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My 1980 20r has a mechanical pump. Appears to be original. There is NO spacer between the head and the pump which is odd to me. The 20r pump is not the same P/N as the 22r pump and I want to know if they are interchangeable and what the difference is. Thanks.
Do you have a local chain auto parts store? If they're nice, they may unbox one of each for you to let you compare. What's the reason you can't buy the correct one for the truck?
Do you have a local chain auto parts store? If they're nice, they may unbox one of each for you to let you compare. What's the reason you can't buy the correct one for the truck?
im a parts snob and I accept it, I rarely use after market parts unless I consider them superior or an upgrade, or it is simply not available from Toyota anymore.. Toyota discontinued the fuel pump for the 20r but not the 22r. Every parts store in town offers the pump as an FDO which require payment up front and I ain’t doin that ha. I have a hunch the 22r pump works, I just wanted to hear it from someone who has tried.
I've never tried to see if it would work or not, but just comparing the pics they do seem to have some differences. Offhand I'd say probably not interchangeable. Parts numbers are different and that's usually a sign. On the other hand, the mounting flange & arm length & shape look VERY similar. The spacers look alike as well.
Something interesting on that page too. For both the pump & the insulator, they show "supersession" numbers, which I take to mean a later, possibly "improved" part that took the original part numbers place.
Searching the last highest part number (assuming newer part numbers would be logically higher) shows a later part. If you then check the "what this fits" tab, it shows the part also fits 22R's up to 1992(!)
So maybe the aftermarket pumps would work as well & your suspicion is correct?
so my local dealership parts expert got me in a 22r pump this morning so we could compare them. my truck was owned by a kid with no professional mechanical skills for years and he trashed it. completely destroyed the interior and just own right ruined a lot of things. I rescued it and have been slowly getting it back, I say all this because he did not use any oem anything for parts, which is why I believed the pump to be original to the truck but after seeing an oem 22r pump this morning, I believe my pump was taken off of a 22r and installed on my truck. they are identical. I used 22r gaskets and insulator when I reinstalled my old pump the other day so I know the base is the same. I made a home made vac drop test out of a brake bleeder gun and put it on my fuel pump, turns out I was wrong and the diaphragm was fine. I was getting fuel into the oil. I think maybe it was the janky Chinese carb the PO had on it with no FPR. I just installed a new weber 32/36 and a nice FPR and I hope that solves my issue. as for the fuel pump, im going with yes they are interchangeable.
I'm assuming you had a Chinese copy of the Weber 32/36 on it? Those things have been a plague for a while now, especially on Ebay. Despite anything wrong with the counterfeit carb, the lack of the FPR is the likely cause for the fuel in oil problem.
Those mechanical pumps are rated at 3 PSI minimum, 5 PSI maximum. The Weber 32/36 (even a bad Chinese copy of one) doesn't like anything over 3 PSI or they flood. I've even seen a genuine one have it's needle & seat overwhelmed by 3.5 PSI.
Good work on being a "parts detective", good info to know.
You pretty much have to be a parts detective for these trucks!
I agree on the aftermarket parts. I had my 83 break down on the side of the road, out of cell service in southern Utah after I had rebuilt basically all of it. I had learned enough about the truck at that point to be sort of educated in what to look for. It had the stock carb, and I checked out the sight glass: no fuel. Took off the fuel pump and a washer on the arm had sheared off, so the arm was just limp. I managed to rig it well enough to get me to a parts store. But that was a brand new pump from NAPA. Don't remember the brand.
The only difference I'd worry about is the arm contacting the pulley (can't remember what it's called) in the head. If it sticks out farther, you might have slightly higher fuel pressure, less far, less fuel pressure, but I'm not sure. Might still be within the correct range either way.
You pretty much have to be a parts detective for these trucks!
I agree on the aftermarket parts. I had my 83 break down on the side of the road, out of cell service in southern Utah after I had rebuilt basically all of it. I had learned enough about the truck at that point to be sort of educated in what to look for. It had the stock carb, and I checked out the sight glass: no fuel. Took off the fuel pump and a washer on the arm had sheared off, so the arm was just limp. I managed to rig it well enough to get me to a parts store. But that was a brand new pump from NAPA. Don't remember the brand.
The only difference I'd worry about is the arm contacting the pulley (can't remember what it's called) in the head. If it sticks out farther, you might have slightly higher fuel pressure, less far, less fuel pressure, but I'm not sure. Might still be within the correct range either way.
luckily I installed a sweet little adjustable fuel regulator beside my new Weber 32/36 and I put an inline 3 way Union that I can slap a small gauge in if I need to adjust it on the side of the road.
You pretty much have to be a parts detective for these trucks!
I agree on the aftermarket parts. I had my 83 break down on the side of the road, out of cell service in southern Utah after I had rebuilt basically all of it. I had learned enough about the truck at that point to be sort of educated in what to look for. It had the stock carb, and I checked out the sight glass: no fuel. Took off the fuel pump and a washer on the arm had sheared off, so the arm was just limp. I managed to rig it well enough to get me to a parts store. But that was a brand new pump from NAPA. Don't remember the brand.
The only difference I'd worry about is the arm contacting the pulley (can't remember what it's called) in the head. If it sticks out farther, you might have slightly higher fuel pressure, less far, less fuel pressure, but I'm not sure. Might still be within the correct range either way.
Speaking of parts detecting.....
Your story got me curious so I checked out NAPA's site to see what they had for the '83. They only list one mechanical fuel pump, Part # NNP B0044P, Line: NAPA Fuel Pumps. Price - $44.99 https://www.napaonline.com/en/p/CFPB...ndex=Universal
Wow! Yeah. And I think the little southern Utah town I found only had a carquest or checker or something. That pump lasted till I sold the truck though. Problem with Rock Auto is the shipping. I'll bet that $18 pump is right around $30 once shipping is added. Still cheaper than NAPA...
My experience has always been that NAPA generally caries higher quality parts than the other chain stores. But they're still an aftermarket parts supplier.
Apr 21, 2020 | 08:21 AM
