1973 2.0L with stock D-Jet fuel injection.

About a month ago I had a strange occurance on the way to work. Engine ran smooth as usual until about 2 blocks away from the house when it cut out/in with no other symptoms. I pulled over, checked every connection on the engine that I could find, but nothing is obviously loose. Try it again, but the problem is still there so I stop for about 20 minutes at a store and when I come out and try it again it runs fine.

It has run fine ever since - even did 300 miles for the Route 66 Classic - but now the problem is back. My first thought was that it must be my home made resistor in the CHT sensor circuit, but removing the resistor didn't help. Completely bypassing the CHT sensor circuit with a new wire to the ECU didn't change it either.

I'm stumped This is not the kind of "buck" that you get at steady speed when the Throtte Position Switch is worn - it's a total shut down of the engine that can come right back as if some connection is vibrating loose and then reconnecting. Besides the CHT, what other components might cause this behavior?

Temperature sensor #2 located in rightside cylinder head is my guess. they have a way of acting like this. If it happens again and leaves you stranded jump the poles on the fuel pump relay board this will get you on your way.

Well that's the circuit I've been suspecting since I know from experience that if the sensor becomes disconnected, the engine shuts down. Which pins on the relay would I jump? If this made the problem go away it would confirm that the CHT sensor is bad. I didn't suspect the sensor itself because I used one that I thought was new when I did my rebuild a year ago.

Well that's the circuit I've been suspecting since I know from experience that if the sensor becomes disconnected, the engine shuts down. Which pins on the relay board would I jump? If this made the problem go away it would confirm that the CHT sensor is bad. I didn't suspect the sensor itself because I used one that I thought was new when I did my rebuild a year ago.

For sh*ts and giggles check your grounds, and fuse block, if dirty clean. Check your battery terinals, clean them and posts. Check where the ground cable connects on chassie, check the positive cable where it attaches at solenoid.
Check paddle connectors that they are tight and grease and oil free. Knock on wood, salt over your sholder, find four leaf clover and break out ouija board incase it dies altogether.

Before you do a damned thing... inspect the fuse box, all pins, and then clean/adjust every point anyhow.

Disco your battery BEFORE using a wire brush..

Fuel pump relay (my problem for a year)
Ignition switch (many times)
TS2 (obvious first choice)
Safety belt interlock crap (stealthy piece of shit)


M

Your trigger points in the distributor are also a failure point. They create the pulse train for the FI computor; no pulses no fuel.

I had a similar issue with my red 71. Every once in a while it would die and refuse to start. Open the air cleaner (carb) check for gas, ok. No start. Open the distributor, clean the points. No start. Do it again. Then it started. Did this too many times. I think its the points.

OK, time for Pertronix electronic points. This should solve the problem. NOT! Now I'm pissed. Removed the tach wire from the coil. Bingo! Started right up, ran good. I found that the tach wire as it ran on top of the engine was shorting out. I ran a separate wire to the relay board and cut out the old one. Problem solved.

Moral of the story: try disconnecting the tach wire and see if it runs.

Spoke

Just to add to redshifts advice. I had a similar problem just before I laid up the car. Turned out to be the fuel pump fuse. It wasn't blown but corroded. The intermittent part seemed to be caused by heat.

Try swapping out the voltage regulator. That's what cause a simular problem on my 73.

Hey Ernie,

No great insights to add to the above, but condolences (BTDT) and one more little tip. When you go checking fuses and connectors, a quick and effective way to clean them is with a pencil eraser. I had a bullet-type fuse (non-914) that caused my cooling fan to stop working. My radiator boiled over - no kidding - at the top of London Bridge. I was able to coast to water. Anywhere else and I'd have been SOL. Anyway, when I tracked it down, I just cleaned up the fuse and holder w/ an eraser and I was fine.


Good luck !

I finally figured it out - an intermittent connection within the relay board that affected the fuel pump circuit.

This was hard to track down because the engine would usually start and run, then die with no indication of why. Finally it stopped working at all and that allowed me to find it because I noticed that the fuel pump did not run for the few seconds that it is supposed to when you turn the key to the first position.

Besides swapping out relays for known-good relays, I tested with a voltmeter and found that I had voltage through the fuse on the relay board, but no voltage on the hot lead to the fuel pump. Swapping the relay board for another known-good board has fixed the problem.

Now if only I hadn't put the connector for the ignition harness on incorrectly (one pin off) and burned up my Pertronix Ignitor module I'd have a running car! As it sits I've got no spark and it's clear that I burned it up. Hopefully a new one will arrive in a couple of days and we'll be back on the road again.