rgare

I own a stock (original fuel injection) 74 1.8 914, it was my first car and for many years my daily driver, but then one day it wouldn’t start. I had another car and a fiancé so I let it sit in the garage. My fiancé became my wife and four kids and tens later it’s still in the garage. So now I’m fixing it. But I’m stuck, and I could use some help. The car doesn’t start at all.

This is what I’ve done.

Fuel: I drained the gas (yes I let it sit in the tank for all those years) took the tank out and had it cleaned and coted. Sent the plugs out and had them cleaned, new seals, flow tested and repaired (one of them leaked down)

Fuel Injection: I have a pressure gauge inline, just before the driver’s side fuel rail (under the air box). When I crack the engine the gauge reads around 60 psi and then drops to around 10psi. I’ve check the injector’s connection with a circuit test light and the light pulses as the engine cranks. Pull the sparkplug and there is faint smell of fuel.

Based on this I think the fuel system is operational

Ignition

New: Sparkplugs, points, coil and condenser. When I turn over the engine I get a good spark jump from the plug wire to the case. Plug wires are old but show very little resistance. Plug wires are plugged in according to diagram from repair manual.

Based on the fat spark I think the ignition is operational.

Head temperature sensor: I removed this from the car and tested resistance. Measured 1.7K at 70F. Put the sensor in the freezer for around 10min. Measured 3K ohms and then rapidly decreased to around 1.7K. Manual says that sensor should read between 500-2500 ohms, and should be at 2500 ohms at 68F. Is the sensor bad?

I can’t really think of other things to test. Every so often I charge up the batter so the car cranks well, but not even a sputter of a start.

Please give me some ideas; I’d really love to get her started again.

nowlings

I own a 74 1.8 with original injection as well. Did you check electrical connection (plug connection) at the air flow control box? Based upon my own experience with the cht sensor....I'd replace it. They are not too expensive and they seem to go bad about every 3+ years or so (at least mine have). You may want to look at the spray pattern from the injectors to make sure you are getting a nice spray of fuel. Also make sure no massive vacuum leaks, but it should at least sputter even with a bit of vacuum leaks.

Peter Zimmermann

https://rennlist.com/forums/914-914-...-74-1-8-a.html

For your ECU check/repair be sure to use Specialized ECU in FL!

FYI; your car will not start unless your CHT wire is connected.

As you see in my long thread, it turned out that my ECU and AFM (air flow meter) were bad. Not all repair businesses are equal, I could not get my AFM diagnosed correctly, except to measure resistance (as outlined in the manual), and to fix an air leak in the part's nose (which I did myself). My ECU had a bunch of cold solder joints (repaired), and my AFM had to be replaced with a good, used unit from Brad at 914 Limited. Only then did the car start good, run well, and idle properly.

rgare

I'll contact Specialized ECU in FL (This is the site right: http://www.ecudoctors.com/)

The CHT is only $10 on Amazon, I ordered one.

The AFM triggers the fuel pump when I open it with my finger, is there a better test procedure than checking the resistance? Could you post a link to it?

I'll try spraying the injectors into a glass and verify good spray.

Thanks again, I'll keep you posted.

Peter Zimmermann

I was not able to find any test info, except for two resistance measurements, for the AFM - that is why it was still guesswork for me. I knew that I had already done everything possible to make the car run well, and I knew that the engine had sufficient compression in all cylinders. After Specialized repaired my ECU I had nothing else left to try!

Yes, your link above is for Specialized.

Your fuel pressure numbers are weird. The spec is about 35, and I have a steady 38 - with a new pressure regulator. I use a '75/76 model fuel pump, but that shouldn't make a difference.

On the AFM, resistance should be;
Pins 6 and 9 = 200-400 ohms
Pins 7 and 8 = 120-200 ohms