Ford Forums banner

Ford 302 Hesitation and unsteady RPMs

11K views 12 replies 3 participants last post by  R.S.LOGAN 
#1 ·
Hello all,

I've been having some issues with my 302 in my 66' Fairlane, it seems to hesitate when accelerating, and has unsteady RPMs when cruising, usually around 1500 RPM, and has been a little hard to start. Was wondering if anyone has any ideas on what could be causing this.

I have some ideas, either the carb (edelbrock 650cfm) is screwing with me, like a blown accelerator pump or something.

Or i have a blown head gasket. There is some smoke (not a lot) coming out of my tailpipe, whitish, and only when motor is warmed up. Could be fuel, or coolant. Hard to say since i'm not loosing coolant.

Havent done a compression test yet, mainly because i have GT40P heads and taking the spark plugs out would be a pain.

Any thoughts would be awesome!
 
#3 ·
Not sure what's fitted on that engine but it could be something simple like a plug / wire / coil shorting or breaking down causing misfire .Normally if accl . pump knacked you get a massive flatspot . A block test will tell if head gasket causing the white smoke but could also be unburnt fuel possibly caused by plug / cylinder not firing all the time .
 
#4 ·
Thanks for info guys, appreciate. Sorry havent been on in a while, but just did a compression test on the motor, it ranged from 100-125psi, is that good?? could be worse i guess.

But the plugs did have a lot of carbon build up them. I think it may be time for a new carb. I bough the one i have now used from some guy i worked with, rebuilt it, then been running it for about 5 years, no problem until now. So a nice new Edelbrock may be the answer. What do you think?
 
#6 ·
I defiantly think its running way to rich, the choke is a manual one, and i usaully just keep it open and not use it, unless its really cold out.

I don't know all that much about carbs, but seems no matter how much i adjust the carb, it still runs rich. I've adjusted the two screws in the front, idle mixtures screws, and the floats and still no change. I dont know what size jets are in it.
 
#9 ·
R.S. is right, with out something to tell you what you mix is, you kinda playing blindfolded darts. I'm also in the NE and I know how cold Cape Cod can get. If you don't have to choke it until it's really cold, you're probably too rich. If the 302 is stock, the 650 on top is probably too big. A stock 302 as a daily driver should be about 450. A 650 can work, but set up can be tricky with a stock manifold an cam.
 
#10 ·
Thanks guys, really appreciate the help, i've been really sidetracked recently, but finally had a chance to get back to the ford this weekend.

So my cylnder pressure is good, and spark is good, so i swaped out my carb. I went back to a stock 2 bbl carb and intake setup. now i have new different problems. haha. It's hard to get the car to start, it will crank over, and eventually start, but it takes some time. Then it dies randomly at moments.

My guess is it's not getting enough fuel. Does any one know how to adjust these carbs? Could it be the float? Again, any information would be great!
 
#12 ·
Awesome, thanks!

So i rebuilt my edelbrck 600cfm, andput it back on, and went through everything again.
Torques all bolts down correctly
fuel lines
electical wiring
MSD box
spark plug wires

spark plug wires! Thought i checked them before....but not well enough. Since i have GT40p heads, i need special headers, and they run close to the spark plug wires. So i wrapped the wires in those heat protecting boot covers.... I took the covers off, and a couple of my wires were toasted! Guess when i overheated, it was too much for the boot covers to handle.

Replaced them and it runs great again. Something so simple... boy is my face red, haha. Thankseveryone for the input

But you know how these things go.... fix one problem, get another one.... Now my C-4 transmission wont shift into 3rd gear...... Does anyone know anything about theses trans??? I'll search the forums for info, but if anyone has any advise, again, it would help a ton.

Thanks again!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top