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1970 Challenger 440 Fuel Issue

Started by jcbruce, February 06, 2020, 05:34:25 PM

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jcbruce

We don't have the new push rod yet but this is the best (of bad) pictures we got from the boroscope yesterday.  Just hard to get a good picture but you can see the top of the pushrod (cam side) is scared up.

RUNCHARGER

Ackh: If that is the cam lobe you were right, it is fried as well.
Sheldon

JS29

Check for filings in the oil and oil filter.   :alan2cents:


jcbruce

#33
Well, mixed results folks.  Everyone on this forum has helped a lot and it's appreciated.  Thanks to all of you once we got the pushrod from 440.com we knew what to do.  We checked the cam lobe, looked like new, no problem.  Just lubed the pushrod, put it in.  Put the distributor back on and, as someone else mentioned, had to play a bit to get our new fuel pump in with a pushrod that didn't look like a crayon.  Reconnected all the fuel lines and put a pressure gauge back in line with the carb.  Drained the oil and let it drain through a magnet.  No metal we could see.  New filter, oil and zinc additive.

Started her up, started easy.  Pressure was very strong (maybe a bit too much).  Anyway, fuel pressure issue solved!

Took her for a drive and just okay.  Runs pretty well but not much of a punch for a 440.  Got back, let it sit for 10 minutes and restarted.  Ran rough and died after a few minutes.  We then spent 2 or 3 hours playing with the Edelbrock carb.  Just couldn't seem to get it dialed in.  Overall about 12 hrs yesterday on it.

It's better, and the original problem is fixed but not a reliable ride yet.

Soooo....  next step.  Considering a much better carb (we know it would be better but would that be the end of it) or an EFI.

My heart wants a new carb as I'd like this to be as original (with a carb) as possible, my head says go EFI and long term it will be more drivable.

I know the thoughts will be mixed but the forum has been great so far, what do you think?  My car is NOT an investment, its for driving and having fun (if that helps).  I don't need a show piece, just driving.

Thanks to all.

PS... If you can suggest something other than what I've said let's hear it.

YellowThumper

Heat soak with the blended fuel available nowadays is a real issue. If you do not have a phenolic spacer now I suggest trying that first to see if you get improvements from it.
Only you can make the decision of carb v/s EFI. Think about what you want out of it along with it's intended usage. If driven regularly and you can dial in a carb. Then it can remain carb. If it will sit for extended durations in between drives. Then carb will become an issue and EFI should be a consideration.
Keep it a clean setup with throttle body and factory cleaner AND pump in tank. Most will never know it is not a carb.
But you will.
EFI will require updated alt. Updated wiring in bulkhead area along with shunting Amp guage.
Be prepared for more than initially expected.

I am adding EFI to mine just for the Efficiency. Get in turn key and go.
Life is to be viewed thru the windshield. Not rear view mirror.
You are the only one in charge of your destiny.

Mike.

usraptor

Just curious.  Have you checked your timing yet, especially since you R & R'd the distributor? I'd verify that is set correctly before you start shopping for a new carb or EFI just to make sure.  Not sure what cam or modifications to the engine you have, but you should be at about 36 degrees total advance.  Depending on engine mods you could have up to 18 degrees at idle.  The 10 degrees recommended in 1970 doesn't really seem to work as well with today's fuels, especially if you have an aftermarket cam.  You can always hook up a vacuum gauge to the carb while you turn the distributor and set it where you have the max vacuum at idle.  The vacuum canister on the distributor may have to be adjusted to obtain 36 degrees at higher RPM.  Do a search and there are a few threads on how to set the timing correctly.  Good luck.

ratroaster

How much fuel psi? Are you running a fuel pressure regulator? Eddy's don't like much over 6 psi.  You may have too much pressure now.  :alan2cents:


Chryco Psycho

this is the case for sure , he was peaking at 8 psi with the mech pump & I am sure it flooded out when it stalled

jcbruce

Again, thanks to all.

We put in a fuel regulator today (thought the same thing about too much fuel now - first not enough, now too much).  Anyway, backed it down to 4psi.  Took it for a spin and it had a lot more punch to it.  Just flooding out after we fixed the other issues I think.  I need to do a better job of matching things as a system versus parts and pieces.  But ...still doesn't run too well.  Died on  me on my drive, we worked with the idle and mixture a bit and hoping it's drivable at this point.

We will check the distributor timing, that's a good idea.  We did take it out and put it back in to see the top of the fuel pump push rod.  You mentioned 1970 timing but the motor isn't original and not sure when/ where it came from so we'd need to work with it.
I like your idea of maximum vacuum at idle.  Will check threads for some help with that.

Also plan on a phenolic spacer under the carb if we change it out (not thinking that's a major issue at this point).

I'm doing a wait and hold on a new carb versus EFI.  It feels like we are shooting in the dark to make the EFI change.  Not major surgery but would start to modify a car that was just put back in original (roughly) condition.  My buddy is claiming if we "just" got a new carb all would be good.  I did get a carb recommendation from Chryco of a ProForm 850 for it if I decide to go that way.  A new carb would be easier to try and tear up the car less but it could be wasted money/ time.

My plan is to drive it for a week or so (assuming I can) and just a feel for where it is after checking timing and a few other things.

Will keep you posted but keep the ideas coming.  I know it's hard to say from a message board what issues could be, and if you saw it you'd have a better idea.




ratroaster

Did you check your needles and seats? If you are running crappy ethanol the needle may have dried out and not be seating.