Vipermn1961

Had been running excellent, just shut off and i drifted to the side of the road. Just had fuel pump, new relays, etc installed few months back. Any easy way to see if its getting fuel, and to test for spark?

Vipermn1961

Forgot to mention that it's a 1986 928S, automatic and that it cranks fine just won't start.

Leon Speed

Hi and welcome.

First check if you can see the timing belt when you remove the air intake hoses and peer down the timing belt covers. If the belt is there, bridge the fuel pump relay or swap it for another "53B" relay, such as the one for the HVAC blower or the horns (positions X and XII) on the relay panel for your model.

PorKen

Does the tach needle move when cranking?

Has the Crank Position Sensor been replaced?
(It's 3 terminal connector under the airbox is often falling apart.)

rexpontius

And dont forget to check the ignition switch, my car also 'died' randomly because of worn ignition switch

Vipermn1961

Timing belt is there, tach needle moves slightly while cranking. Switch fuel pump relay with horn relay and still no fire. No fuel smell (like flooding) while cranking.

Vipermn1961

how can i test the ignition switch?

Leon Speed

Can you bridge fuel pump relay terminals 30 and 87 and check if you hear the fuel pump running?

Vipermn1961

Ignition shows 12.5 at coils. Bridged 30 & 87 at fuel pump relay socket and nothing. So fuel pump?

Vipermn1961

I can hear the fuel pump click but it doesn't run?

Leon Speed

I would check voltage at the relay socket and at the fuel pump. If there is voltage, reversing polarity on the fuel pump might free it up, but be careful with fuel and electricity.

James Bailey

Run a jumper wire from the battery+ to the fuel pump+ the cover under the tank has two 10 mm nuts as I recall it hinges down and you can see the pump. One failure mode for the LH brain is it stops energizing the fuel pump circuit.

namasgt

Fuel pump fuse? (Its a 10 amp I believe) By hearing the clicking do you mean from the fuse panel or from the back, the pump should make a hummmming sound when it turns on not clicking. If you hear the clicking from the fuse panel then its a relay making the sound. Check the fuel pump fuse its one of the last ones on the very right of the fuse panel.

namasgt

Also, for the near future, please make sure you check your flex plate and crank shaft end play to prevent detrimental engine damage. Common for all 32 valve automatic 928s. Search for "flex plate" release or Trust bearing failure (TBF) on this forum.

James Bailey

15 amp fuse slote 42 on the board