Odd starting problem

Thanks Guys, it kind of confirms what I am thinking.
My co-worker who is also my part-time mechanic is thinking the same. We are going to check a few readings (and I am finally going to buy myself a multi-meter this weekend and see if it gets any worse. I have a second car for a few months while I work out these kind of things.

While we are at it we are going to upgrade the battery cable to size 0 and put in a deep cycle battery and replace the spark plug wires along with checking the grounds. He also suspects the alternator belt might be loose since the alternator is a new 90 amp Bosch model, not stock, and it also has a new belt. Put on when in November. He sold me the car in Dec. I seem to be too close to 12 on the alt gauge a lot of times and I think it should be better. It might be off so when we take off the POD to add aluminum gauge rings, we will try to calibrate it.

Hopefully in the next 2-3 weeks....I need to be in shape by SITM in June!

Later

Hey Ken,
my guess is yes even though it is hard to tell without more info.

Please put your model/year of the car in your signature so that no one needs to ask in the future.

My guess is that a hose split and it is sucking air.
The reason it seems to help by pumping the accelerator is not the pumping action it is because you are advancing the throttle position sensor so that the engine gets enough fuel to start.

remove the air filter housing and with a light and a mirror look around inside/under the intake and check the hoses for cracks.

You may also have a different problem that it could be fuel or ignition.

Try to find more details and start a separate thread in the general or in your profile area.

Brad

Hi guys - looks like it is the ignition switch. Checking around I found a few posts about leaving the key all the way over then doing a little circular motion and the starter will catch. If so then it is the ignition switch. Got it to do it yesterday. Already have a starter coming, so I added an ignition switch and will do that part first. Looks like a bad ignition switch cause multiple issues or make it look like other issues.

While we are at it - here is what we will do electrically:
1 - 1/0 gauge Ultra-flex battery cable - replace original along with new connectors of course. This is more flexible because it is thin stranded copper and the sheathing is also more flexible. (from weldingsupply.com)
2 - replace cable from starter to alternator with new 4 gauge cable and connectors
3 - Replace ignition switch of course, and while we are at it, clean the connections we come across in the POD and elsewhere with Deoxit
4 - Replace fuel sending unit
5 - Replace Wal-mart battery with Deep Cycle Optima.
6 - Replace the starter if needed.
7 - Check electrical readings of course, during and after

The alternator is a 90 amp Bosch and is new last December.

then lets see how things look after that !

Great research and find. I hope the switch replacement goes ok.

FWIW, I think the easiest access way to remove/replace the ignition switch is by removing the center console and pod cover. Also, be careful not to remove the wires from the plug or you will need the schematic in order to get all the wires assigned back to their correct positions.

Replacing the starter in these cars can be tricky. You may have to loosen the sway bar to get enough clearance for removing/replacing it.

Kenbooze;4424 wrote: My 928 S4 has just decided that it wont start unless I pump the throttle like a maniac any Ideas?
Just to baffle me even more doing 30mph yesterday and lost all power it just decided to cut out are these 2 things connected.
Stumped!

In the future, please begin your own thread when your post doesn't concern the original post and/or you're seeking your own advice. Maybe you just need to familiarize yourself with the forum software more. That said, welcome aboard!

Your running issues could be sourced to any number of problems. However, the first most likely culprit is intake vacuum. The old vacuum lines are probably beginning to split causing the intake to suck in un-metered air that is tipping the delicate air/fuel balance your engine needs to perform. Start by checking the engine vacuum with a vacuum gauge. They're readily available at every local parts store. Your vacuum should be steady, at idle, when you check it. Report back your findings, in a new thread , and we'll assist from there.