I need to know if I have a `73 or a`74 2.0 engine.Both serial # have the GA95. I`m having trouble with the temp sensor,and it`s my understanding there is differant one for the `73 than the `74?

Which temp sensor are you having trouble with? There's generally a number ON the sensor that should identify it.

GA0000001 thru GA0006765 are 1973 2 Liter engines.
GA0006766 thru GA0015021 are 1974 2 Liter engines.

Thanks smg914 that`s what I was needing.

What matters is the FI setup. The engines are the same. The Cap'n

QUOTE (Cap'n Krusty @ Aug 8 2005, 03:17 PM)

What matters is the FI setup. The engines are the same. The Cap'n

but it's nice to know which engine you have because the 1973 center console temperature gauge was different than the 1974 center console gauge along with the fact that there were 3 different part number oil temperature sensors used. But I think 2 of them gave the same temperature results.

so the engine # is GA014241 . didn`t see anymore numbers. Ok now I think the engine had the stock F.I. system when I pulled it out of the parts car. How do I tell if it`s a stock to that year? My reasons are ... (1)For the temp sensor I have been running just a fader switch in place of it (something I read here I think?). (2) I bought a new temp sensor for a `73 (part #311906041A)@ $40.00 there is differant one for the 74 engine @ half that price (3) When I plug it in the engine won`t start.(4) Maybe the sensor is bad. I just want to make sure it`s the right part before I do anymore.

Again, WHICH temp sensor are you talking about? The '73/'74s had THREE, one for air, one for cylinder head, (both for the FI system), one for the oil temp gauge only.

QUOTE (72914S @ Aug 8 2005, 03:28 PM)

ENGINE NUMBERS?, How do I tell the year?

by looking it up in the "914 Info" section. there's a link to it on top of every page on this BBS ...

Andy

sorry 1 it`s the head temp.

According to Brad Anders (and he would know better than most), the two CHT senders are part numbers 0 280 130 017 and 0 280 130 012. The former is for use with the 1.7 ECU, which is the same for the '73 2.0. The only difference is an additional resistor, part number 039 971 762 A (just a 270 ohm resistor, any Radio Shack 1/4 watt unit should do) for the early part has to be between the sensor wire and the ECU. The 012 part is for the '74. Note that those are Bosch part numbers. The Porsche part number is the SAME for both: 311 906 041 A, and Anders suggests either will work fine, the 012 will just give a richer mixture during cold starts.

What kind of sensor problems do you seem to be having? If the sensor and the wiring is at all good, then the car should start and run OK cold, and by the time the engine is warmed up, there will be no difference at all.

When I hook up the head temp sensor the engine will not fire, but it will run when I have the rayostat(sp)hooked up.well I guess I `ll head on down to radio shack and try that resistor I`ll let you know how it works.I do need to check and make sure the sensor is good. In case you haven`t guessed I`m not a technition just a(good) parts replacer.

Measure the resistance of the head temp sensor AT THE ECU. Brad Anders' site has all the troubleshooting info anyone would ever need.

Anders' D-Jet site

It's likely the sensor is bad, or there's a wiring problem that causes it to be "open" (infinite resistance, like a broken wire or bad connector) at the ECU, which typically causes a no-start problem. Even new sensors can be bad, so just replacing it isn't necessarily a good fix. Test the sensor against the values on Brad's site.

It sounds to me like your CHT sensor is grounded. If it is grounded, it's telling the control unit that the engine is red hot even if the engine is ice cold. On the other hand if the sensor lead is broken, open or not connected the control unit thinks the engine is ice cold even if it's warm or hot. Make sure the CHT is screwed in properly and connected to the cable going to the control unit properly. Also make sure your cold start injector is working.