87 302 with carb and hard start issue

[2l8iwn]

A friend of my dad's did a 302 h.o. swap into his 83 mustang. He is running it with a carb setup and a pro comp dizzy, ign box, and coil setup. The carb is a holley 700. We initially went over to take a look as he couldnt get it to run. After fixing a timing issue we can get it to start and run. We set the timing to 8 btc with vacuum advance off. Once the car is started it seems to run very smooth and is very responsive. However, when starting the vehicle it has a very labored start. We even let the engine run for 20 min to get it nice and hot and it still has a very labored start. It kinda sounds like it has to much timing during cranking but i didnt notice any kickback. Any input on some things to try would be much appreciated.

brandon

[mustang8998]

I'd look at the battery (load test) and possibly the starter.

8* isn't very much timing, so that shouldn't even matter.

[85_SS_302_Coupe]

Check to see if the accelerator pumps are too tight. They might be dripping/dribbling gas after the car is shut off, causing a super rich condition while trying to start it. You should be able to look down in the carb and see if the butterflies are wet. If they are, back out the screws on the arms a little bit and see if that helps.

Also the carb is a tad large unless there's a lot of bolt ons or some kind of power adder.

[outlaw85]

Could also be a chassis ground problem with the lazy starter symptoms!

[orangedemon331]

As far as checking the starter, if it starts better cold than hot usally the starter is on its way out! If this isnt the case its a carb problem or try maybe setting the timing at 32 degrees full advance at around 3000 rpms and see what that does! Hope this helps!

[mustang8998]

Could also be a chassis ground problem with the lazy starter symptoms!

Oh, yeah, this, LOL!

[2l8iwn]

First off thanks for all the replies. We swapped out the battery with the one in my car and it still hard starts. I checked the battey ground and the ground strap and both are fine. I think you might be on to something with the accellerator pumps on the carb. It seems as if you feather the pedal a little it seems to get a little better and will actually get the motor started. Now i am no carb guru i leave that up to my dad. I do know he turn a little screw on both sides of the carb and told me he was trying to lean the mixture as much as possible since the carb is a little much for that stock setup. Also the hard starts are the same whether it is hot or cold. no difference. Ill talk with pops and see about the dribbling effect with this carb. ill post back as soon as i can. many thanks

brandon

[85_SS_302_Coupe]

Those little screws are really not to be played around with unless you really know what you're doing. I'd suggest screwing them both back all the way in (don't CRANK them down, just screw them in until you feel them stop) and then back each one out 1 1/2 to 1 3/4 turns and make sure you do both sides as close to the same as you can, and then leave them be.

Are you pumping the gas when it's hard to start? Try this...after you've ran it and it's warmed up and it's giving you hard start issues...don't pump the gas, push it to the floor and hold it there and crank it over and see if it starts.

[Metcalf Racing]

Un hook the vacuum advance and set total timing at 32@3000 like orangedemon331 said. This will fix it

[Metcalf Racing]

Oh and leave the advance un hooked

[rapidfire89]

another idea, just my .02 cents, deffinitely look into a smaller carb. on a relatively stock 302, anything over a 650 is too big imho, problem he may be running into is that with such a big carb with bigger venturi's its naturally going to flow more air naturally needing, not wanting more fuel, if its 2 not 4 corner idle, try opening up the secondary blades just till you see the rear transition slots just a hair to get a little more air in it to lean the mixture out, or start jetting down.

biggest problem he is going to have is no ability to adjust the idle/high speed air bleeds, since im assuming this is a typical 4776 main body and the bleeds are pressed in.

if he decided to go proform mainbody though, 65 primary/72 secondary jetting, with a 28 squirter with .034" bleeds all the way across the secondary side (2corner idle) and .076" idle air bleeds combined with .036" high speed bleeds on the primary side, give a relatively stock 302 the characteristics of a 650 holley street hp.

he doesnt want the primary trans. slots open too far, itll start pulling fuel from the main circuit.