I have a 1985 F 150 4x4. I am doing an engine swap from a 300 i6 to a 302 with mild cam, bored .10 over, 4 bbl carb, and rebuilt. The problem that we are have is when it is put in to gear the truck dies and then when it is warm it will not re-fire. Don't know not what to do.

Need Advise

Thanks

 

Welcome to the site.

Have you checked spark and fuel? Knowing if you have either when it won't start will go a long way towards helping you diagnose the problem. Also, what ignition system are you running and is it compatible with the 302? Did you change the engine wiring as part of the changeover?

 

It could be many things.

If the cam is big enough it's going to hate the torque converter if you used the stock one. (Not to mention the i6 converter might be tighter than the stock 302 converter due to the higher low end torque..) I have to deal with the same crap. Could also be running lean, providing enough power to idle with no load but not enough to idle with the load of the converter..

The problem may not be that though, it could be whatever is preventing it from starting when warm. Possibly coil? Duraspark module? (If that's what you used)

 

First I will start with a parts list:
holly fuel pressure regulator
Cam and Lifters, Hydraulic Flat Tappet, Advertised Duration 262/272, Lift .448/.472, Ford, 5.0L H.O.
Summit Racing Street & Strip® Stage 1 Intake Manifolds
edelbrock 650 cfm electric choke
msd coil
PerTronix ignitor

We have had many problems along the way first we had to much fuel pressure so it would not run at all. We fixed that by putting on a holly fuel pressure regulator. We would also foul plugs I have gone through 4 different sets of plugs. We have fuel and spark. The ignition we have in it first was the 1985 v8 system and we could not get anything so we switched it to the the 1973 mustang system just two wire system. and got rid of the points and put a the updated PerTroniz ignitor We have it hooked right to the battery so if is always as power to make it run. That is when we had it running we have tried moving it and it just stalls out and can start it when its warm again. The torque converter have the same part numbers for both a i6 and 302 so that should not be the problem and we know that because when we put the engine in we use the 302 converter and still got the same problem. And we just swapped the 300 in ans till same result.

Need any more info let me know.

 

If you have the choke plate closed can you put it in gear without it dying? Or have another carb to try? Timing set correctly?

I looked up the details for that cam on summit and it based on what it says the stock converter shouldn't be any problem. "Smooth idle, great low-end horsepower/torque, towing, good fuel economy in stock engines. Good camshaft for turbocharging."

 

We have tried a different carb same result. The time is correct.

 

Could if be a vacuum problem?

 

It's a possibility. One thing overlooked could be the line going from the back of the intake to the transmission. Or maybe an intake leak. A vac guage would give you a clue if there is a leak.

 

Sounds to me like a timing issue

 

I have a question then it starts up fine when the motor is cold but when i try to start it warm I can get anything. What does that have to do with the timing?

 

The timing is zero'ed in.