1971 V6 Many Questions

Got the new one unloaded today. I started going over it and I have several questions. Lots of things missing and generally messed up.

I have an odd fire which I believe might be a 231 based on the valve covers and an HEI. I can't find the block serial number (despite a lot of time looking on the innerweb and all over the motor). It has the normal carburetor. The PO has an electric fuel pump. Any reason the mechanical wouldn't work (known issue)?

It has a jacked up el cheapo set of after market gauges. Would the normal location for the oil sender be down by the pump? Would the temperature send be in the intake?

It seems to have a later model CJ speedo as it has kilometers on it. Just temp and fuel in it. Any reason this won't work with the stock fuel sender and temperature sender?

It has heat. But no switch. Would the heater blower motor be more than one speed? Is multiple speeds handled by the switch? It's just two wires at the motor

Lastly, for now. Is this the correct light switch?

Thanks

 

Look in the Technical Index area at the casting numbers document - http://www.earlycj5.com/xf_cj5/index.php?pages/Tech-Index/

As I recall the block casting number is at the back of the engine, facing up, behind the intake manifold. Pretty sure these engines do not have serial numbers.

Other questions will have to wait for those more familiar with this year.

 

The oil sender is down by the pump housing near the oil filter connection.


The temperature sender is in the top of the intake manifold, passenger side rear.

 

Tim is correct , no Serial #'s . Buick called the engine VIN code #'s. Could be on the front of the block , DS or PS. Look at the Front of the DS head. If it's got a plug ,it's one one way of guessing that it's a 231. Different 'Model' engine vin codes #'s are in different areas. The Casting Block # for a NA Buick 231 is 25526109. Should be on The DS rear block, facing the right & reading up to down. Don't know why it has an electric fuel pump. If it was SFI & a turbo then it would be needed. Not on a NA, though.
Grant showed you were your sending units are.
Light switch is OEM , AFAIK.

 

I think I'll get a mech pump. The electrical with it's regulator is just extra mess. I'll get the senders to drop the lame gauge package. Thanks for the help!!

 

Electric has its advantages. The mechanical pumps seem to have quality issues, though a factory mechanical pump lasted a long time with no issues. The electric pump also has safety issues, which can be resolved with some added circuitry.

 

If memory serves, the 225 had cast timing marks while the 231 had a bolt on flange. Unfortunately, the covers are interchangeable, but that may be a place to start.
I also believe the rockers on the 225 are cast while the 231 had stamped arms.
Feel free to correct me if I'm wrong.
I used to have a great book on these (I think it was by HP) that had a lot of identifying criteria in it. I made the error of lending it to a friend and never got it back.

 

Looks like it's a 225. Probably out of a Buick cause its blue and older than my Jeep, 64-67. The reference I found actually has the number at 992326 instead of mine, 991503. I figure it is close or I am way off. Feel free to correct me. Thanks for the help

 

You are way off.

Read the PDF document in the Technical Articles area. I linked to the area above.

991503 is in there, and that's a Jeep Corp part number. That's a Jeep 225. Could not be more Jeep in origin.

 

this is a pic of the timing marks on my 225.

 

How I didn't figure out those were .pdfs I'll never know. I appreciate the patience and help.

 

I would love some education on this if you dont mind sharing more details….?

 

I sure there's lots about this online if you search.

In a nutshell, the electric pump should shut off in the event of a wreck or rollover. If it's wired to the ignition (typical and easy), the pump will run when the key is on, regardless of what else has happened.

https://www.bing.com/search?q=safety+and+electric+fuel+pumps
https://www.bing.com/search?q=electric+fuel+pump+rollover+switch

 

British sports cars often had electric fuel pumps, and sometime in the late 60’s started equipping them with an “upset switch”. This is a weighted safety switch that makes contact when the car is upright, but the internal weight shifts, cutting off the circuit, if the car rolls over.
Simple, but effective!
-Donny

 

Just to keep from flooding the forum I will ask another question under this thread. Where is everyone running the small 1/4" port on this fuel pump? Tee into the return line to the tank? Plug it off (if I understand it's function from the service manual this doesn't sound correct)? Thanks

 

That is the return line. It is to keep fuel flowing to reduce vapor lock problems. If you have a 71 the tank should have a return line connection. I don't know if the under seat tanks have the return line connection. You can also buy those pumps without the return line. Look it up on rock auto under a 1966 cj5 with the dauntless.

 

It's a return line tap. Typically the return will be smaller diameter than the feed to the carburetor.

As mentioned, the later fuel tank sender for the under-seat tank with a lock-ring has a connection for the return. You can also use it with the under-seat tanks.

JMO - don't worry about flooding the forum. That's pretty much the opposite of the purpose of the forum. If you have a legit question, start a new thread with a descriptive title.

 

Well, I have this pump installed so I will roll with it. The fuel filter has a return leg on it as well. I will tee them together and return them to the tank (which has a return in it, it's not the under the seat one). Thanks

 

If I also had the 3-port filter, I would cap the pump end and just use the filter return. The filter has an orifice in it that's lined up with the nipple that needs to be level. The orifice returns a metered amount of gas to the tank, and it needs to be at 12 o'clock. I presume the pump works the same. Seems unlikely the system was designed to work well with twice as much fuel returning to the tank.

 

Will do.