390 will not run right

[R.Smith]

Don't feel bad. I've been fartin with the timing, vaccum, dwell on my 390 since I got it a year ago. Last week I stomped it while I was going up an on ramp. it took off then for some reason strated lurching and gagging. I nursed it home and was all ready to beat it with a sledge hammer when I noticed the manual choke knob was all the way out. I guess the vaccum must have sucked the chock closed. Go figger. Runs good now. That'll learn me to spray teflon lube in the cable housing.

As for power...I pulled a UPS delivery truck that was stuck in mud in a neighbors yard up to the lugs out in one snatch. This was one of the large vans too, fully loaded. Don't ask me what compelled the driver to try and turn around in someones yard. I doubt he works there any more. The yard owner was not amused.

[70_F100]

It doesn't leak water so Idoubt if it is an intake gasket. Before we swapped cams it was weak too. This motor has never impressed me powerwise. I just want to get it back drivable so I can sell it

Just because it's not leaking water doesn't mean the intake gasket isn't blown. The intake ports are in no way related to the water passages.

Try putting a vacuum gauge on it.

[BobbyFord]

Have you put a timing light on it yet???

[Dragon]

Too bad you are so far away. My truck has almost every tappet ticking some more than others. Surely has bent pushrods from an over rev when I was in Carlsbad smoking the tires. The intake is from a 65 Galaxie and the heads from 61 Galaxie according to the codes. The rear main seal leaks still and the rear axle bearings are rough as hell. Oh and I can only get a bouncy 12 inches of vacuum at an idle with the timing at 10 BTDC and I have to run Premium.

With all that wrong with the truck IT HAULS ASS. Outruns most of the trucks in town without even trying. So If I was close to your truck I could get it going.

Always been weak, timing and timing chain first area to look. Does it miss evenly or just weak all the time? You can set your timing to 4 degrees and a FE will still haul. It will haul better at 10 or 12 but where it is set depends on fuel and altitude more than anything. I tried 12 with m High comp factory 10.25 to 1 motor and here it likes 10 better. Points at .017. After you set them turn the motor over and see if they change. If you remove the condensor the points will burn out faster just as if you use the wrong coil inductance (windings resistance).

Do you have middle of the gauge oil pressure? To thin or too low and the tappets if they are really worn like mine they will bleed down and not open valves far enough.

So you can rule out carb problems. Backfires won't rupture a PVC valve but they will damage a Vacuum Modulator(on automatics), Power Valve, and rarely a Vacuum Advance module. Plug the vacuum advance you don't need false signals while troubleshooting. Plug the PVC line and the PB line if if you have one. Get a vacuum gauge they aren't expensive and they can tell you areas to look at.

All Autolite 2100s are not alike. A Maverick 302 2V is way smaller than the one for a Truck 390. The truck 390 gets a 360 to 380 cfm carb, a 302 Maverick gets a 280 to 300 cfm carb depending on years made and emissions. A 360 gets a 330 cfm most years if memory serves me right.

[Jarred Hodges]

It has a 600 holley carb. I will put a timing light on it probaly next week. Its snowing outside so it will be a few days before I get out there. before I sell it I wish I could have the 390 at 100% for one day. A 390 with rebuilt heads, performer cam, headers, performer rpm intake and a 600 holley ought o run hard in theory.

[Dragon]

yes it should if the cam is advanced it will run like a smog motor. That was Ford's way of detuning engines for Smog. Those 3 to 1 gears don't help though if you have tall tires.