maxidyne with no torque

[6368]

I"ve bought a 1987 Rd  with an em6-300 Back around the first of the year.  It doesn't pull down low  like it should.   it has OK power if you can keep it above 1700 rpm.  But that ain't easy to do with a 6 spd.   Before i dig into it i want to verify that it has the correct injection pump on it. It has a 313GC5163p2.  I  don't (yet) have a tune-up specs book for engines that new. So i was hoping someone here might have that info for me. Thanks

[j hancock]

Don't have an 1987 book but that is a good number for a 1986 EM6-300.

[85snowdog]

Look at the number on the puff limiter relay valve.  What you describe is exactly how my R models perform with a "3x" or a "CX"  relay valve on.

A EM6 should have a "5x"  you could even put a "6x" on it. 

The part #'s for them are easy to decipher. 

691GC218CP6X  .   The higher the number and X , the lower the rpm to get fuel, but the more smoke . Remember these are mack part #'s , not volvo. 

I have done a lot of experimenting with different relay valves, and found there is a big difference between them. 

There is lots of good info on relay valves and setting the rack limiting cylinders up on here. 

The first pic is a "CP5X"

the second pic is a "CP6X"

the third was the part # for a "3X"    

 

 

 

 

[fjh]

We used to put the  P10  on everything  v8 to six cyl if its still available! as it was easier and cheeper to stock just one relay! 

[6368]

Today verified correct injection pump and a p8 relay valve. Next i think will  plug air line to relay valve and see what difference that makes. If it makes a difference then i will check the shimming of the puff limiter.

[mrsmackpaul]

I had a recent problem the same as this and found the air line to the relay valve had worn thru in one spot 

She drove like a race car when fixed LOL

 

Paul

[6368]

Plugged the air line feeding the relay valve and she runs much better.  Now i need to determine if the relay is messed up or the puff limiter is shimmed wrong.  Didn't have that much time today.

[85snowdog]

Thanks for the updates.