No more ideas out there? I'm wondering if I should put the new carb on and see what happens. But I still have a weak spark. I'm lost too.
Thanks.

 

No more ideas until the carb situation is figured out.

Although your less than 6 volts at the coil in "RUN" is sketchy, but I am sure it would come up once the alternator was charging.

You should have full 12 Volts in "start" Did you check that as well?

Josh

 

12v while cranking? Where? at the points? at the + side of coil?

I didn't check any voltages while cranking.

I did notice yellow sparking at the points while they were opening and closing during cranking. But not every time, just sometimes during the crank.




I have noticed your signature. 428 Cobra Jet Dual Quad. How do you keep tires on it? My buddy stuffed a 440 Six Pack in a 70's Dodge van. That was just stupid fast. It was down right dangerous... but fun!

 

Yes Full battery power at the + terminal while cranking.


Let's just say I have matured over the years. Not to mention I lost a hubcap last week and reinstalled my 31" tires and the week before that I put my 3.00 rear gears back in. (I had been running 3.50 gears and before that I had 3.70s, so it's been a nice break from the highway gears)

It feels like I neutered the poor engine.

Josh

 

It cant hurt to put on the new carb arrives did you look at what I told you about?

 

I can install the new carb, but once I do I can't take it back.

What was wrong with your truck? Low fuel pressure? I could check mine again but it sure throws out alot every pump. Nothing weak about that. Besides, right now I think I'm getting too much fuel.

I guess I'll see what the different carb does tomorrow.

Thanks

 

Ok, the new carb is on. It's not throwing up fuel anymore so that's good, but it still doesn't start, that's bad.

I am getting full 12volts to + side of coil while cranking. Spark is still weak (yellow) at coil and plug. Spark plug wire resistance is within specs.

Plugs closest to carb #3 & #4 wet with fuel (now, after cranking and pumping acclerator pedal) Plugs furthest away, #1 & #6 dry, but that makes sense to me. It's the only thing that does make sense about this whole "adventure".

Any thoughts?

 

Interesting... how charged is your battery? Maybe it just isn't spinning the engine fast enough to catch. If I were you I would throw the battery on a charger or jump it. No need to run and buy a new battery unless you want to load test it.

My motorcycle is that way and so is my riding lawnmower, the battery has to be at full charge to start.

You would say you have enough ingredients for the engine to fire (spark, fuel and I doubt you suddenly lost compression) Even a weak spark should at least TRY and fire the engine, and it sounds to me from your description it just turns over freeley?

Josh

 

Try checking the distributors mounting plate for your points and condenser if it moves enough to allow the points to slip off your shaft then one or the of the following things needs replaced. The three plastic nubs on the bottom of the plate let me tell you it is way easier to go to a junk yard and pull on off and replace the plate than the nubs. or the vacuum advance arm is warn and allowing movement in the plate.

As for my fuel problem it was a simple case of low pressure so the perfect time to go to an electric fuel pump over mechanical.

 

sorry it double posted for some reason

 

I had the battery tested last week. It was good but low charge. I have charged it since and most of the time I have jumpers hooked to my Ranger just so I don't run the battery down while cranking. It cranks real nice, just doesn't start. Spoke to an old timer that insisted that I try changing the condenser. So for a few bucks... why not. Well, I guess I have 2 good condensers now, because that didn't do it either.

As for the distributor plate, it doesnt wiggle or move except when I put a vacume pump on it while I was checking for vacume leaks, then the vacume advance moved it. Distributor shaft doesn't wiggle either. So I guess I can rule that out too.

Question: When I hook a spark plug wire and plug direct to the coil, I should be getting a nice blue spark, Right? It's the same yellow spark I get at the cap.

I'd pull my hair out but there's not much left.

 

Try replacing the condenser. Its purpose is to prevent arcing at the points when they open. If its bad the points can arc when they open and not allow the coil to fire properly.

 

Pull off the coil, and check the resistance of the primary and secondary windings. The primary winding is measured between the BATT (+) and TACH TEST (-) terminals. The secondary winding is measured between the BATT and large center terminals. Report your results. The primary winding should be about 1 ohm; the secondary winding should be in the 8-10 k-ohm range.

 

Mikeo0o0o0: I replaced the condenser today.

fmc400:
Coil resistance : Primary = 0 ohms using digital meter, 2ohms Analog
: Secondary = 9280 ohms digital... 10000ohms Analog

Just about the same readings I had from the coil I replaced a few days ago.

I was told by AutoZone that testing a coil, this way or even using their machine isn't accurate. Coil can test good but still be bad. Have you found this to be true?

 

Actually yea I worked at an Oreilly's for awhile and the same is true about all parts tested but things like coils and the like are tricky because even though they may be bad they will still pass enough current a lot of times to test perfectly fine