HELP: accelerator pump check valve/ retaining clip (1 Viewer)

[GJCruiser]

Just rebuilt 6/77 Aisin carb following Pinhead's excellent videos. Had a concern at one point during video and now an accelerator pump issue afterward. During the video, instructions were to remove retaining clip securing accelerator plunger inlet check valve ball. I could not identify a clip and did not remove anything before turning carb upside down only to have the check ball fall out.

Upon rebuild, following the video, it was stated the retaining clip holds the check ball in place. I simply replaced the ball as I found it and completed the rebuild. Now I have no spray from the output of the pump into the venturi. I cleaned all passages with wire and can force liquid through pump output.

Please, help me understand how either having no retainer clip over the ball or an incorrrectly placed ball over a clip I could not remove is the cause for my inop acc. pump. I will pull airhorn and attempt to photo what I'm seeing in the plunger shaft.

Thank you

 

[EWheeler]

Just rebuilt 6/77 Aisin carb following Pinhead's excellent videos. Had a concern at one point during video and now an accelerator pump issue afterward. During the video, instructions were to remove retaining clip securing accelerator plunger inlet check valve ball. I could not identify a clip and did not remove anything before turning carb upside down only to have the check ball fall out.

Upon rebuild, following the video, it was stated the retaining clip holds the check ball in place. I simply replaced the ball as I found it and completed the rebuild. Now I have no spray from the output of the pump into the venturi. I cleaned all passages with wire and can force liquid through pump output.

Please, help me understand how either having no retainer clip over the ball or an incorrrectly placed ball over a clip I could not remove is the cause for my inop acc. pump. I will pull airhorn and attempt to photo what I'm seeing in the plunger shaft.

Thank you

The ball is to act as a one way check valve from float bowl to acc pump bore, allowing fuel to flow from the bowl into the bore but not from bore back into fuel bowl. I am just postulating here, but if the ball is not held into it's proper place to act as a stopper for flow of fuel from the acc pump bore back into the fuel bowl, when you depress the acc pump pluger, the fuel will transfer back to the bowl (path of least resistance) instead of spraying into the primary intake bore.

 

[GJCruiser]

Attached is photo into bottom of accel plunger cavity showing small check valve. Is there a retaining clip there I'm not seeing? I may have to remove carb so I can dump both check valves and inspect bore between them for obstruction. I did that during rebuild. Still no output from aceel pump circuit into venturi.

 

[GJCruiser]

Ewheeler, good thought. I can understand needing to build/maintain pressure there. Do you see a retainer that I don't? I have tugged a hundred ways with needlenose and can't seem to remove anything.

 

[Pighead]

Attached is photo into bottom of accel plunger cavity showing small check valve. Is there a retaining clip there I'm not seeing? I may have to remove carb so I can dump both check valves and inspect bore between them for obstruction. I did that during rebuild. Still no output from aceel pump circuit into venturi.

View attachment 2960603

No, the clip is not there. The clip is sorta shaped like a small letter "e" and you put your hemostat jaws on the center of the e and twist to remove and install the clip. I cannot find a spare, so no pic.
Also, you should have 2 balls fall out of the carb when you turn it over. Sometimes those balls come in your rebuild kit. They are different sizes, big ball goes in the little hole and vice versa.

 

[GJCruiser]

Pighead, thanks for your reply. So either my carb did not have a retainer or it unknowingly fell out was was lost. I did not remove one. Did not have accel pump issues before rebuild. Either retainer was lost and is crucial or I have a block between two bores of pump circuit?

 

[Pighead]

When properly installed, that clip will not just fall out. Very possible that a previous owner did not replace it.
You need that clip.

 

[EWheeler]

Ewheeler, good thought. I can understand needing to build/maintain pressure there. Do you see a retainer that I don't? I have tugged a hundred ways with needlenose and can't seem to remove anything.

Like Pighead stated, clip is not present. It shaped like the lowercase letter e, as stated, and bi-sects the center of the bore there to keep the ball where it is supposed to live. The piece of the clip that bisects the bore is where you grab it with the hemostats to remove/reinstall, and it would be very easy to spot if it was there.

It seems the check ball retainer clip is still available from your local toyota dealership for under $5 likely.

Part Number: 2153831010

Thanks to this thread:

Carb rebuild question - accel plunger check valves and retaining clip

Stock Aisin carb from '83 Cruiser. Rig is out of service having the head rebuilt, figured I'd learn about the carb and rebuild it myself while I wait. Seemed to be going ok...except I've confused myself. I've lost track of which check valve/balls go where and some of the terminology is...

forum.ih8mud.com

I dont know if these changed through the years or not, but this is worth trying out due to the low cost.

 

[GJCruiser]

Interesting afternoon. Truck is running as well as it has been in 25 years. Here's the story.

Backstory: I rebuilt the carb because Jim C. last did it for me about 25 years ago. It was dirty and I had to pump the hell out of it first tiime every day. I rebuilt the carb to unlock the new problem discussed earlier in this thread.

Today: I took the carb back off engine so I could remove both check valves (balls) and reclean every passageway again. I put everything together on the bench and while refilling the float bowl from a can, I observed while manually stroking the pump plunger (I just love describing this ), there was fuel discharge only about 10% of the time. The output seems very dependent on the position of the plunger. Very finicky.

I dug the old plunger from the trash to observe it to be a little longer and completely different from the one in the kit that I used. The kit plunger had a rubber wiper and the one Jim C. used contained a leather wiper with a supporting spring. I cleaned it and reoiled the leather. Bench test with old plunger yielded strong consistent spray. I swapped out to the old plunger and accelerator pump and carb work as well as ever

I ordered the correct kit using the numbers on the airhorn. I just remember an old conversation with Jim C. where he emphasized the cruciality of a strong consistent output from the accelerator pump. Someone facing this problem may want to reuse the old leather plungers.

Regarding the retainer, it's possible a broken one fell out unnoticed (unlikely) or Jim C. did not install one. I can tell you it is not needed for the truck to run well. Thank you to those who verifed the absense of the retainer for me and for the part number. I will order one and pull the air horn once more. Thanks to everone-this forum continues to be the most amazing place!

Hope this helps someone in the future and thanks again.

 

[John McVicker]

Super good work @GJCruiser

 

[GJCruiser]

Well, I lied.

I went out this morning for a cold start test. Crank, but no start. No output from accelerator pump! I can pour a small shot of gas in primary venturi and truck starts right up. Took the airhorn back off and noted that leather plunger yielded samef inicky, intemittant output that the new one from the Keyster kit did yesterday. Careful observation of leather wiper does show very small cracks. I wondered if it was really worn out but I resoaked it in oil and put it back in. Worked much better this afternoon but I bet it will dry out overnnight again.

Need to source a new leather plunger and try that.

 

[EWheeler]

Well, I lied.

I went out this morning for a cold start test. Crank, but no start. No output from accelerator pump! I can pour a small shot of gas in primary venturi and truck starts right up. Took the airhorn back off and noted that leather plunger yielded samef inicky, intemittant output that the new one from the Keyster kit did yesterday. Careful observation of leather wiper does show very small cracks. I wondered if it was really worn out but I resoaked it in oil and put it back in. Worked much better this afternoon but I bet it will dry out overnnight again.

Need to source a new leather plunger and try that.

Options here:

Search: 4 results found for "accelerator pump plunger"

www.cityracerllc.com

 

[GJCruiser]

Thanks for the part help. NAPAOnline has an Echlin CRB24447 ($8.99) that they say should be right. Waiting for the mail.......

 

[Pighead]

So, what about the missing retainer clip?

 

[Bear]

"Regarding the retainer, it's possible a broken one fell out unnoticed (unlikely) or Jim C. did not install one."

----->Jim C. would not omit a part !

 

[Skreddy]

Attached is photo into bottom of accel plunger cavity showing small check valve. Is there a retaining clip there I'm not seeing? I may have to remove carb so I can dump both check valves and inspect bore between them for obstruction. I did that during rebuild. Still no output from aceel pump circuit into venturi.

View attachment 2960603

I’m going back to this post.
I may have to remove carb so I can dump both check valves and inspect bore between them for obstruction.

What do you mean “both check valves and inspect… between them”?

Check valve (ball bearing), retaining clip, done. Above the retainer is spring and accel plunger.

 

[GJCruiser]

Bear-I agree Jim C. would have never accidentally left out a part. But I am 100% certain I did not remove the retainer. I rebuilt the carb over a white garage towel. I'm also 98% certain it did not fall out in whole or pieces. As I was watching Pinhead's video exactly at the time he removed the retainer, I went "WTF"? "I don't have one". I turned the carb over and the ball fell out. I have intermittant pump function with both plungers. I don't have the complete understanding to know if the absense of the retainer is responsible.

Skreddy-Sorry, what I meant is that in an effort to find any piece of material I may have dislodged during cleaning, I removed both check valves (balls) and made sure I can send liquid through the passage between the two bores. I can. I am convinced there are no blockages anywhere. The plunger resides in the "input" side of the pump circuit above the spring and ball. From my understanding, there is a passageway into the smaller bore (output side) wherw the large ball, spring, and small plunger force gas out into venturi.

I recall Jim C. stating the importance of a strong consistent AP output stream as being vital to all starting concerns. At this point I have an unobstructed circuit, no retainer clip, and intermittant AP function with two plungers. I'll have to wait for mail to bring new leather plunger and retainer.

Thanks for reading.