khalloudy

Ok so i get back to Lebanon and finally get to drive my car. The dealership scratched the front bumper, engine bay looks like crap, broke a plastic piece of my tire inflator, broke the spare tire cover, installed the battery without the +ve post cover, and did not secure the batter. LOVELY. Bill? $2,633. LOVEEEELY.

I take the car our and it is running well and i take it for a spin upto 260km/h all is well.

Today i take it for a drive and suddenly the car idle fluctuates then dies. Weird. I crank it and it starts right up no problem. it does it again 10 minutes later. Same symptoms then runs fine!!! get to dealership all is well. They fix my battery connection and all and i go back home.

I clean the car then head to the barber. All hell breaks loose. The car starts to stall, idle fluctuates and idles at 600rpm or so and car dies. weird. I press the accelerator and the engine makes weird noises, but runs and it feels like it is not all firing or something fishy is happening. Limped the car back home and parked it. I checked the power at the engine post:


13.43V at idle with zero load
12.4V at idle with A/C, Headlights, Fog Lights

Any idea why is my car running like crap. I mean i press the accelerator and the engine is about to stall!! oh and the power... does this show an alternator issue?

Thanks

dprantl

Sounds like an electrical issue. How old are the LH/EZK/Fuel pump relays? What does the front jump post look like? How about the rear ground strap? And the big connections on the top of the fuse panel?

Dan
'91 928GT S/C 475hp/460lb.ft

khalloudy

relay are all new. i have replaced all the relays like a year ago with the new plastic ones from Porsche (VW). Front jump post and rear ground strap look good as well as the top of the fuse panel... nothing out of the ordinary.

Talked with Rich today and he too thinks it is purely an electrical issue. His recommendation was to start with the alternator as it should hold high 13s even with load at idle (should not change). Mine is showing 13.4 with no load at idle dropping to the 12s with the load at idle.

khalloudy

This car is just tooo funny. Took it out for a spin tonight, everything is running normal. All the power is there, idle at 675, with AT engaged at 625 no hesitation no stumbling no nothing... ran like clockwork. This car is gremlin city

Shark Attack

1. Chk the battery terminals, Especially on the POS side where the computer wires attach with a little nut
2. Clean the contact where the ground strap attached to the body.

I think that is as good a starting place as any.

khalloudy

funny you mention the ground strap. I had the maid clean the nut and tie bolt with copper cleaner as they were showing rust and oxidation... and seems to have improved a lot of things!!! i will check the rest as you suggested

Rob Edwards

Crap, I gotta get me a maid!

khalloudy

I am thinking of giving her the list of the spring cleaning items as listed on Pirtle's page and let her spend tomorrow cleaning all the car's ground points. I guess then she can say she is really earning her wage :-D

khalloudy

Update:

got the alternator replaced today with a new one. Here is the dilemma:

at idle with no load 13.8V
at idle with A/C cold, Fan at 4, Lights and Radio 12.8V

What is the story? i thought it should be at 13.8 at all times at idle or am i wrong? i will be performing the contact cleaning and adding DeOxit to all ground points tomorrow. Any help is appreciated

Rich9928p

Running good then bad indicates a corroded connection somewhere. As much as this poor 928 has been shuttled from AZ to the middle-east with many not so knowing hands on it; who knows what could be corroded?

Where are you measuring the voltage? The best place (and least convenient) would be to measure it AT the alternator, that way you don't see voltage drops.

If you are at 12.8V with such a heavy load AT IDLE, I'd say you're OK. This shows the alternator is keeping up with the load. Does the voltage increase a bit as the RPM increases?

khalloudy

Rich,

woohoo just got home from another crazy night (yes the 928 was with me). The voltage does increase with RPM (at least that is what the needle inside the car shows. I think i should clean all the ground points and the +ve point in the engine bay... well as soon as i sober up tomorrow at least :-D

P.S. i have been measuring the voltage between the engine jump point (+ve) and the engine cross brace (ground)