Rev limiter not working

[Early_S_Man]

Lee,

Did your fuel pump stop coming on when you turn on the igniition switch? If it still comes on ... the Red Fuel Pump Relay may be bad and the reason your rev limiter isn't working! You DO have a spare one, now, right?

[Leland Pate]

Warren, you always make me feel like a dummy.
I'm always trying to figure out how I can answer things with out sounding too stupid.


Last night, I plugged that harness back in to the air flow sensor, and yes, now the fuel pump doesn't come on until the engine is cranked.

But what I don't understand is, if I had a bad fuel pump relay, the car wouldn't be running at all, right?

Oh, and the relay on the fuel pump is brand new... remember my $80 worth of relays power windows diagnostic???



I just have no idea of what to look for... there are many boxes back in the instrument cluster area. And I'm not looking forward to removing the fresh air blower unit...again... I just had it out last week when I replaced all of the cables.

Sure would help if i could find a part number... maybe I can find a box with the numbers on it...

I guess this would be a good time to use my new bore scope!


Too bad the retro rotor idea won't work.
I do have a friend in Germany, it's just that he'd be aweful pissed to find out that I was only calling him to have him mail me some car parts!



Thanks Warren,

[Early_S_Man]

Lee,

911.617.136.00 ... four wires ... Red, Brown, Brown/Red, and White/Red

The Whit/Red wire comes directly from the tach. 'TD' terminal.

Fortunately, the Red relay circuit is a 'fail-safe' circuit! Unless the contacts are burned off ... a failed relay with an open coil, for example ... doesn't keep the car from starting or running!

[pwd72s]

[i]Originally posted by Leland Pate [/i
I do have a friend in Germany, it's just that he'd be aweful pissed to find out that I was only calling him to have him mail me some car parts!



Thanks Warren, [/B]

Lee? If he's a REAL friend? He wouldn't be mad at all...he'd just ask what he could do to help... Just my opinion...but, like Warren is doing right now? Food for thought...

[Tony911Z]

Leland-

I just got back from an ICBM alert so I couldn't get back to you right away. I've looked through the Bentley Manual to find you a reference. Unfortunately, other than the current flow diagram on p. 970-9 there is no mention of it any where and with a little help you already seemed to have figured the wiring diagram out.

I removed what the diagram calls the rev limiter switch a few years back so I don't remeber the details, other than it was behind the instruments. I call it a relay module because I'm pretty sure that's what Stoddards catalog/parts reference manual called it and that's what it looked like. I just found my bad one-it measures about 2.75" X 2.75" X 1" and has a six spade connector and two spots for mounting screws. The P/N is 91161713600

I had a Rennlister send me his bad one to see if I could make one good one from the two bad-no luck because it had the same bad component on each. I also tried the local Radio Shack, but they couldn't match anything with the component markings.

[Leland Pate]

Tony, thanks for the description, this is the best info I have to go on.

Did you remove the fresh air blower assembly (in the trunk) to get at the module?

Hey, yet another Pelican USAF member...

This may require a seperate domination plot or something...

[1980SC]

Just put a euro rev limiting rotor in it. Vertex has them for about $25. I bought one for my SC from them a few months ago. It is no harder to install then any other rotor. Rated at 6800 rpms.

Another thing, I doubt your tach is accurate. When I dynoed my SC, the tach was reading 200 rpms too high. When you're screaming along at an indicated 6700 rpms, you may only be 6500. Not high enough to trigger the rev limiter. Incidently, the only other car I've dynoed was a Miata, and it's tach also read 200 rpms too high.

The rev limiting rotor works fine. It's what these 911's always used until the US '78 model got Cats, and they changed to a fuel cutout so the cat wouldn't get doused with unburnt fuel.

Rob
1980SC euro

[Tony911Z]

No Leland, I don't think I removed anything to get to the switch/module. Funny thing is that last night I pulled my intruments trying to give you a little better description and I couldn't find the six pin connector that it used to connect to.

If you still can't find yours let me know--I can go back in because this time I have the old module and can look for the appropriate size mount.

USAF "lifer" (19 years, 3 months Time in Service)