When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
you seen my threads trying to find one…even an alarm on ebay…same ole crap
Yes, I read your post. I figured it was mostly a quality issue, not just a plain old issue that they don't fit. I called Ecklers which showed the Airtex, but when they measured it for me it was the length of the Carter. I didn't ask the sales guy to check the p/n on it initially and didn't want to send him back to the warehouse a second time. So, my hunt continues.
Concerning your issue with ebay, if it was a specific seller, would you mind dropping me a PM with the seller ID?
The update/question of the day. So, the pushrod is now out. But, in pulling the backer plate, it popped of suddenly and the rod fell out. fortunately, I have old carpet under the car so it didn't get damaged. But, I'm not positive which end was cam vs pump. One end is very clean and flat with minimal variation in the appearance. The other end of the rod has some varnish on the shaft and the flat shows a ring of burnishing. Photos worth a thousand words. Sorry for the poor quality of the photos.
Is varnish is from oil in a guide for the rod? What end would that make it?
This end, very minor burnishing. The photo doesn't show well, but this end is a mirror like finish. The minor burnishing cannot be felt by hand.
Varnish end, more burnishing. The non burnished section is mirror like. And the burnished cannot be felt by hand.
Last edited by vince vette 2; Jul 13, 2021 at 09:48 AM.
I bought this one in march.. zero fitment issues on my 74. https://www.ebay.com/itm/373379054880
Looks to be the same as pictured above. when compared to the ac delco unit on the original engine they are the same dimensions with ports in same positions.
Last edited by augiedoggy; Jul 13, 2021 at 09:48 AM.
My guess is that Chevy changed the pump in 77. If you go to Inline at https://www.inlinetube.com/products/cxe7701 , the link Jebby sent to me, you'll see that fuel line is for 77 to 81. But for a 70 to 76 you have this https://www.inlinetube.com/products/cxe7001 . Clearly something changed. My guess is the length from the carb inlet to the fuel pump inlet fitting.
Going to most parts places looking for a fuel pump you see the same thing listed for 70 to 81. But, hunting around, if you check Parts Geek asking for a pump for an 80 the Airtex 41240 shows up and lists as fitting 77 to 81.
The Carter 6955 also shows up. But the photo they have does not look like the 6955 on Rock Auto or some other sites and not like what I got from Rock Auto. In the Parts Geek photo the bowl looks proportioned properly like the Airtex. And if you select it, it is listed as only for 77-81. I then put in for a 76 pump at Parts Geek just to see if the Carter pump would show up. It did not. My sense is that Carter changed the 6955 so it would also function with 70-76's but without regard for fit.
I'll leave it there. A lot of BS which just adds to what Interpon covered in his thread.
And I thought the mechanics of pulling and replacing the pump would be the hard part.
And the plot sickens. So, I called Airtex and the girl who answers says "Hello Carter products". Well Carter bought Airtex, but keeps shipping under the Airtex name putting Carter pumps in there. Now, if you go to RockAuto you can get the Carter M6955 for $18.96. But if you prefer to purchase that Carter pump in Airtex box it's yours for just an additional $4.83. What a deal.
Of course, the real issue is that Carter exists in name only also. The Carter tech support folks asked if I'd be willing to send some photos of the two parts so they can note the issue to their engineering group and possibly fix it - like that will happen. But I'm willing to play game. Who do I send the photos to? technicalhotline@firstbrandsgroup.com. So, we are obviously dealing with a holding company which is buying up makers of similar products and stripping down the quantity of part numbers to reduce costs.
Not that none of this addresses my immediate need of finding a fuel pump that won't require that I make my own fuel line.
Last edited by vince vette 2; Jul 15, 2021 at 08:38 PM.
The pump is on, car started, ran for several minutes, knocking sound is gone. Hate to say it, but it may have been what caused what I thought was the timing gear/chain noise, but at 90k miles that was due anyway. Thanks all for the guidance.
Some notes:
As for what pump to use - Based on input on another thread which I started just on the issue of the right pump to get, I used a Delphi MF0026. It matches the size and clocking pretty much exactly. Got it at Autozone. I did note that the pump housing is very close to the tip of one of the motor mount screws. They are separated by just 0.038". But I guess it must have been the same for the old pump.
I used the fuel line Jebby listed from Inline. Pretty close fit. It took a little hand bending but not bad. However, when done and torqued in the center section moved and is pressing against the front screw of the pump. Since the pump and the and line are both on the engine and only rubber hoses go from the pump to frame I suspect there wont be much relative motion between the line and the screw, but I'll watch.
If you have A/C plan to remove the belt adjusting plate that bolts to the block and water pump. If there's a way to thread the fuel line behind both it and the support rod that bolts to the A/C mounting bracket, I didn't find it. The support rod can stay in.
On the issue of using one of the pump bolts to hold the pushrod, it obviously works. But if you don't plan on removing the backer plate be sure to leave one pump screw tight on one side of the pump so the pump can continue to hold the pushrod up until you have the used the other screw to hold the pushrod. Otherwise, the pushrod may drop. I could not then get any grip on it to move it back up. Simplest solution is to just have a another 2" or so screw of the right thread pitch ready to go and lock it up at the start. I'm too lazy to look up the pitch right now, but suffice it to say it is not a fine pitch.
I still don't know what was failing on the old pump as it's movement is the same as the new. If I get a chance I'll have it x-rayed at work and see what was up.
Last edited by vince vette 2; Aug 1, 2021 at 06:28 PM.
Interpon, do you still like my previous post now that it says I'll have it x-rayed at work instead of X-rated at work originally. Talk about a Freudian slip.
Anyway, took it our a few miles. Runs OK. Starts much better.
On a sad note, the original tapping sound going way back to my thread on the timing chain replacement is back. My best guess now, it was not the chain, but always the fuel pump. As the pump got worse so did the tapping eventually becoming a flat out knocking. That knocking is clearly now fixed with the new pump. But the tapping remains. My best guess at this point is the following:
fuel pump was in the process of failing and causing some cam lobe wear
that was the tapping I heard originally coming from the timing chain cover
after changing the timing chain there was a definite reduction in the tapping for the next 40 miles or so - no idea why
Once the noise was back I did a better listen to the pump, finding a real knock listening to the actuator area
Changed the pump and the knock was gone, makes sense if a bad pump
But the tapping was also back, though nearly non-existent
Now the tapping is back clear as ever
Still no knocking
I think based on all this wear of the cam lobe makes sense, but what I can't explain is why the tapping would go away temporarily after the timing chain swap. Even though it took me weeks to do it, I can't think somehow enough lube got on the cam pushrod to quiet it.
But, here's where I am at - given a 90k mile engine which I plan to rebuild in any case, I think the time has come because if this tapping is something else, then ...
Question - Any short term risk driving with this ticking sound? Other that a worn fuel pump cam lobe, could it be anything major?
Hey Vince. I don't know enough about these fuel pumps to be able to answer your question but I have a shot in the dark thought. Any chance the fuel pump rod could be worn instead of the cam?
I really doubt its the fuel pump cam lobe worn. Seldom do those wear down. Why?
Think about the pressure or lack of, on the cam lobe from the fuel pump arm and spring. Can you or can you not grab a SBC fuel pump and force the arm downward with your bare hands?
Of course you can. So how many pounds of pressure is that?
How about the cam lifters with 300 pounds of spring pressure on the cam lobe? Yes, they will wear. Fuel pump cam lobe? No.
Besides, the tip of the pushrod is usually softer material to sacrifice itself instead of the cam lobe.
Your tapping sound is likely a loose rocker or header gasket? Pull the Valve Cover and observe.
Remove the fuel pump and gas line to the carb. Get a rubber fuel line and a container and gravity feed to the carb and start the engine. If the noise goes away its the fuel pump. If not you got bigger problems.
Didn't have any time to track down the issue this weekend, but am considering the advice here. I think the first thing I want to do is get a real engine stethoscope to see if there is any indication the sound is not coming from where I think. I'm also willing to let it sit a while since after both repairs the sound was gone but came back after the first or second drive. I want to see if that happens again.
