Hard to start, then dies

[Straight_6_tuner]

Hi All,

I have a 67 mustang with a 200ci straight 6 and its hard to start. I have checked the fuel lines all the way up to the carb and its getting fuel up there. Lately I even replaced/upgraded all the ignition system ie the spark plugs, wires, coil, upgraded the points to electronic ignitor setup, new distributor cap, rotor and it still does not run smoothly. So far I can start it but then just abruptly dies after about 10-15 seconds of idling. Any ideas? Any help would be much appreciated.

 

[rbohm]

8) first start by checking the fuel flow through the lines, not just "its getting fuel", but rather how much fuel is it getting. if it is coming up is drips and drabs, you are not getting enough fuel. you should get a fairly steady stream of fuel coming out of the fuel pump that fills an 8oz can half way in a few second of cranking the engine. if the latter is the case, then you need to attack the carb, assuming you are getting a good spark to begin with. and just because you thew a bumch of parts at the ignition system doesnt mean it is right.

you also want to check for vacuum leaks, especially at the carb adapter to intake point. that gasket is often overlooked when replacing gaskets and they can harden up a leak due to heat soak over time.

 

[Straight_6_tuner]

Thanks for the advice rbohm, I hope check for leak and fuel pressue/amount and hope this will fix the issue. If not, I recently just picked up a carb rebuild kit for my holley 1940 just in case. Never rebuilt one of these before but it can't be too hard. By the way, do you happen to know how to check and adjust the timing on the straight 6? I can't seem to find the information on how to do it properly.

 

[rbohm]

not fuel pressure, fuel flow, there is a difference. pressure only indicates how hard the fuel is being pushed, flow indicates how much.

 

[ludwig]

By the way, do you happen to know how to check and adjust the timing on the straight 6?

First and foremost, you need to find TDC (top dead center). I'm sure you already know that but there are children watching.

Remove the spark plugs to help you turn the crank more easily. Use a socket ratchet wrench on the flywheel/dampener bolt to turn the crankshaft. Remove all the things in the way and put your socket wrench in place. Turn clockwise.

There are three or four ways to find TDC. I have done two of them

1) Finger in #1 (frontmost) cylinder. Stick your index finger in the first spark plug hole and turn the crank until you find pressure building on your finger. When the pressure stops building, that is +/- TDC. The if you can see the piston through the hole but there is no pressure when you turn it, you have the exhaust stroke. This is not as precise as the next two but you CAN tell if you are on the right stroke.

2) Long rod method. Same spark hole. stik a welding rod, dowel rod or long screwdriver in the hole. Turn the crank until it stops rising. That is the top of the stroke. You don't know if it is exhaust or compression.

3) Bolt or too-long spark plug. Screw one or the other of the objects in the hole. Turn the crank until it stops and you can't turn any more. Make a mark on the timing ring. Turn it back the other way until it stops. Make a mark on the timing ring. Measure the midpoint between the two marks. That is TDC. But you don't know if it is exhaust or compression.

4) String in the cylinder method. Stuff a bunch of string in the spark plug hole, Turn the crank until something stops or something. Then start to pull the string out at some point. I really don't know how this works but some guys swear by it. Whatever.

When you have found the REAL AND TRUE top dead center, mark it on your timing ring. They are notorious for slipping after 40+ years on a dry rubber bushing. In fact, you might want to make the mark on the bushing too with a white paint pen. Now you can start to set your real timing from the real TDC.

Of course there is the part about re-stabbing the distributor if you took it out. You can do this with the distributor in but you can figure that out with the position of the rotor and the #1 plug lead.

Adjust the timing by loosening the clamp at the base of the distributor shaft. Turning distributor counter clockwise advances, clockwise retards. Use a timing light on your new mark and check it against the degree scale to the side. Specs on line or use the 'search' function. Stock adjustment will be with the vac canister at about the 2 o'clock position when facing the block from the driver's side.

 

[mluck]

would not tdc be if you took the cap off and the rotor was pointing at number one cyl ...????..just a question....

 

[rbohm]

would not tdc be if you took the cap off and the rotor was pointing at number one cyl ...????..just a question....

no. tdc needs to be the piston at the very top of its stroke. if the ignition timing is close, then you can get close by turning the engine until the rotor is pointing at number one, but given that ignition timing is usually set at some point btdc, you are only close.

 

[Straight_6_tuner]

My timing was in good shape. I did find out that there was a small leak in one of the fuel line. I am trying to order new ones but I need the date of manufacture of my mustang to find the right ones. Do you happen to know how to find this information using the vin? I know my mustang was built in 1967 but not the month or day. The vin is7r01t162622 Please let me know.

Thanks

 

[rbohm]

My timing was in good shape. I did find out that there was a small leak in one of the fuel line. I am trying to order new ones but I need the date of manufacture of my mustang to find the right ones. Do you happen to know how to find this information using the vin? I know my mustang was built in 1967 but not the month or day. The vin is7r01t162622 Please let me know.

Thanks

why not just make your own? you can buy steel tubing from the local parts store in a variety of lengths, and get a tubing cutter, and then just bend up the line as you need to run, and cut to length. then a short section of rubber fuel hose to connect the line to the carb, and you can save a some money as pre bent lines get expensive and dont always fit like the should. the only other tool you need is a tubing bender of you dont feel confident bending steel tubing without kinking it.

 

[bubba22349]

You can find your cars build date code on you door ID tag info (if its still got the original door tag) if it has the same vin code then it's should be original. Good luck

 

[Straight_6_tuner]

what happens if I do not have the door tag? Is there a book that shows when they were built?

 

[bubba22349]

Yes there is a way to know, since you have a 1967 you can get a build report (standard to elite) from Marti Auto ( https://www.martiauto.com/reports2.cfm ) and you can also get a reproduction door tag prices vary depending on how much info you want. From reading your code can see its a 67 2 door hardtop (coupe) had the 200 six was built in San Jose, Ca. and is unit number 162622 this would likely make it a mid to late production car, but to know much more would need the monthly production numbers for that plant. For example at the Pico Rivera plant where I worked we would build 60 per hour and could also work 10 hour days Mon. To Fri. And 8 on Sat so roughly 3480 cars built per week. 1967 production could have started in late July 1966 first car off the San Jose line would be unit number 100001. Yours is the 62,622'nd car off that line and so is built later in 1967. Good luck

 

[rbohm]

8) since the unit number is 162xxx it would mean a build date in early to mid july, thats where my 66 coupe landed with a similar run number.