donkeydiver

Hi,
I have a '67 GTX with a built '76 440 in it that I purchased last summer. Ran fine for very limited use 2nd half of the summer, parked it in my shop over the winter. Tried to start it 2 months into winter, nothing. Messed with all kinds of things at first and sometimes it would start fine, other times, nothing. I have swapped in 2 new pumps (1970 Road Runner) and the 2nd one worked great . . .for about 20 minutes over 2 days. Now nothing . . .even with the pump isolated with hoses in and out of a container of gas - I know it's not a hose or connection issue. The steel fuel rod measures exactly 3.22 as it should. The cam lobe seems to be pushing the rod about 1/2 and inch of travel when I reach up into the pump opening and feel the rod travel. Hard to believe it's the cam lobe since the thing stopped pumping all at once (over the winter), but then will still pump big time when it does run. Once it starts, it's fine and feeds even through big time acceleration. So the pump that came with the motor and was working fine began working intermittently all of a sudden. The 2nd one, nothing, the 3rd one, fine then nothing. I'm stumped. Ideas? Thanks.

Archer

donkey -

Ah, before you go too nuts, a quick check of the fuel filter might prove helpful - especially if it's one of the Mr. Gasket glass types. Don't ask me me how I know ...
The "test" btw- is to replace it with a more generic can type filter.

OK, personal experience aside, if you're sure it's a fuel problem (no fuel smell, dry carb), it can be anywhere from the tank to the carb, and you'll have to check/replace every piece. Again, been there, done that.

Archer

Iowan

Don't believe the Gage, is there fuel in the tank? Been there done that.

donkeydiver

Hey guys, thanks for taking the time to consider the problem. Been down all the suggested avenues, not so much. The kicker to the whole ordeal is that I've gone as far as isolating the pump itself by putting both the intake port and outflow port into a container of gas, cranking the engine - no flow. Seems like it HAS to be the pump, but now I'm doubting that after 3 in a row. (odd that the one that came with the motor went from working fine to working only sometimes . . .and the 2nd one worked fine for 2 days then stopped), the fuel pump push rod (3.22" exactly) or the cam lobe (can feel it pushing .30 to .50 I'd guess). Freaked it's the cam lobe, but that just doesn't seem logical given the movement and the on again off again fuel flow. I've got a '74-'78 pump on the way instead of the 2 '70s I've tried, but they look the same and the parts guys said they're basically the same. Hmmmmmm . . . .

Archer

donkey -

While cam lobe wear is possible, think about it, if the cam metal were that defective, the valve lobes would have gone first, since they are under higher pressure.

If you really think that's it, pull the pump and insert a longer rod into the pump push rod opening and slowly crank the engine or better, have some one rotate it with a breaker bar. A bore scope might help, but usually isn't necessary.

I guess you could manually quickly compress/release the pump lever to test the pump independently of the engine.

Having been through a very similar problem last year, all I can say, is that it will be the last thing (and the stupidest thing) you check.

Archer

donkeydiver

Hey Archer - Yeah, that's my thought process too, the fuel rod lobe would be the last to go in theory. Then I thought maybe it's a billet cam that whoever built the motor neglected to put the brass tipped fuel rod into and the steel ate the lobe. But . . . .why do I still have .50 of rod travel and raped ape engine performance and easy starts when the damn thing does pump. This is just a crazy stupid issue. Seems like it has to be pump, rod or cam none of which seem plausible. WTH?

Archer

donkey -

I'm still betting on something down stream of the pump, that would be the filter or carb itself. The only thing that doesn't match up is that the pump(s) didn't pump when you had external ins and outs.

The easy start up and power are normal, since the carb bowls are full, but once they drain, your dead in the water.

Archer

Iowan

Why are you using a mecnenal pump?

donkeydiver

I isolated the pump with the in and out hoses in a bucket of gas, then cranked the engine, specifically to rule out the filter and hose possibilities. The pump should pull that fluid lickity split with no lines or filters interfering. Nothing.

I'm using a mechanical pump because they've never been an issue before on any of my Mopars. They're quiet, cheap, original and have fed the hell out of my long list of gas sucking 440s in the past. I thought about skirting the problem and hooking up an electrical, but I'd much rather know what the heck is going on and THEN make that decision rather than be forced into it because I couldn't figure out the problem.

Archer

donk -

That pretty much leave the pumps at fault. Odd having multiple pumps fail. Assume you're using a good Holley or Edlebrock pump?

The only other test I mentioned would be to manually operate the pump by hand OFF the engine. For some weird reason the push rod may not be activating the pump arm, when installed.

You are correct using a mechanical pump. A normally aspirated engine does not need an electrical fuel pump, it one more thing to worry about. In most cases, the mechanical pumps are as reliable as you're going to get.

Archer

donkeydiver

Very much appreciate your continued attempt to help me solve this riddle, thank you! I'm with you on the mechanical pumps.

I've actually just put in 2 generic pumps that I got from the parts store that were labeled for a '70 Roadrunner. Like I said, they were supposedly the same thing on a '76. I've got an Airtex pump on the way that was listed for a '74 to 78 440, so we'll see if that makes a difference. Seems like there must be a difference, but who knows. I probably should've gone name brand on this 3rd pump, but it's never been an issue before. It should arrive tomorrow. I'll definitely give you an update when it goes in. Thanks again.

Iowan

I would pull the sender in the tank and inspect it for cracks allowing it to pull air. At this point I would be tempted to hook up a electric pump at the mechanical location just to see if it would pull fuel.

Archer

donk -

My pleasure - especially since I went through the same thing last year ...

It might not be the pump. The push rod may be the wrong size FOR THAT application. I would still manually test the pump off the engine.

Iowan -

Even though that solve the pump problem, it wouldn't diagnose the problem - unless of course the problem persisted. It was the next option I was considering for my car, until the real culprit was found.

Archer

donkeydiver

Now you're entering the Twilight Zone aspect of the problem. Not the pushrod, it ran/runs fine . . when it runs. Hard to test the pump off the rig since the spring is a bear to move at all. Seems like if it were the cam lobe, it would either work or it wouldn't yeah?

When it first quit over the winter, I'd do this and that (swap inline filters, swapped out old Moroso regulator for a new Holley, swapped out new filters at the carb inlets . . .seemed like each time I did "something", it would run again for a bit. Odd coincidence it seems though since now with the pump(s) pulling and pushing into a bucket there's nothing . . .even the one now that got the X running for 20 minutes when i first put it in.

P.S. My biz partner is an archery nut who was nationally ranked in traditional competition a few years back.

Archer

donkey -

Why are you using a regulator with a mechanical pump and a carburetor?
That motor should be happy with anything between 3 and 7# of pressure. The regualtor is just one more thing to go south.

Everything has a threshold. If the lobe moves the push rod, "X" mms, it should work, it moves it "X - y" mm is might not or be iffy, but yeah, that's pretty weird.

BTW - just for grins, did you ever check/replace anything in the carb, like the needle and seat? A bad needle and seat will dry out the carb pretty quickly.

From what you're describing, there's either something we're both missing, or you got a really bad run on pumps.

www.shootingthestickbow.com he's probably seen that.

Archer

donkeydiver

There was a fuel pressure regulator/gauge on the car when I got it. When everything went henshit, not knowing if the existing pump was some mega PSI deal (agree about not needing one with a mechanical), I took apart the Moroso and it was a mess, so I replaced it for $31 with a Holley as the first step. It seemed to work since the car immediately ran again . . . briefly before the problem reared its ugly head again. If the new pump works, I'll definitely pull the regulator.

Yup, a crazy run of bad pumps or a really odd manifestation (I guess. . .not sure how that would show up) of lobe wear.

Did you write that book? Very cool if so! Sure he's aware since it seems "traditional". I'm more of a rifles out to 1,000 yds guy myself . . .probably 'cause I couldn't hit a barn with an arrow! ; )

Archer

donkey -

I can almost guarantee ya, it's gonna turn up being something stupid. Always is. While possible, not buying the lobe wear thing, rod wear I've seen. edit: wait minute... the problem showed up AFTER you replaced the regulator? Swap out the regulator with a clean piece of pipe/hose and see what happen. Fuel pressure at the carb should be 3# MIN and preferably 5 - 7#. Also check is the fuel pressure drops as you rev the engine.

Yeah, the book is my fault. After 35 years, I'm leaning more towards Olympic than traditional, since when I started "trad" wasn't a word. Been doing Olympic for about 12 years now.

300Win Mag @ 2,950 fps @1,000 yds + 308 across the course = master rating. That was a few years ago, though. Most of the decent rifle ranges closed up around here and right now archery (ranges) ain't lookin' too good either.

Funny, we have plenty of room for a race track/drag strip east of me too, but local gov't won't let that happen either. How's the weather in Montana?

Archer

donkeydiver

LOL . . .yeah, hoping for stupid instead of catastrophic. Betting on the pumps myself, but we'll see. My Super Bee never gave me anything as mysterious as this and I ran that car for years. Oh well, still getting to know this one.

The problem actually began after I parked the car for the winter (when it rumbled into the shop running fine), and then wouldn't start when I went out to keep its blood flowing mid winter. Messed with the regulator as the first of many attempts at a fix, many of which seemed to work temporarily. I finally just isolated the pump into a bucket and narrowed all the potentials down to either the pump, the rod or the cam. None of those seem totally plausible though based on the random and intermittent nature.

Never been a competitor (shooting that is - 9 years on the rodeo circuit/2 pro and about 6 in the MMA game), but I've been shooting the same .308 since I was 7 and have about 10 other rifles dialed in big time. Clocked a standing antelope at 1050 yds about 6 years ago/ 30-06 165gr bt in 20 mph wind - one shot. 500 yard speedgoat hauling *** with a mod. 99 Savage .308 150 gr JSP - 2 shots. Just like building loads, seeing what they'll do and hitting my targets! Sounds like we have that in common too!

Been manic weather here with a few days in the 80s already. Been nice for jumping off the cliffs and mountains way earlier this year, but I'm betting on an active fire season based on what I've been seeing. Cool and rainy today which is the way it should be.

Archer

donk -

I'm betting the engine was just cranky after sitting a while. Messing with the regulator seems to be when things went from bad to worse. Loose the regulator and replace the pump AND rod with a known unit from Holley or Edelbrock. Also make sure you can blow air through the pipe/hoses easily from the pump in BOTH directions (pump to sending unit and other end of the pump to the carb inlet).

Just for giggles, clean or replace the needle and seat.

That covers it from wend to end.

Archer

donkeydiver

Archer - I'll definitely let you know. In the mean time, I investigated "Olympic archery" a online just to familiarize myself a bit. GEEEEEZE . . . you're a glutton for punishment! lol That's crazy stuff that seems like it could drive you much more crazy in short order! Precision stuff. Between the stickbows, long range rifle shooting and the Olympic realm, it must bug the hell out of you when you see a beer out of place in your refrigerator!! Thanks again for your input.

Archer

donk -

Re Olympic Archery: It's not as complicated as it seems. Most of the stuff you see on-line (and a lot of people try to use) just isn't necessary. The stuff that is necessary, isn't used from the get-go, but added gradually over years. The same theory with race cars, if it doesn't make the car go faster (or safer), you don't need or want it.

Heck you think that's bad, you'd hate to see my engine bay ... and if there's a beer out of place in my fridge, it means I'm not drinking enough...

Archer

peter123wallace

Yap. Efficiency over aesthetics anytime.

donkeydiver

Well, here it is, the puzzle is solved. Answer? A very confusion inducing combination of 2 issues at once - 2 bad pumps right out of the box and enough sludge in the tank to nearly shut down flow. The short version is that I got the 3rd new pump, installed it and hooked it up to the car's tank and a hose into a bucket from the outflow. Cranked the car over with the remote starter and watched what happened - nothing - for the 3rd time in a row. Just had to laugh and walk away which I did. Came back an hour later absolutely clueless since this had been the same routine with the original pump, and the 2 prior new pumps. I had taken great care to remeasure pushrod length and travel once again before installing the final pump and all was perfect - again. Nothing. WTH?? Finally, just out of despair, I decided to crank the motor until the battery died. After about a solid 35 seconds of cranking (yes, I'd pulled the distributor and rodded the oil pump before hand), there were a couple of half hearted gas spurts from the pump. Hmmmm. Unhooked the inlet hose, put it in a bucket of gas, cranked it and firehose streams of gas!! NOT the result I'd had isolating the old pump and the 2 other new ones. When I let up on the remote starter, the white bucket of clear gas turned gray with drain back crap the pump had pulled from the tank, barely, when it was hooked up to the car. Blew air through the line back into the tank, installed a new pre pump filter, hooked it up, Shazam, a running GTX again. This combination of problems was uniquely confusing . . .for me at least. Finally figured it out. Had a new tank already on hand to put into the '67 Coronet I'm working on which will go into the X this weekend. Yee haw, beam me up Scotty.

Coronet 500

Thank You. The final resolution is so helpful to others and so many on any forum don't post it leaving questions to someone experiencing the same problem.

RacerHog

So So true Dan......
Thanks Don-Key-Diver for the awesome update.....

Archer

Donkey -

Ouch... It's always the last place you look.

Congrats!

Archer

donkeydiver

I've always found it frustrating to read through threads nearing conclusion only to find the, "l'll let you know" posts never happened. Was happy to do it on this thread. I've learned a lot just from reading posts on this forum regarding many topics and thought it was the least I could do. Thanks again.