carb issue and timing help

[Anonymous]

I have two problems. First, when my '66 mustang with a straight 6, 200cu gets hot and I'm driving under stop and go conditions the engine starts to idle rough and eventually when it gets hot enough stalls out. I can keep the engine running in park if I hang on the accelerator, but when I put it in gear it stalls out. I do not have this problem when the engine is cold or moderate and no problems on the highway. Someone suggested to me that it might be a vaccuum hose problem. Anybody have an idea.

Second, when I set the timing to the specs on the valve cover the engine runs rough. It's supposed to be a 200cu engine, but the valve cover says it's a 170. It may be the wrong valve cover. Does anyone have the timing specs for a 200?

 

[LaGrasta]

Forget about the sticker. Determine what you have by the cast stamp in the block. Run that on the vin decoder (on a number of web sites), then start from there.

 

[mjpchief]

Makae sure that your harmonic balancer has not slipped. If it has you can not set the timing right and this could also cause you running rough when hot problem.

 

[LEROY POLL]

HELLO MARK66

.....MARK THE TIMING IS SET WITH NO VACCUM HOOKED UP. YOU WILL THEN CHECK THE TIMING. IT SHOULD BE IN THE 6* AREA. IF IT IS LESS OR MORE THAN THAT, THEN RESET TO 6*. ROAD TEST IT TO MAKE SURE IT WILL RUN WELL. YOU CAN GO TO AS MUCH AS 11* ( PER FORD ) FOR A LITTLE MORE KICK IN THE PANTS.

.....MARK YOU SHOULD ALSO CHECK YOUR ADVANCE. YOU SHOULD HAVE AN ALL VACUUM SYSTEM. ANY LEAKS AT ALL, IN THIS SYSTEM, WILL CHANGE THE MOTORS PERFORMANCE.

..... NEXT CHECK THE ROTOR SHAFT AND ROTOR TO SEE IF THEY WIGGLES, OR WABBLE OR ARE OUT-OF-ROUND. THIS WILL GIVE CHANGING OPERATIONS.

.....YOU SHOULD ALSO SET THE CARB WHEN IT RUNS BAD. SOME TIMES IN THE WINTER THE CHOKE STAYS ON MOST OF THE TIME, BUT IN THE SUMMER IT WILL OPEN UP COMPLETELY AND WOULD NEED TO BE RAISED TO A HIGHER SETTING AT IDLE.

..... ALL OF THESE ARE MEANT TO GET YOU TO FOCUS ON JUST ONE THING AT A TIME. SO DO EACH ONE..... ONE AT A TIME. WHEN YOU GET THE MOTOR TO CHANGE AND RUN CORRECTLY YOU WILL HAVE FOUND WHERE THE PROBLEM WAS. YOU WILL ONLY NEED TO CHANGE OR REPAIR ONE PART. THIS IS A GOOD LEARNING PRACTICE AND MONEY SAVING HABIT TO USE!!!

.....GOOD LUCK ON THE WORK.

LIVE IN GRACE

LEROY POLL

 

[Anonymous]

Thanks Leroy and chief. I'll definitely go that route. Lagrasta, I've checked the manifold numbers, but every website I've looked at doesn't differentiate between the 170 and 200.

 

[CZLN6]

Howdy Mark66 and all:

If you have three frost plugs under the exhaust manifold you have a 170. If you have 5 you have a 200.

Remove the 1st spark plug and shinn a flash light in the hole. If yu can see a dish in the piston top you have a 200. No dish, you have a 170.

You didn't give your tranny type or your locale. Both could make a difference in setting initial advance and in tuning. In either case Leroy has laid out a sequential plan to pin down your problem. I might add that a good periodic carb and fuel system clean-up prevents the dirty carb syndrome. If you have a C4 auto trans, don't overlook a blown vacuum modulator.

Adios, David

 

[Anonymous]

Thanks. It is an automatic tranny and I will go through everything everyone has mentioned. I'm glad for this sight. Everyone has been very helpful.

 

[Williboy]

My Cutlass started doing this same thing the day the I go to sell it
Apparently the carb is leaking internally from casting holes inside the float bowl. A design flaw. ( I'm getting the carb back tommorrow so I'l know if that was the problem 100%)
Obviously, you don't have a 4v Quadrajet but you might wanna make sure its not leaking/flooding.
Also make sure your choke is working properly too.
GLEN

 

[Anonymous]

i had never heard that it could be the harmonic balancer...

mine needs replacing...maybe it is a combination of harmonic, and wobbly dizzy...check you dizzy...

 

[65coupei6]

I know alot of people will not agree with me but I never set timing on vintage cars with a timing light. Do it the old fashion way. A ear. You can check out my webpage for some info on how to do it.

 

[66Sprinter]

HEAR HEAR To marco..

I orginally set my timing by ear from Marco's directions..and had good luck before and after the pertronix...however I decided to go by the book and it was just awful...so I went back to ear and roadtest...I got a good setup now...as for the rough idle...I drove 148 miles today at about 80mph...through many small towns...at every light no idle problems. Stopped for a pizza with the wife and on restart it was THE ROUGH IDLE...after about a mile no more...just figure its cantankerous...no more problems the rest of the trip