hi, we have a 1969 mustang fastback with a 351Windsor 2barrel in it. we have recently been in efforts to rebuild this car as it has been setting for the last 18 years under a tarp in our storage. yes, we know this is the worst thing we could have ever let happen to this car. but you know, when moneys tight the stang suffers.

anyways, in our efforts we have replaced most of the engines general requirments to run, all new gas tank, fuel lines, pump, carburator, fuel filter. starter, water pump, distributor cap, spark plug wires, coil, and in fact probably most of everything that could have needed to be replaced. in fact we think we have narrowed the cause of our problem down to one of two things.

we recently (as in the last 4 weeks) have had the engine rebuilt, and it runs, i will sit at idle great, and it will run like a race horse. only problem is that when gradually starting to accelurate, (not under a load) we hear this very specific sound, almost like a mid tone hiss and then the engine will bog down and if you dont let off the gas, or give push through it, it will usually kill the engine. by replaceing the vacume advance on the distributor and reconnecting the vacume lines back (to the right way by how we found a simple schematic for) the hiss can still be herd while not under a load accelurateing, but the engine dosent hesatate. but once under a load it will bog down on take off, and unless you quickly over accelurate to get through it, it will die.

my father is at wits end. he has such high hopes for this car being his dream car again. and we are kind of at a deadline crunch, we need the cars engine to operate flawlessly before the transmission guy will rebuild the transmission (so he can put it through the gears on the road without any problems), and he needs the car today or it will push us back three weeks to getting in the shop again.

we think its either the carburator, or the distributor.

our reasons for thinking this are because the carburator seems like the only complicated piece that we could still not have tuned properly (and it was also a re-built original). and the distributor because we have yet to replace it and our general logic tells us that in proper quantitys and times, the car needs three things. fuel air and spark, since we covred fuel, and we hope to think that air is okay. las thing we can point at is the distributor.

so. any help (information) would be greatly apprecieated. we may be completely wrong. and that uncertainty is why im posteing here. i understand the deadline probably wont be made but we need to get it fixed in the next three weeks so it can meet the next one.

 

i would say its the carb. since the cars been sitting for so long. go to autozone and pick up a kit. i just did my 2 barrel it was like $28 for the kit.

 

I would start with checking the timing. Then go for the idle mix screws...I start with them at about 1 1/2 turns, turn them in until it starts to run rough, then back them out a 1/4 turn. (turn them slowly, 1/8 turn at a time)

Also, cover the top of the carb with your hand (after adj's), if your motor continues to run, you still have a vacuum leak. maybe the carb base gasket.

 

thanks. we went ahead and installed the 4 barrel carb we had been saveing for when we found an intake for, we used a conversion bracket to get the job done. it runs great. we had tried tuneing the old 2 barrel and replaced everything we could on it and it still didnt want to co-operate. the car is going to need alot of work, but eventually it will be a treasure, we simply have to keep moveing from one problem to the next weakest link untill the car car no longer offers problems.