Changing a Mechanical Fuel Pump - '78 New Yorker

[shooter65]

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[CBODY67]

I see the power piston is up, so that spring is still there, which is good. What I also see is the existence of the ELB throttle position transducer on the rh side of the carb.

Might be that the secondary spring is broken, as it is small gauge wire? Or somebody did not know how to adjust it and figured that if the air valve was open, it effectively made for a manual secondary 4bbl?

Thanks for the pictures!

CBODY67

 

[rsbolin]

Your secondary air door is too loose. Do you know how to adjust the door with out unwinding the spring?

Cbody and boydsdodge.

Yes. Tension on the larger screw while turning the smaller, inner screw. Don't release until you feel there is no tension on the screw. Then tighten the larger screw.

Having said that, it appears to me that spring has sprung. It not like this three weeks ago.

 

[rsbolin]

I am most likely going to have to remove the carb and take to The Carb Shop here in Greenville, SC. The car was there for three weeks while they did all of the fuel system work, including a rebuild of that carb.

 

[CBODY67]

The "official" method to adjust the secondary air valve tension spring is to use a Carter special tool for such. When I had the TQ 9801 on the '67 Newport, I was trying to get the air valve tight enough to diminish a hesitation when the valve opened. I had been using a wide slot screwdriver to turn the outer ring and a thin slot screwdriver to do the middle screw.

With the spec'd adjustment tension, a bog when the air valve opened, no matter what. Probably needed to restrict the vac actuator's loss of vacuum, ala Rochester QJet? Anyway, that's how I discovered the fragility of that adjustment spring!

The Carter tool simplified that a bit, just needing the smaller slot screwdriver. BUT you can make that took, pretty much. Find the diameter of the larger item and get a piece of tubing that diameter and about 4" long. Then file one end such that there are two resultant tangs to index with the outer ring on fhe adjustment ring. Then deburr both ends for good measure. The original tool had a handle on each side of the non-tanged end, for ease of use, but you can just turn the tube instead, by hand. Still a two-handed operation, but not a tricky as with two screwdrivers.

Enjoy!
CBODY67

 

[Mbaird]

I doubt its the fuel pump. If the fuel pump was bad it would have issues starting hot or cold.
Next time it wont start spray a little starting fluid in the carb. If it starts right away then it is most likely the accelerater pump. If it doesnt start try holding pedal to floor while cranking. If it starts it was flooded….my AFBs tend to leak down fuel while sitting for some reason and over fuel the engine. I can just hit the key after a week and it fires right up … no pump shot required. Not correct but it works.

 

[Ripinator]

I am most likely going to have to remove the carb and take to The Carb Shop here in Greenville, SC. The car was there for three weeks while they did all of the fuel system work, including a rebuild of that carb.

Recently, I went through the same nightmare you are going through. I had all the same symptoms you experienced. I replaced the tank, sender, fuel pump, all the fuel lines from the tank to the pump and installed a new fuel filter (twice). In the end, my fuel pump pushrod was almost 3/8" too short. I found a U.S. - made rod from 440 Source, removed the allen-plug in the block (under the fuel pump) and installed the new rod (and smeared Comp Cams cam lube on both ends). All is now sweetness and light. The car runs like a raped ape.

One more thing: If the car sits for several days / weeks, it will take a lot of cranking to get fuel from the tank to the carb, before she will start. This is normal.

BTW, I love the upstate Greer / Greeneville area a lot!

 

[rsbolin]

Recently, I went through the same nightmare you are going through. I had all the same symptoms you experienced. I replaced the tank, sender, fuel pump, all the fuel lines from the tank to the pump and installed a new fuel filter (twice). In the end, my fuel pump pushrod was almost 3/8" too short. I found a U.S. - made rod from 440 Source, removed the allen-plug in the block (under the fuel pump) and installed the new rod (and smeared Comp Cams cam lube on both ends). All is now sweetness and light. The car runs like a raped ape.

One more thing: If the car sits for several days / weeks, it will take a lot of cranking to get fuel from the tank to the carb, before she will start. This is normal.

BTW, I love the upstate Greer / Greeneville area a lot!

Thanks, Ripinator, for the reply. I have lived in the Upstate since May 2005. It is a wonderful place to live year-round. Uptown Greenville as well as Travelers Rest are so nice.

Is 440 Source a member of this forum? Do you have a means to contact?

Also, I have a concern about driving the vehicle. I have a bit if steep driveway. If I do not give that old girl a high rev with my foot on the brake, she will die. It is concerning. I bought her to be my daily because of the mileage, 17,705 miles at purchase, and the great condition from sitting inside of collectors facility.

Believe me, I love everything about this car. It would be great to be able to give her legs some good runs. I am just too afraid to do it.

Ron

 

[rsbolin]

The "official" method to adjust the secondary air valve tension spring is to use a Carter special tool for such. When I had the TQ 9801 on the '67 Newport, I was trying to get the air valve tight enough to diminish a hesitation when the valve opened. I had been using a wide slot screwdriver to turn the outer ring and a thin slot screwdriver to do the middle screw.

With the spec'd adjustment tension, a bog when the air valve opened, no matter what. Probably needed to restrict the vac actuator's loss of vacuum, ala Rochester QJet? Anyway, that's how I discovered the fragility of that adjustment spring!

The Carter tool simplified that a bit, just needing the smaller slot screwdriver. BUT you can make that took, pretty much. Find the diameter of the larger item and get a piece of tubing that diameter and about 4" long. Then file one end such that there are two resultant tangs to index with the outer ring on fhe adjustment ring. Then deburr both ends for good measure. The original tool had a handle on each side of the non-tanged end, for ease of use, but you can just turn the tube instead, by hand. Still a two-handed operation, but not a tricky as with two screwdrivers.

Enjoy!
CBODY67

It appears to me that the tension on that spring is gone. I do not know how that happened since I have only put about 17 miles on it since I brought it home from the carb shop.

I presume that means removing the carb and finding a way to re-attach that spring. That cannot be too much fun.

I am not opposed to buying one of those Carter special tools if they can even be found.

 

[Boydsdodge]

I wish you were closer, Id love to get the carb set up and do some checks on the car. Lots of Thermoquad info here.

(Chrysler) Imperial Fuel System Repair Information

 

[CBODY67]

That air valve spring is a bit too fragile, compared to other similar springs on other 4bbls, from what I can tell. Carefully remove the small screw which holds the tension on the larger item. Put it on a piece of duct tape for safe keeping. Then, as I recall, you can remove the larger item with the two tangs on its inner diameter, which tensions the spring. With that out of the way, either the spring will come out with that part or it will slide off its shaft easily. You'll probably find the end which broke off inside the cylinder it stays in.

THEN, get a piece of duct tape and cover the orifice on the vac actuator, which governs how fast the air valve opens (as on a Rochester QJet), then punch a smaller hole in it to slow the opening of the air valve itself.

On my 9801, if the spring was adjusted to specs, there was a hesitation when the air valve opened. I adjusted the spring to seek to delay the opening, which apparently put too much tension of the spring, causing it to fail. At least that's my theory . . .

Enjoy!
CBODY67

 

[Big_John]

That air valve spring is a bit too fragile, compared to other similar springs on other 4bbls,

^This^

I've seen TQ's that the spring was adjusted wrong and the spring was destroyed. Many years ago, a friend's son had a Dart with a TQ where the spring had been over adjusted.... There was no going back and the car ran like crap. He had "mechanics" look at it and they just made it worse. I looked at it and put a rubber band on it until he could get it fixed right... That actually worked surprisingly well for a temporary fix.

 

[rags]

It appears to me that the tension on that spring is gone.

could just check to see if the adjustment screw was not locked down. put a flat blade screw driver in the adjustment screw and try turning it counter clockwise. takes a moment and costs nothing. when i did them i was able to use two screw drivers together to set the adjustment then lock the collar. there is a company that has the tool: Thermoquad Air Door Adjusting Tool

 

[Ripinator]

Thanks, Ripinator, for the reply. I have lived in the Upstate since May 2005. It is a wonderful place to live year-round. Uptown Greenville as well as Travelers Rest are so nice.

Is 440 Source a member of this forum? Do you have a means to contact?

Also, I have a concern about driving the vehicle. I have a bit if steep driveway. If I do not give that old girl a high rev with my foot on the brake, she will die. It is concerning. I bought her to be my daily because of the mileage, 17,705 miles at purchase, and the great condition from sitting inside of collectors facility.

Believe me, I love everything about this car. It would be great to be able to give her legs some good runs. I am just too afraid to do it.

Ron

Ron:

Here ya go:

Fuel Pump Pushrod - New-440 Source

 

[rsbolin]

could just check to see if the adjustment screw was not locked down. put a flat blade screw driver in the adjustment screw and try turning it counter clockwise. takes a moment and costs nothing. when i did them i was able to use two screw drivers together to set the adjustment then lock the collar. there is a company that has the tool: Thermoquad Air Door Adjusting Tool

rags,

That inner screw is turning freely. No tension whatsoever.

 

[rsbolin]

I wish you were closer, Id love to get the carb set up and do some checks on the car. Lots of Thermoquad info here.

http://[URL]https://www.web.imperialclub.info/Repair/Fuel/index.htm

[/URL]

Boydsdodge,

You bet I am willing to pay good money for someone that know what to look for and to fix this issue for me.

All watching this forum, and this topic, keep that in mind. I will pay good money, and within reason the travel, to have someone come to my garage and give this fixed for me.

 

[rags]

No tension whatsoever.

then it's "game over." if the spring breaks or otherwise comes undone it falls into the bowl. it would be possible to feed a new one in through the hole, but the reality is that it should be disassembled, inspected and serviced by someone with experience. thanks for the reply.

 

[rsbolin]

then it's "game over." if the spring breaks or otherwise comes undone it falls into the bowl. it would be possible to feed a new one in through the hole, but the reality is that it should be disassembled, inspected and serviced by someone with experience. thanks for the reply.

rags,

does this mean I have to source a new thermoquad? would it be less costly to source a new/rebuilt than to have someone disassemble, inspect, and rebuild?

Ron

 

[rags]

does this mean I have to source a new thermoquad?

absolutely not. if i read correctly, you just had the carb serviced by a shop. is there no warranty? have you contacted them? would you want too?! as i and @shooter65 and anyone else here would suggest, there is @Dana at woodruff carburetor specialties. Carburetor Restoration in Youngstown, OH | Woodruff Carburetor Specialties . no doubt you could message @Boydsdodge and ask if he would be willing to service it for you.

would it be less costly to source a new?

not likely, but it could be more timely. i view anything mass market rebuilt as diseased meat. if you didn't know already, this is danas avatar:

 

[Boydsdodge]

I would be happy to help gratis. Issue is, I am up in Toronto, Canada.