Start your engine!

[Anfinn]

Well, today was a big day in my restoration! I had the engine running for the first time in 18 months..

It ran beautifully, no black smoke from the exhaust, only white steam.

Idled a bit fast at 1200rpm, which might be because I have removed the AC, and it doesn't have to turn that big compressor any more.

I still have a few issues though:
The generator indicator light didn't extinguish until it reached abt. 1500 rpm. It then stayed out till it came back to idle again.
Is that a sign the voltage regulator needs renewing? Fan belt on the generator didn't seem to be slipping.

I also had to start it via a jump lead to the G-teminal on the TTS. There is no sign of activity from the starter when I turn the key to the start position.
I have renewed the barrel in the ign. lock, but I am not aware I have changed anything at the connections.
I have put off starting to take out the instruments again to get to the back of the ignition sw., but I guess that is the next step.
Can't see how the wires can be wrong as the connection from the G-terminal goes via the 50-terminal on the ign.sw., and that works.

Anyway, a good day overall.
Now I don't have to loose any sleep thinking the engine will be a big project to get going.
I had only had the car running for a short while before. When I purchased it, the brake booster was shot, and the exhaust had big holes in it.
The new SS exhaust sounds very nice.

I must thank everyone who contributes to this site. The information here has been invaluable help to me.

[ja17]

Hello Anfinn,

Most likely one of the relays for your starting aid is not activating. If you open the relay you can clean its contacts.  Look through the tech manual  for some other diagnostic procedures.

Check the cable going between the auto transmission and the nuetral safety switch to make sure it is moving the lever arm on the switch. If the cable is kinked or broken the starter may not activate.   You can manually move the lever to  get it into the right position so that  the engine can be started. (caution! it may also start in any forward or reverse gear!).  The ignition switch does have an electrical switching unit attaced to the back of the lock assembly. Three small screws hold it in place.

A voltage regulator or alternator can give the symptoms you describe.  Put an voltmeter onto the battery while the engine is running The system should put out 13.5 to 14.5 avolts .

What year and model is your car?

[Allenh]

Congrats on a successful test launch!  Use a volt meter to see if voltage is applied to the TSS in the start position.  Bet you don't have it, that is why you jumped it.  I had the same issue and I did not want to believe the ignition switch was bad, it was.  You will need to pull the dash apart there isn't need to check if there is voltage to the ignition switch, cause ignition, fuel etc work.  same feed.  Have fun.  I got mine in one day from an online parts house.

At least you are near completeion, I just developed a cylinder head issue and I am in process of disassembly- I would trade a dash job for a cylinder head anyday!

Allen

[Anfinn]

Thanks for your encouragements and advice.

ja17, The car is a -71 model 280 auto (produced October -70)
I don't think there is anything wrong with the starting lock and reverse light-switch, as the current goes through this one from the G-contact also  (after the 50-terminal on the ign.sw,.)
I have contact both in N and P, and the reverse light works.

Will a fault in a starting aid  relay stop the starter engaging?

Anfinn

[Anfinn]

The ignition switch has been replaced, and it now starts using the key.

I have still got an issue with the idle, though.

First, I have found that the FI pump must have been changed at one point. I have a model R20, which is not correct for a 1970 280SL according to the BBB. I don't know if this has a bearing on my problem..

I suspect it is running very rich, as when I started it from cold, and with the air filter on the FIP off, it was idling at 2000 RPM.
When I put my finger over the air filter inlet, the speed reduced to below 1000.

Trying to adjust the idle screw on the FIP, I have turned the adjuster CCW. Now it does not "spring free" when I let go of it. It seems to stay engaged in the slot.
Is this a problem? Is there a positive stop which prevents you turning the screw too far? I am a bit worried about starting the car with this situation, in case I ruin something...

[wwheeler]

I have a question regarding the ignition switch issue. I have developed a situation where I try to start the engine hot just after it was shut off (for IP mixture adjustment). There is no starter noise at all. If I retry to start, the starter will catch. However, the problem is slowly getting worse so that it now takes several retries for the starter to catch. Strange thing is that when I begin to release the ignition switch from the starting position, I hear a brief mechanical noise from the starter/solenoid.

The starter/solenoid and the TTS are a year old, battery at 12.8 volts (engine not running). Positive battery cable is also new. All connections look good. I have not been able to test the TTS G terminal voltage when it acts up. Would the ignition switch fail only when the engine is hot? Sounds like I am missing something but not sure what.

Thanks for the help.

[Anfinn]

Restart by using a jump lead to the G-terminal on the TTS.
If the problem is absent when using this route, I would seriously suspect the ignition switch.

[wwheeler]

Thanks Anfinn,

Just to be sure, I connect a jumper wire from the positive pole of the battery to the G terminal of the TTS. Does the ignition switch need to be in any certain position? I am assuming the engine won't start, rather just turn over because neither the ignition nor fuel pump has power. If this sounds correct, I will give it a shot this week.

[Anfinn]

Yes, that is the correct connection.

The key should be in position 2, - the position before you turn it against the spring loading to engage the starter.
The fuel pump should be running in this position, and the engine will start.