300 I6 not running.. Sunday night chat crew

[Anthony]

OK, you guys were wanting a compression check and every cylinder is between 175-180... so I don't have a compression problem... this has to be simple... I will be back on Sunday night for more help.. thanks guys any way possible that my 600cfm carb is too big for my .060 over 300 six? getting too much fuel? it ran to Iowa with it? looks like I might be pulling the valve cover to watch the rockers and see if I wiped a lobe or two

[LM14]

The 600 worked fine for all those miles to Iowa and the other carb you put on didn't help. You've changed the ignition system, plugs, wires, carb and have good compression.

Did you get to check the timing?

How about the dwell with a dwell meter?

My guess is cam lobe or rocker issue.

SPark

[Toyz]

I missed the conversations, so I may be missing the issue. I wouldn't expect cam lobe or rocker problems to result in a "no-start". Such problems most likely would affect cranking compression readings also.
I tend to agree with Steve, a full range of ignition/ timing checks may be helpful. As usual, that old "ground" issue tends to pop up in these matters. It is not unheard of to have a defective new condenser either.
Paul

[Toyz]

300s also have a history of stripped distributor drives. If you haven't already, might be worth checking to affirm that number one timing is not moving from original position, although back fires should result in that case.
Paul

[slick4x4]

Cam gear or ignition... My guess

And be sure that gas is being pumped to carb

[aarons428]

How about rockers being to tight and holding valves open??

[Nathan390]

He has compression.. so its doubtful that its cam rocker related.

First check.. is there spark?
Second check.. is the fuel coming from carb?

If you have both of those then its a timing issue..

If it was cam gear you would think the compression would be effected or affected.. but it would be all cylinders.


I never saw a post or comment saying it was back firing so I'm guess no voltage to or through the distributor.

[bobenhotep]

I was in the Sunday chat session. He can get it to run and then it has fouled plugs, if I remember correctly. The impression I got was that he has a weak spark, but I am not an expert on Kettering ignition, I am an electronic ignition guy.

Dan

[LM14]

He said it started but ran very rough. Couldn't keep it running long enough to get a dwell or timing reading. Said it takes gas when you open up the carb but doesn't accelerate the engine. From his description I first thought a coil or retarded timing.

He has replaced the fuel system and ignition system. I do not know if the replacement parts were brand new or ones taken from something else.

No backfires were mentioned.

This is a freshly rebuilt engine that was broken in for a week or 2 and then driven to Iowa for SS and back home. It started acting up on the way home and got worse until it reached it's present state. It hasn't been drivable since he got home from SS.

SPark

[bruceandersson]

One of the tricks I use to set the dwell is to take the plugs out, and check/set the dwell w/o the engine running just using the starter. What type of carb are you using? I had fits trying to get the 390 CFM Holley running on my 300, I finally swapped it with a 500 CFM Edelbrock and it runs fine. If your floats are off, it can cause a rich condition and you can see the extra gas coming in from the top of the carb.

[Toyz]

Cranking dwell check can be a good diagnostic tool for dwell variations, or for a vehicle suspected of having a worn timing chain. The original cam gear on the LD 300 was fiber; i wouldexpect the rebuild to utilize a metal gear.
As has been stated, lack of backfiring would lead me to carefully check ignition related problems first, regardless of the newness of parts.
Paul

[ICEMAN6166]

you can get the gear in both nylon and steel, i prefer steel some folks use nylon because they say its quieter, personally that is not a convincing reason.

if the plugs are getting fouled then the spark is not hot enough to burn the fuel or there is too much fuel to burn.there is also the issue of possible bad gas.

[unibody madness]

Check the grounding wire inside the distributor. I use the petronics and had a similar problem, they sent a list and that was on it, fired right up

[banjopicker66]

Sorry to be late in this thread, Anthony, but I spent the last few days in the hospital for chemotherapy related issues.
My gut feeling still tells me this is ignition related, but rocker issues might mimic some of this as well.
I suspect first of all the condenser has gone bad. Some will come bad new out of the box, so this isn't that unusual. Try replacing that first, it is cheap and easy enough.
Also, have you checked the points? For excessive burning or slipping from a loose screw? Also, to make sure you have a good gap starting point for the dwell? I seem to recall that a 0.20 gap with a feeler gauge is a good place to start, but have read online that 0.27 is factory specs. (Keep in mind that changing the dwell also changes the ignition timing, but that can be worked with, and might even get the truck running again, enough to get all the settings correct.) Too large or too small a gap will cause ignition problems also.

Second, the way it ran well, then began to run poorly, then just ran out of power seems to me that something is slipping out of adjustment. One possible cause is the distributor hold down bolt is loose, so the distributor "walked" a bit, throwing off the timing. Another one is a stripped distributor gear shear pin, or wiped gear teeth.

Have you tried to alter the timing by moving the distributor itself by just a few degrees? Be sure to mark the existing location, then advance it a bit. (Advance the timing by rotating the distributor body opposite the direction the rotor turns.) You won't hurt anything this way, and if this method gets it running, you can time it properly. If advancing it won't get it started, try retarding the timing by moving the distributor body the same direction the rotor turns.

I hope this helps, and best of luck finding and fixing the problem.

[joefordtruckf250]

Second the condenser. Brand new one from Autozone in my 240 Inline went bad. replaced it with one I found in my basement, and now runs great. AutoZone one was intermitant. Seems to get hot and stop working like a bad coil would.

[Anthony]

I have tried i all guys... new points, condenser, dizzy, fuel pump, carb, ect...ect... I have set the timing and it still wont run but just spit and sputter... my mechanic said to bring it to him and he will get it right for me... he does me well on price so she will be loaded tomorrow and off to a real Dr. and not and away from this back yard medicine man... thanks for all the replies and help guys but I am just not a "real" mechanic.. but I will try it till I can't get it to run.. oh yea, I'm there..

[aarons428]

Its time for a BIG BLOCK!!!!!