it up statically. I apologize if you know all this...

The firing order for a GM v8 of the era used for these engines is 18436572. The cylinders on the engine are numbered 1357 (front to rear) on the left AS YOU FACE IN THE SAME DIRECTION AS THE ENGINE and 2468 (From front to rear) on the right. Check the service manual to ensure this is correct. Fairly recently, GM changed the firing order but it should not affect your engine. The dist cap will probably show a #1 next to one of the terminals. This is where the spark plug lead to the #1 cylinder attaches. If it doesn't show #1, it doesn't matter, put #1 wherever you want it! The rotor in the dist spins clockwise so following #1, the rest of the sparkplug leads attach to the cap clockwise in their firing order.

Before you put the dist back in, rotate the engine so that #1 cylinder is coming up on the compression stroke - you can determine this by removing the spark plug, placing your thumb over the hole, and having someone rotate the engine clockwise AS YOU FACE THE FRONT OF THE ENGINE with a breaker bar and socket on the harmonic balancer bolt. As you feel pressure on your thumb, you are on the compression stroke. Rotate the engine so the timing mark on the balancer is at the 5 degree mark before top dead center on the timing tab. This will be close enough for now.

Observe where the dist cap will fit on the dist - note where the #1 spark plug terminal will be in relation to the distributer housing - put a mark on the side of the dist housing. Put the dist rotor on the shaft. When you lower the dist into the engine, arrange for the rotor to point at the mark you made on the dist. This means that when you put the cap on, the timing will be in the ballpark - close enough to start and run well enough to actually adjust the timing to spec (as found in the service manual) with a light.

Let us know what you actually find!!!!

Good Luck and best wishes for a CHEAP repair!

 

[yachtsmanbill]

Yer showin yer whiskers Mike !! My gas boats' 454s, being counter rotating use the standard rotation engine on the port side; This is where it gets confusing: WITH a timing chain. The starboard side has a gear drive for the UN OBVIOUS reason. The crank needs to spin opposite. but the CAM needs to spin correct to drive the oil pump. The distributors both turn clockwise.
It got even worse on the 283F's (flywheel forward) where as the rotation thing was reversed as the trans bolted to the front of the engine which was installed backwards. There was a cable tach drive to run the oil pump, but a ChrisCraft front housing for a FOMOCO distributor. Those F's had red headed daddies !! The standard 454 rotation is 18436572 but the opposite is 12756348, the cams are the same believe it or not and the cranks are too, but the O.R. crank has and extra key for the damper and timing gears. One will work in the other, but the other wont work in the one. ... And LSD is illegal???
WHEW ! had to let the carpal tunnel cool down after that one ! I think that generally, if the pin shears, all three pcs. should come up with the unit. If the gear shattered, its a magnet job (cast iron gear).I think any debris will fall straight down to the pan from there.
At worst, could be a broken camshaft also. Enough drag on the cracks to roughly spin the sparker. The oil pump can actually take as much as 5 horse power to spin at speed / pressure. Remember when blowers were the rage? 200 horse power, but a hundred of that was turning the huffer at 6000 rpm.
If memory serves me, isnt the points cam pinned as well? That has the advance unit UNDER the points plate. If the points plate spins , that lost the 2 mounting screws. It should turn with the dist. frame for timing purposes.
Hopefully the worst is a broken nylon cam gear. Remember those 389 ponchos?? I'm sure youve been there !! ws

 

[UNIQUE_NAME]

thanks guys. at least i have a plan of attack. i'll pull a cover and check the valve action, but i doubt the cam gear is plastic. the motors are 427 chris craft fords. i'll post the gory details later.

thanks,

jim

 

[yachtsmanbill]

thanks guys. at least i have a plan of attack. i'll pull a cover and check the valve action, but i doubt the cam gear is plastic. the motors are 427 chris craft fords. i'll post the gory details later.

thanks,

jim

AHA !! You didnt mention those were the side oilers. Now the COBRA/SHELBY boys hafta take over !! LOL
(a pal had those in a '68 steel Roamer and as a matter of fact DID break a camshaft !) ws

 

[UNIQUE_NAME]

(a pal had those in a '68 steel Roamer and as a matter of fact DID break a camshaft !) ws

i liked the other diagnosis better...

jim

 

[captddis]

The F engines were flywheel aft. the plain 283H or M was flywheel fwd as were the Q engines.
The problem is the dist plate. the cam is slipping on the plate!!!! I have fixed dozens of these. Don't look for complicated problems that are not there. The 427 Ford had steel timing gears and a double chain.

 

[yachtsmanbill]

AHA !! You didnt mention those were the side oilers. Now the COBRA/SHELBY boys hafta take over !! LOL
(a pal had those in a '68 steel Roamer and as a matter of fact DID break a camshaft !) ws

When you do the valve check, make sure that everything is turning in unison ! Kinda like doing the valve setting routine. TDC on number one and you can set 4 intakes and 4 exhausts. One revolution to tdc again and you can set all the others. (its in the book on setting solids) After that, check the rotor position. ws

 

[UNIQUE_NAME]

The F engines were flywheel aft. the plain 283H or M was flywheel fwd as were the Q engines.
The problem is the dist plate. the cam is slipping on the plate!!!! I have fixed dozens of these. Don't look for complicated problems that are not there. The 427 Ford had steel timing gears and a double chain.

but i can put a rotor on and hand spin it watching the cam and plate make a full 360 revolution. if the cam was slipping wouldn't the plate remain fixed?

jim