This is my first post and hoping I found the right place to come, I am fairly new to the Mustang world, used to own a 64.5 Mustang for a couple of months til times got hard and had to part ways but have just purchased a 69' Mustang coupe hardtop to work on and am back in the game. She has a few things here and there but a # matching 351-W so not doing to bad. My questions are however just getting used to the new car and I found that I have to ease into the throttle because too much gas and the carb backfires. I first thought a timing issue but played with the timing and same thing happens. I then assumed the choke and have since been playing with the choke which seems to be the issue however I can't get it adjusted right and can't figure out what I need to do exactly. Could it be something else that is the problem? The motor has a holley performance carb with an electric choke. Also my other question is that the fuel gauge doesn't read correctly, I filled the tank and the gauge reads half and after maybe 30 miles of driving goes down to almost empty, what could be the issue here? And I was looking to replace the hood for an aftermarket hood (but still hold onto the stock one of course) however can't seem to find one for a 69' that isn't fiberglass, any ideas where to shop around? Finally I know that the 69' Mustang Grande's came just like the coupes but with a vinyl top and I believe the windows were slightly different but how do I know if mine was at one time a Grande or if it is actually a factory coupe? Any help is much appreciated, sorry for the novel just wanting to start off on the right foot.

 

About the Grande part, the body style code on the door will tell you.

65E is Grande.

 

I was having the same problems with bogging off the line and backfiring on my '67 289 and I backed out the air/fuel adjustment screws using a vacuum gauge to go by, and my problem is no longer there. With my air cleaner off, mine would shoot flames when I was starting it before I got it adjusted correctly. As far as your hood goes, I haven't seen any aftermarket ones that aren't fiberglass. I have been looking for a Shelby style hood for a while and no luck except the fiberglass ones. Maybe someone else can help out on here. Good luck!!

 

How do I go about adjusting that? I'm new to the motor itself and adjusting it so any guidance is appreciated. Thanks again kyle.

 

The code on the driver door showed 65A which I'm going to assume makes it a factory coupe correct?

 

Also check your fuel pressure too.

 

My guess is maybe the fuel to air ratio is my problem but I'm not sure how to check this myself. Any kind of adjustments I can do myself to get this conflict resolve? She's got some power behind her just needs the extra push (if I ease in to the gas and then lay into the pedal it will chirp 2nd gear everytime).

 

For the fuel gauge reading, I suspect the float is partially full of fuel and being weighted down. It'll probably need replacing.

However, there is an IVR or instrument voltage regulator that could also be the culprit, are your other gauges reading correctly?

 

The fuel guage issue could be that someone put a new chineese seender in it. Drive it until it gets to empty, then drain the tank. I'm guessing you'll still have about 13 gal's in it. If so, pull the float and bend it down some...(it's more a trial and error thing than anything)


The way I do the idle mix is to turn them all the way in (with the motor off)..note how many turns they were set at. Turn them out (CC) 2 turns. Start the motor and let it "settle". Motor should be up to temp also. With motor idling, start turming them in, 1/4 turn at a time. Turn them both 1/4 turn then wait a few seconds for the motor to catch up to you. There will come a time wheen the motor will start to stumble after you turn them....stop at this point and back them out 1/4 turn....that is the point theey will want to be.

Can't help on the hood. Why would you want to change it, anyways? Happy to see another 69 coupe though. Not enough of them around here.


Also for th backfire, chck to see if your vacuum advance is working.

 

You need to tune the carb (idle screws, jets, and throttle position), check your timing, and check for vacuum leaks. Backfires and bogs are not normal, so something is wrong with the tune...probably running too lean.