Engine dies while driving

[HotWat1]

I got a '75 2.0 a few months ago and have been bringing it back to form. It has no problems starting and runs well (no real stalling, sputtering, etc.). When I take short drives around the neighborhood no problem. Lately when I start more extended drives and getting to higher speeds, after about 10-15 minutes the engine dies (so far I've been able to coast to a safe spot). The fuel pump seems to have no power since I can't hear the usual "start up whine" when I turn on the accessories. I have replace the round relays in the rear board. Besides the fuel pump that may be causing this, what else should I be looking for??

[Dave at Pelican Parts]

Wires, wires, wires. One of the two fuses on the relay board. The ECU. The connections between the various wiring harnesses and the relay board. The relay board itself...

Brad Anders has a troubleshooting flowchart on his D-jet website, http://members.rennlist.com/pbanders . Bill Williams wrote up a procedure earlier about the fuel pump control system; this procedure is up on Tim Jones' 914 Fan site. http://www.914fan.net/fuelpump.html

--DD

[HotWat1]

Dave,
I forgot to mention that after a few hours of "rest", the car starts up and runs fine. I'm not very savvy on the electrical diagrams, so I may seem (and be) a little slow. I am trying to rule out some causes. Couple questions:
1. What color are the two fuses on the relay board? (mine has two red 16A fuses, but it seems that the back one to the fuel pump is suppost to be blue 25A???)
2. Since the two round relays (Power to the ECU, and Fuel Pump) on the relay board are new, can I rule them out as the problem?
3. Is there another fuel pump relay and were is it? (noticed it on the Pelican's parts list)
4. Is there a relatively simple test for testing the ECU to see if it has issues??
Thanks for the help

[jamcleod]

maybe it's a clogged fuel filter/fuel line. when they run OK at low rpm then poorly at high rpm, check fuel supply. the higher rpm requires higher flow and something if preventing the higher flow rate. but listen to DD first.

[Dave at Pelican Parts]

Originally posted by HotWat1
1. What color are the two fuses on the relay board? (mine has two red 16A fuses, but it seems that the back one to the fuel pump is suppost to be blue 25A???)

Check the relay board diagram on our site. I think it's the upper (front-most) one that is supposed to be 25A.

2. Since the two round relays (Power to the ECU, and Fuel Pump) on the relay board are new, can I rule them out as the problem?

Nope. New parts can sometimes be bad. If your headlights go up and down fine, swap those two relays with the headlight motor relays in the front trunk.

3. Is there another fuel pump relay and were is it? (noticed it on the Pelican's parts list)

The 1.8s used a different relay setup to run the EFI; on a 1.7 or 2.0 just those two round relays are needed.

4. Is there a relatively simple test for testing the ECU to see if it has issues??

Not that I know of. Usually you eliminate all other possible suspects, and then swap out the ECU--they rarely fail. Pelican does have an ECU tester that they can rent out; contact Customer Service to see what that entails.

--DD

[swl]

Dave's advise is as usual solid - do your trouble shooting logically and you will save time in the long run.

However ...

Since you say you don't get along well with wiring diagrams and your symptom are identical to mine many moons ago:
Replace the 25 amp fuel pump fuse and clean the contacts on the fuse holder.

I can't really explain why but corroded terminals on the fuse seem to be heat sensitve. Driving along and it poops out. Cool off (or bump the fuse while poking around) and it comes back.

And after that fails go back to troubleshooting the right way.