Engine WEIRD FAIL

[Nacho-RT74]

on a buddy's mine 73 with 400. we can't get and keep running the engine and when we get, just runs afew turns EXTREMELLY ROUGH and stops... fully throtle

-We have spark, even he is using a Femsa ( Ford ) ignition module.
-We have gas.
-Is on time, even we have moved the distribuitor to try to start it and keeping running.
-Gas is flowing like a river once engine is started throught the venturies, but Carb is new. Checked floaters level and is good.
-LOTS of explossions throught exhaust, logical, is some out of time, but EVEN ON TIME. We had someone explosion like a firework or gun on exhaust pipe... damn that was scared... BOOOOOOM.
-Damper mark is good and meeting with TDC 1 piston.
-remove air filter and we could smell and SEE gas vapors throught the valve cover filter. Removed valve cover and we could smell lots of gas

your thoughts

I know this is really weird.

[TylerCharger69]

The dampner hasn't spun on itself has it?...meaning the outer ring has spun freely from the inner causing an improper timing reading.   That Ford ignition box isn't helping matters either.  I believe the voltage on those boxes is different than a Mopar product.

[jg68]

on a buddy's mine 73 with 400. we can't get and keep running the engine and when we get, just runs afew turns EXTREMELLY ROUGH and stops... fully throtle

-We have spark, even he is using a Femsa ( Ford ) ignition module.
-We have gas.
-Is on time, even we have moved the distribuitor to try to start it and keeping running.
-Gas is flowing like a river once engine is started throught the venturies, but Carb is new. Checked floaters level and is good.
-LOTS of explossions throught exhaust, logical, is some out of time, but EVEN ON TIME. We had someone explosion like a firework or gun on exhaust pipe... damn that was scared... BOOOOOOM.
-Damper mark is good and meeting with TDC 1 piston.
-remove air filter and we could smell and SEE gas vapors throught the valve cover filter. Removed valve cover and we could smell lots of gas

your thoughts

I know this is really weird.

You mentioned that the carb is flowing like a river, this is NOT good, sounds like its dumping gas & floading out BAD, pull the dip stick & see if you smell gas in the oil, what kind of carb is it?

[Runner]

check your bulk head conector, i had an issue with mine and it made a round muffller oval,  also the carb flowing fuel like a river isnt a good thing at all

[moparguy01]

im betting a float is stuck in that carb. Also the voltage is different between a ford and a mopar box at least up here, maybe the ones you have there are different. Also if you can swap a different set of plug wires on. I just had this problem the other week where they tested out just fine but the insulation wasnt thick enough and it let the spark arch from the wire to the block.

[Steve P.]

Nacho, tell us more about the problem.

Is this a new build?

Old runner that had been running well and just started this?

Any recent work done on it??

Miles??

You know the drill....

[Nacho-RT74]

One year from rebuilt, but with all cheaters on mechanical job down here we don't know certainly what was replaced and what wasn't... daily driver. Miles/kilometers, dunno, speedo wire is damaged.

He oftenly got some gas problem with mechanical pump that wasn't sending gas to carb, specially with engine hot, so he installed recently ( a week ago or so ) an electric one. Anyway we were trying to start the car with electric gas pump turned off and turning on just when we saw glass filter emptied, with just gas on carb ( full ), to be sure is not too much gas pressure what makes flow excesive gas on venturies

Carb is a NOS, TQ, to International truck 800 cfms, but still new and works. For a while we were trying to locate the fail, the engine was getting worst untill start and then just stop, so I can't say you actually if gas is flowing throught ventury like it was.

We installed my carb and "Gas fail" on carb didn't change with my carb. Last time I used my car 3 months ago was a perfect running one. We haven't got chance to see the gas flowing throught venturies on my carb because fail got worst before that.

We replaced also dist for mine one, recently rebuilt by me. True we got better blue spark with my dist, maybe becuse pick up coil gap was better graduated but still didn't change.

Spark plugs are new.

Spark plug wires... to check that we installed one set not new but they are my inmediatly replacement I have storaged in case of emergency and last time I used they were in PERFECT conditions except for two of them were slightly burned on exterior cover, but already isolated with tape and shrinking tube. I'm sure no missed sparks or "leaks" around because they were on my car after repaired for a while I got the new ones with perfect results. No changes with that.

We fit a wood plug on spark plug place and got compresion/explosion on TDC at Damper

about different module... I know that but "EXPERTS" down here have told him they are better... ASSHOLES... anyway with that module was working fine enough.

STILL THINKING ON WHY TE HELL WE CAN SMELL GAS AND EVEN SEE GAS VAPORS throught the valve cover filter and also whne valve cover was removed

[Chryco Psycho]

sounds like it is flooding to me , too much fuel pressure or a problem with the needle & seat in the carb 

[Nacho-RT74]

we thought that so we ended disconecting the electric fuel pump, to making work just with gas on bowls... nothing changed