Car never ran better - THEN!, Seems when hot there is no low end power Options

[ctc911ctc]

'74 2.0 - 25K miles

It has been a very long journey. I, with my 17yr old son who is now 21, rebuilt nearly every system including the Engine and Transmission (a nod to Dr. Evil !! ). My son and I have learned a great deal, however, this one has me stumped.

The car runs terrific and is strong, smooth and a joy to drive, today I took it around the Lakes here in Arlington MA and at the end of the drive there is a hill with a red light - I caught the red. I waited as the button pushers jaywalked (after they hit the button) and then I waited some more with the crosswalk signs blinking and no one crossing.....sigh

OK, there is the green and I ease out the clutch and apply a little gas AND nothing...... nearly idling. I then bury the gas and the car stalls.......and since this is New England everyone starts beeping and yelling - so I get the flashers on and people go around me.

I wait another light cycle and get the cars started by pumping the gas and keeping it running over 1500, once it started moving it ran fine. It is almost
as if there was zero power below 1500, though when the car was rolling everything worked as you would expect. When the car is cold the low power is as normal as a 90HP engine can be. The temp of the car is about 2/3rds deflection of the center console temp gauge.

I am thinking all sorts of complicated thoughts.......head temp sensor is sending weird signals to the Bosch controller OR when super hot the vacuum system starts leaking, etc.

So, I thought I would start here - any ideas teeners???? Keep me sane and guide me to the light!


CTC911CTC

[ctc911ctc]

**********UPDATE**********

First, big thanks to R_Towle, he has been sending me ideas and assisting with the troubleshooting. Got me to stop thinking about what could be wrong and focus on the basics. Thanks Rich.

We eliminated Electric and focused on fuel, this thread has some of the debate within. I then decided to move the pump away from the furnace (it was directly in the way of the heater dump valve) and moved it to the starboard side of the firewall. I used an Evil-Fuel mounting bracket and also bought an Evil fuel filter and an exchangeable filter insert.

THEN - after all of the connects were on the devices the chain of lines and size changes got to 2 feet long, I thought I could mount them side/side and it would fit,,,,,,sooo,,,,,,I decided that I would bend some soft brake line for the fuel to move from the filter to the back of the pump......I used to be pretty good at bending EMT conduit........this was harder

After a while of playing with this I thought if I ever got this done, I would not be able to write a proper note to the next owner as to why I did this........many times I think about adding notes of apologies within my barely adequate fixes...... (IMG:style_emoticons/default/dry.gif) (IMG:style_emoticons/default/dry.gif)



.....SOOOOOO, I dropped back and put a new but plastic fuel filter on the low-pressure side....... hhhhmmmmm, perhaps a french horn could be.............

A few years ago I welded platypus bills on an old pair of vise-grips which is my fuel shutoff valve. I released the Platypus and let the fuel flow - had a few leaks.....sigh.....where are those nut drivers???? Got the fuel flowing nicely, no leaks now........

Rich instructed me (thanks again Rich) to put a pressure gauge on the rail (I installed a very nice brass access next to the rail and screwed the pressure gauge into the mix.

The car started right up, went to 29lbs immediately, and ran well. Next, I turned the car off to double-check for leaks and I noticed the pressure went to zero in a few seconds. Oh yea, no leaks!


There is a great deal of experience with this forum about this problem that often the fuel pump internal check valve which is in place to prevent vapor creation is the culprit.

Buying a new fuel pump - I am also buying a new regulator. Mine is 50 years old.

I also would like to buy a steel small fuel filter 5/16 to 5/16 - any ideas?

Stay Tuned!