Engine trouble..... Electrical???

Hey guys I'm a little stumped so maybe some insight from others will help. I have a 74 Maverick Grabber 302. I just put a new motor in it and the plug in for the distributor crumbled. I didn't have time to work on it so I took it to my local very trusted mechanic. I told him get it running so I can cruise in it with no worries.
Ok, so he checked why the wipers aren't working and said there was an under dash issue (he doesn't do large scale electric work on cars). He replace the Dist. and voltage regulator which was bad. When I put the motor in I installed a new starter and spark box. So I pick it up and get it about a mile down the road (300 yards from home) and the carb backfires twice and I start losing power, a few seconds later it stalled. I coasted in my driveway. Now when you turn the car over it acts like it has a dead battery and gas pops up out of the carb. very slow hard turnovers. I unplug the coil and the car turns over normal just as it should, no backfire out of carb no gas popping up. I installed a spare coil and it went back to hard turnovers again...... Any thoughts? Bad new distributor out of the box? short somewhere? Any help would be great.

Simon from Ohio...

 

OK so I tried an old school method to see if it is shorted. I jumped the two large posts on the solenoid with the key in the on position. it turned over a little better but bogged down and repeated as such and backfired. Can I rule out the ICM?

 

Backfire out the carb generally is a timing issue, I'll guess the dist isn't tight and moved which skewed the timing... If dist turns freely timing is likely off, if it's tight there is likely other issues... As stated already may be ign module, often best troubleshooting is just sub another...

BTW if you had a DEAD battery it wouldn't crank at all... Big difference in dead and weak...

 

Thanks Krazy Comet, I meant weak battery, but in my opinion if a weak battery wont crank it, it's dead meat
First thing I checked was the Rotor button (I had one fly apart once) and distributor and it was tight, no movement. My ICM has a lifetime warranty so tomorrow I'm going to replace it just as a part swap trial fix. After that, back to the mechanic I guess. If it is shorted does anyone make a good dash and or engine harness for Mavericks?

 

I noticed something new as well that I didn't before. with the key on the ALT light in on in the dash. I don't ever remember it working before.

 

Well this motor is rebuilt and It doesn't have plastic cam gear and the chain is a year old.
As for the ALT light coming on, I know it's normal, but it never worked before, possibly because the voltage regulator was bad and I replaced it?

 

The regulator was bad and the battery wouldn't charge, the batter acts like its weak and dying when the coil is hooked up, you unplug the coil and the new battery will turn over fast. plug it in and the motor bogs down. I haven't seen any bare wire, ICM?

 

Yes the alt light is operated by regulator...

Labored cranking with coil connected indicates a out of time condition...

 

Ok I have been working on my fords for years but haven't had this problem before, could you elaborate on that? The Distributor is tight, new, and started like fuel injection and not so much as a hick up until a mile or two down the road. it's weird that being out of time would cause it to labor but with no coil crank fine.

 

with the coil unpluged there is no plug fire to cause an out of time cyl. to try pushing the piston back down BTDC.

 

Overly advanced timing will cause hard cranking as the cylinders are firing before TDC... Possibly a bad module can do same, as there is a retard function built in module that's supposed to reduce timing while cranking... Back firing out of carb is usually due to retarded timing, but won't cause hard cranking... Sooo you have conflicting symptoms...

Since it was just repaired, probably be a good idea have your mechanic look at it again...

 

I'm going to change out the ICM tomorrow and take the #1 plug out and TDC it and see where the rotor lies. After that I'll be looking a an engine harness and dash harness. I figure craig will have them but is there anyone making new harnesses? I did my 68 mustang years ago with a Painless wiring harness..... not so painless...

 

I'm going to see about the timing first thing in the morning and I have an ICM so I'll look at swapping that too, while I'm there. Thanks for all the help guys, I never had a car act like it was out of time while running so good before. It really stumped me, that and working on this car every day for four weeks to get it running to drive it before winter has burnt me out (hence why I took it someplace for a new distributor after doing a whole motor).

 

I really love my grabber, I just want to drive it. 102K orig. miles on car (motor new)

 

motor..."all new"... may have a bad new part...