Uphill running issue with my '64

I just got my new, dual straight back exhaust installed two weeks ago and have had the same issue happen since that time.

My van had a problem both the day I drove it home and then today. While going up a steep climb and going somewhere I believe is 65-70 (speedo does not work) the van felt like someone jammed a bananna in my tailpipe for just a split second. Almost like a gust of wind hit me, but I could feel it through the entire van. I can't say that it backfired, as I didn't hear any audible sound (although I had all windows down with the radio on.

A master mechanic I saw today suggested a timing issue off hand. He had also told me previously that he might need to help me adjust the mixture once my formerly hole ridden exhaust was replaced (it was dialed in based on a hole at the manifold.)

If helpful to note, it seems that she is burning up fuel rapidly. I also would swear she started to smoke for a split second yesterday shortly after getting down the road, but I could never find any hint of smoke in the DH or anywhere else and drove it a ways afterwards. Carb is brand new 4 barrel with maybe 100 miles on it.

It seems to idle nicely and goes down the road well. It was only under load while giving it more gas that it "hit the wall" and seemed to have no no power and jerked.

I do own a timing light that I picked up recently, but I've never used one or been taught how to do so. Thanks for the help.

check the tube to the vacumn advance for splits or cracks. Sometimes just cracked right it can collapse on itself. Just someplace to start.

Remove the exhaust & drive it ?/ may be a colapsed internal pipe or muffler?/

also if points distributor- look @ them or better yet check with dwell meter.

Twinpilot001 wrote:Remove the exhaust & drive it ?/ may be a colapsed internal pipe or muffler?/

also if points distributor- look @ them or better yet check with dwell meter.

Matt, no plans to remove the exhaust. The entire exhaust was suppossed to have been replaced. Checked vac tube just now, tight and new. I replaced it after purchase in place of melted aquarium tubing that was in place...

Hei, no points.

I cant remember if you are running the 350th or the 700 ? just wondering if the tranny isnt kicking down right?

Digz wrote:I cant remember if you are running the 350th or the 700 ? just wondering if the tranny isnt kicking down right?

350/350. I had the governor replaced when fixing all the leaks as the mechanic noted that it was shifting too quickly, something I also had noticed. I can't recall if he played with the tv cable or not? I know it was mentioned and I believe I have one (seems it is on the right side of carb when facing the doghouse?) I'm pretty sure he adjusted it and it's all the way out? if that makes sense.

I still think it shifts too quickly from first to second. Haven't paid attention to the other shift points. He also checked the vac advance and I think we replaced it with the most ideal setup. Need to find my paperwork.

Best way I could describe the running issue was a big "miss" in the running condition. Again, only under hard load. Why would the hard load affect the kickdown? It should go into lower gear when having to climb or into overdrive if I had a 700?

yeah if it was a 700 and wasnt kicking out of OD it would lug a little. But re reading ,, you may just be up against getting the carb tuned in right if its that new. Falling flat I would think it's either going to be ignition or fuel. Just have to eliminate the possibles one at a time. If your running at those speeds regularly with a 350/350th I dont think your going to be passing all the gas stations anyway.LOL Good luck with it Laz , I'll bet it isnt anything to serious tho.
Just for grins n giggles check the plug wires, I ran into that awhile back. had 1 loose on the cap , put a miss in it accelerating hard and acted a little flat at higher speed.

I had a similar issue with the wiki-van this summer. Hesitation only under load, especially going up hills. It was getting worse and worse. After doing through all kinds of heck, Including replacing fuel pump, a different carb, all the rubber hoses in the fuel line, checking timing, etc, nothing seem to remedy the problem, I finally discovered a fix.

I was experiencing some blockage at the pickup inside my fuel tank. Sediment had stopped up the inlet of my fuel. I disconnected the fuel line at the fuel pump. I opened the gas cap. I put my mouth on the rubber hose (the one going to the fuel pump, coming from the tank, and blew into it hard. I kept blowing until I heard bubbles in the fuel tank. I did this several times, and then put everything back together.

This is a way to 'back-blow' the fuel line and clear any built up sediment away from the inlet of your fuel line inside the gas tank. I suppose you could do this with compressed air too. I simply used my own lungs.

It remedied the problem and I have not had an issue since.

Is it a permanent fix? No. I will eventually have to drop the tank and clean it out. It did fix it temporarily, and I have not had the problem for 2 months of daily driving now. It also helped me to positively identify the problem so I can fix it later.

You can try this remedy, it is easy and costs nothing. If it fixes it, you know you have sediment in your tank that you can take care of at a later date. If it does not fix it, at least you know that crud in the tank is not the problem.

kookykrispy wrote:I had a similar issue with the wiki-van this summer. Hesitation only under load, especially going up hills. It was getting worse and worse. After doing through all kinds of heck, Including replacing fuel pump, a different carb, all the rubber hoses in the fuel line, checking timing, etc, nothing seem to remedy the problem, I finally discovered a fix.

I was experiencing some blockage at the pickup inside my fuel tank. Sediment had stopped up the inlet of my fuel. I disconnected the fuel line at the fuel pump. I opened the gas cap. I put my mouth on the rubber hose (the one going to the fuel pump, coming from the tank, and blew into it hard. I kept blowing until I heard bubbles in the fuel tank. I did this several times, and then put everything back together.

This is a way to 'back-blow' the fuel line and clear any built up sediment away from the inlet of your fuel line inside the gas tank. I suppose you could do this with compressed air too. I simply used my own lungs.

It remedied the problem and I have not had an issue since.

Is it a permanent fix? No. I will eventually have to drop the tank and clean it out. It did fix it temporarily, and I have not had the problem for 2 months of daily driving now. It also helped me to positively identify the problem so I can fix it later.

You can try this remedy, it is easy and costs nothing. If it fixes it, you know you have sediment in your tank that you can take care of at a later date. If it does not fix it, at least you know that crud in the tank is not the problem.

Thanks, Kooky. Good advice. Interesting think is that my wife's car was having the same problems when we first got it. Smoking under load and then breaking down. Fuel injected '87, but still fuel related all the same. Re-lined her tank and no issue since (after months of problems.) My tank was supposedly re-lined by p.o. Carb was recently replaced due to gas seaping out, so maybe garbage is in the entire line?

I did not notice this issue before replacing exhaust (although it backfired audibly when letting off the gas before replacement). Perhaps the problem existed and there wasn't enough pressure in the system with a leaky manifold to make the issue surface? Or, it was so darn loud I wasn't hitting 70 to make it happen? Thanks for the help.

donivan65 wrote:You need to put a clear plastic fuel filter TEMPORARILY in the fuel line between the fuel pump and carburetor and watch the level in the filter as you accelerate,,,,,,see if the level gets lower the faster you go and that would be you are not getting enough fuel to the carb under a heavy load,,,,

Thanks, Don. I've got a brand new one on hand. I'll get it worked in and see what happens. Do I need to actually drive or will it work the same in the driveway?

Digz, I snugged up the caps on the plugs when I checked the vac line. Seemed to have no play.

donivan65 wrote:You need to put a clear plastic fuel filter TEMPORARILY in the fuel line between the fuel pump and carburetor and watch the level in the filter as you accelerate,,,,,,see if the level gets lower the faster you go and that would be you are not getting enough fuel to the carb under a heavy load,,,,

Don, good point. I actually did just that, I have a clear plastic filter just prior to the carb... and during the time I was having the hesitation problem the clear filter was only getting about half full, even at idle.

After back-blowing my fuel line, now the filter is almost all the way full... and the van runs good, and has had no problems for a bout a month now. I know there is still some crud floating around in my gas tank, but I'm not too worried about it. I will fix it later... or maybe re-seal my spare tank and swap them out. The van is running real good for now!

I guess I should replace the plastic inline filter with a steel one now?

donivan65 wrote:You could be running out of fuel,,,,is there a fuel filter inside the carb? It could be vapor lock,,,,you could be running out of spark,,,,coil breaking down,,,does that HEI have 12 volts to it and not hooked up to the 6 volt resistor in the wiring loom?

Don, forgive my ignorence, but I'm not sure on those questions. My carb was replaced with an identical Edlebrock 4 barrel. The old one did NOT have a filter inside the main inlet where the fuel line enters the carb. It was leaking out and it was checked at the time. I don't know enough to know if that is an optional things or something that is different for each carb.

As far as the HEI wiring, I need guidance on checking that one. Don't know that this is relevant, but when I turn on my signal when idling, the voltage drops back and forth between 11-12. Not sure if it happens when running down the road.

the HEI needs a minnimum of 8 volts to opperate properly, I have seen them run with less.

You need to do a little more indepth diognosis of what is actually happening at the time this problem occurs because it could be one or any combonation of 147 things.

Like the typical wire breaking at the pickup coil in the hei system. The way to test that is to have a hand held vacuum pump on the vacuum advance pot and slowly pump up the pot with engine idleing and look for just the right spot where the engine begins to stumble or stall.

All of these sugestions are good possabilities but more specific diagnosis is needed otherwise you could spend all month chasing your tail and spending money where you didn't need to.

M1D

one other thing problem that the hei dist had was
the wiring to the pick up coil in the dist breaks
contact when the vacumn advance is applied and
caused the ignition to temporally shut off, causing
a studder and sometimes a backfire, unhook the vacum
advance and see if the problem goes away, if so I would
replace the pick up coil in the dist.
one thing to remember, only try one change at a time to
see if your problem changes or goes away.

Didn't have time to try anything yet as the van was loaded down and "working" along with me. I can confirm that it has audibly backfired since the new exhaust was installed. My wife failed to mention (until today) that it happened on her watch last week. I drove around today and no issues, but again, it's only happened to me on uphill climbs at Interstate speeds while under acceleration.

I will remove the advance first, since that's the easiest, and see if it stumbles going uphill again. Next will be Don and M1's suggestions.

If you disconect he vacuum advance hose and go for a road test as panelmanrd said then you won't have the do the test I recomend because they are both checking the same thing.

Sorry Don I was talking metric, like on the Pontiac Baumont. I think with todays exchange rate its only 99 things US.

M1D

Lazarusvan wrote:Didn't have time to try anything yet as the van was loaded down and "working" along with me. I can confirm that it has audibly backfired since the new exhaust was installed. My wife failed to mention (until today) that it happened on her watch last week. I drove around today and no issues, but again, it's only happened to me on uphill climbs at Interstate speeds while under acceleration.

I will remove the advance first, since that's the easiest, and see if it stumbles going uphill again. Next will be Don and M1's suggestions.

My van was backfiring too, experiencing very similar symptoms to what you are describing... before I back-blew the fuel hose. You can try that too... it just might fix your problem. I know it sounds hokey, but it worked for me

kookykrispy wrote:

Lazarusvan wrote:Didn't have time to try anything yet as the van was loaded down and "working" along with me. I can confirm that it has audibly backfired since the new exhaust was installed. My wife failed to mention (until today) that it happened on her watch last week. I drove around today and no issues, but again, it's only happened to me on uphill climbs at Interstate speeds while under acceleration.

I will remove the advance first, since that's the easiest, and see if it stumbles going uphill again. Next will be Don and M1's suggestions.

My van was backfiring too, experiencing very similar symptoms to what you are describing... before I back-blew the fuel hose. You can try that too... it just might fix your problem. I know it sounds hokey, but it worked for me

Kooky, not hokey at all. I'm all too familiar with fuel related issues after months of getting my wife's vintage '87 vehicle back on the road. I have an issue with messing with fuel lines. My first project was to attempt to remove a funky fuel filter setup. Everything went well until I got a siphon going and dumped most of my tank on the garage floor. I was a perfect candidate for a human Molitov Cocktail.

I did pull the vac line to the carb, went up the hill, and backfired twice. One variable eliminated.