Another no start issue no spark or fuel

[Len 911]

Update..replaced the sensors a it fired right up...took it for a spin and it ran great...thank you everyone for your support..

Len

[steely]

You are the man.
Congrats!!

[pmax]

Originally Posted by Len 911

Update..replaced the sensors a it fired right up...took it for a spin and it ran great...thank you everyone for your support..

Len

[Pakalika]

I have the same issue. Drove the car (1984 911) to work. In the evening would not fire. Battery is good. I did not smell fuel in engine compartment. On this forum, saw the below. Before I attempt: does anyone know do I turn key on? And how safe is it to short the bottom of terminals 6 and 5 as indicated below:

3. You can jumper a hot wire to the fuel pump and listen to it whir to prove that it's working. Run a short wire from the fuel pump fuse (#6) to an adjascent fuse (#5 or 7) at the bottom of the fuse terminal, the pump should whir. BTW my car didn't have the fuse info on the fuse cover (I think the old one broke), so Jim Bauman gave me his info from his '86 (#21 is closest to the front of the car):

[proporsche]

Hi..you fuel pump fuse is no 6 from the windshield.To test the fuel pump you do not have to have the key on...also do not run the pump too long.
If it is not running with this simple test.Either lift the front of the car and hit the protective metal in the middle The pump is right above it.Of course then you can check if you are getting any juice to it too....if it is not running....for that you have to remove the metal plate cover number 8mm Allen and 17 mm socket will do the trick.

Ivan

[Pakalika]

Thanks Proporsche. Will try it.

[Pakalika]

Hello Proporsche Ivan. Before I shorted I put a meter across and measured 12V. I shorted and heard a buzzing sound. My guess it was the pump. Only held it less than 5s. Went to the engine compartment and still did not smell any fuel. However tried starting with no luck. SHould I have held the short longer? Appreciate in advonce for answer

[proporsche]

Hi..do you have an extra DME relay..That is the start..looks like the pump is fine...do you have any alarm in the car or kill switch?
Ivan

[Pakalika]

Hi Ivan,

Nope don't have a spare DME relay. That was the other thought. No alarm or kill switch. What is strange, I drove it to work in the morning on the day it happenned. In the evening it turned but not fire. I thought it was the cold weather 0C. The fuel tank is full. Well thanks for your efforts will have it towed to the shop

Mahalos
pkp

[proporsche]

before you tow it take the relay out from under your seat with 10mm socket ..
and look at this video if you can repair yours

Ivan
https://www.youtube.com/watch?v=cfrErbd1RQ8

[Pakalika]

Hello Ivan,

removed the relay. In fact looks fairly new. It can't be opened like the video. I did look at the video. I did prior to your note doing research as well. I took an ohm meter and checked out the contacts and all looked okay. However don't hear it pickup when I turn on the key. Anyway I am in my office parking lot and need to get car out before work week. So can't mess with it anymore. Again appreciate all your help

Mahalo Plenty
PKP

[proporsche]

ok sorry ..yup take it home.....
naʻu ka hauʻoli

Ivan

[Pakalika]

Mr. Ivan (Proporsche),

You'd never guess. As mentioned took out the relay inspected it. Installed back, tried starting twice no luck. Called tow truck, waited and waited. 3 hours later went back out to wait for tow truck. Gave one more shot. Yes it started! Tow truck showed up couple minutes later. Since Wed I tried starting 2 each day no luck. Have not changed anything. ONly difference is the outside temp whcih is 2C degrees warmer today than the other days.

Or must be the akuas (gods) are with me today.

What are your thoughts?

pkp

[proporsche]

hi ..inspect your no 6 fuse connection...check all your connection back in the engine compartment,those 3 plugs on left side of the engine....
here


later if you can you to check these values...

[Pakalika]

Hello Ivan,

#6 connections look allright. Will try to get the measurements on the plug. It started right up up this morning. Well 911 is in a controlled enviroment .

Mahalo
pkp

[proporsche]

Hi..in this case it is very possible that your temperature sensor is giving you problem.
That is top white plug.Disconnect it and look at the female connector.Does it have one or two prongs.If one it is the old version and very old by now.....then we go next

Ivan

hereis some reading

https://www.porscherepair.us/porsche-911-1984-1989/cylinder-head-temperature-sensor-testing.html

[Pakalika]

Hello Ivan,

The temp sensor had no resistance at all and the reference sensor was intermittent. This made a some sense it did not fire when cold. Apparently couple of degress made a difference. Will have it changed out. Again thanks for all the help. This is good info.

Mahalos
pkp

[proporsche]

u r welcome;-)

Ivan