Very Crappy Day, 914 Broke Down Options

[Britain Smith]

Well, I had a shitty day and to add to it my car decided that it was a good day to have issues. I was driving to the doctors office for my bum wrist and on a high speed onramp the car started to go slower and die. I coasted up the onramp and stopped right in the path of cars going 60mph. I was able to turn over the motor with it in gear to move it forward and then pushed it back out of the way. A tow truck guy who said he was a 914 guy, ended up pushing me off the highway using his rubber push bumper (I was a bit nervous).

I spent the better half of a hour on the phone with Brad try to determine what the hell happened. The car would turn over and it smelled like gas. It started up a couple of time for a few seconds and died immediately. To make matters worse, I had no tools on me and was in nice clothes. After going through every connection, switching the injectors around, looking for broken wires, checking EVERYTHING, I began to start switching out the relays in the engine bay. When I switched out the second one, the car fired up and ran like nothing happened.

So, my first question...what does the middle relay do on an early car? Also, what is the failure mechanism for relays? Do they die immediately or are they intermitant? Is there anything else I should check? The funny thing is, I just picked up the 1.7 injectors that lmcchesney sent me...thanks man! Unfortunately, I had no tools...that won't happen again.

-Britain

[ArtechnikA]

Also, what is the failure mechanism for relays? Do they die immediately or are they intermitant?

varies all over the map; this makes troubleshooting them so much fun !

a break in the coil wire will kill them instantly. unless there is an internal short or the break is inside the coil somewhere and decides to make contact again depending on the temperature, the size of the last pothole you just ran over, the humidity, the phase of the moon, and how late you are for the meeting you're trying to attend...

crappy contacts where they plug in can help them go intermittent. a common failure mode is that the switch contacts inside the relay (which i know you know is just a remote-control switch, but i'm mentioning it for those just learning...) get dirty from environmental factors, or pitted, from many thousands of little current arcs. those then work 'sometimes'...

or the coil develops high internal resistance just from age, and sometimes pulls the armature in 'almost' far enough. or makes contact and then gets tired and falls out in operation. or the little spring that's supposed to hold the contacts open when not energised gets tired or breaks and then it mostly won't turn off...

(i once chased a CIS-KE problem for two years and it turned out to be a tricko VW special dual relay...)

everything on a 30 year old car is suspect unless you personally have replaced it - electromechanical stuff doubly so ...