Starting problem

Stanton Horne · 03-04-2004, 12:32 PM

My friends 928 is hard to start. The starter has to really spin before engine will start. Anybody know where we can look for the problem this weekend? Thanks

Iggy · 03-04-2004, 02:10 PM

There are a number of things to look for, but the most obvious include checking to see whether you have adequate fuel pressure. Is it always hard to start, or just when it's cold? Does it run fine once it's started?

What year 928 is it?

Stanton Horne · 03-04-2004, 02:15 PM

Its an 86 and yes it runs very good once it is started. I have not checked anything yet. Thanks

..P · 03-04-2004, 06:28 PM

Check the temp II sensor, the thermo time switch (both right up front on top front center of the motor, and the fuel injection relay. The relay can be dying a slow death and cause "symptoms". The two sensors I mentioned communicate to the cold start valve and/or the computer brain. As noted, fuel pressue can also be a problem, and it is solved by an inexpensive check valve replacement.

good luck

P

Stanton Horne · 03-05-2004, 04:42 AM

Thank y'all. We now have a starting point that we didn't have before.

Iggy · 03-05-2004, 07:31 AM

Adding to the temp sensor issue, once the car is warm, can you shut it off and restart it easily?

Stanton Horne · 03-08-2004, 04:25 AM

Here is the story. Seems to be getting worst. My friend tried several hours with no luck to get it running. We checked the fuel volume - about 1 pint for a 5 second starter turn. We discovered green like corrosion on the wires on the 2 sensors mentioned earlier. Cleaned them - finally got it started but seemed to be bad flooded after it started. We drove it 80 mph and around town. Turned it off -Would not start. Attached an additional battery and a charger - and it starts every time(slowly). Will not hit even with 2 batteries, but add the charger and it starts every time after it spins for about 2 seconds. What do you think? The two sensors in the front?

Iggy · 03-08-2004, 08:49 AM

This is getting beyond my experience, but I'd guess that you have an issue with getting enough juice from the battery to the car. The current battery may be too weak to overcome the problem, and the new battery just barely strong enough with the charger. Where are you attaching the charger?

You're going to have to start running through a list of possible fixes and anticipate that you may have a combination of issues instead of just one.

Here's a good starting point for trouble-shooting:

928 Tips

..P · 03-09-2004, 06:06 AM

If the one battery will spin the car over adequately and it won't fire, then I'm back to the two sensors. On my '83 I had to crank and crank to get it started. I tried a squirt of starter fluid and it fired immediately.

I replaced the Temp II sensor and it didn't fix the problem. I eventually took it in to the shop and they replaced the Thermo Time Switch, which fixed it. Had I known about the TTS, I would have replaced it, but I thought it was the water temp sensor and overlooked it. It controlls the cold start valve, or cold start computer program of sorts.

In any case, these sensors will cost about $80 for both of them, and if you install them and it doesn't fix the problem, at least you've narrowed it down and have a couple new sensors.

regards and good luck, P