928 wonts start-clicking noise from intake manaifold

parobu · 08-21-2011, 03:34 PM

Hello, I hope someone can help with this. I have an 88 928 with 95K miles. I bought it in April this year and have not had a bit of trouble until now. I parked it in the garage one day and the next it was hard to start. Tried the starter and it turned over a few times, finally it started and ran for about 45 seconds then turned off. Now it will try to start but not quite catch. Also there is a rapid clicking noise when I turn the ignition on. It sounds like it is coming from the intake manifold area. I would appreciate any advise.

bluemane500 · bluemane500's Garage

is the clicking noise when the engine is turning?

bluemane500 · bluemane500's Garage

my car once had a cam gear fail, so the car lost its timing order turning over the engine was a loud clicking noise and it would not start, the noise was the valves hitting the pistons,, i hope this is not the same problem,,engine replacement for me,,,, good luck,,,, when was the last service to your timing belt?

parobu · 08-22-2011, 05:32 AM

Thanks for the input! The clicking noise is when the ignition is in the on position.
I was playing with the relays and when i wiggled the Fuel Injection relay the clicking would begin with the ignition off. I am going to get a new FI relay today and see what happens.

parobu · 08-22-2011, 02:12 PM

Well new Relay did not fix no start problem. Not sure what to do next.

parobu · 08-22-2011, 02:13 PM

Oh the timing belt was done 10K miles ago.

76FJ55 · 08-22-2011, 02:20 PM

There are lots of threads on no starts if you do a search, this will probably get you the most suggestions in the shortest time. Just the time it takes you to read vs waiting for replies. But you are probably starting in the right area with the relays. Instead of replacing the relays have you tried jumping them. That way you can rule out the relays them selves.

hss1960 · 08-22-2011, 03:10 PM

Sounds like your LH brain is fried.

Mrmerlin · 08-22-2011, 04:09 PM

your LH computer needs to be rebuilt,
this is a classic symptom,
the injectors clicking with the key in the run position.

While you send off the computer also send out the MAF and have that rebuilt as well, this will restore lost performance, and provide a reliable car

parobu · 08-22-2011, 06:57 PM

Yes, After much research, It looks like it is the LH ECU. As this is my first 928(had 924 years ago)I had no clue that jump starting the car could fry the ECU! I left the blinker on after driving a week ago and that draned the Battery. I jump started with no problem, but then would not crank the next time. It looks like the company in Florida has the best price for a rebuild at $400 incuding shipping. How dificult is the ECU to remove?

Mrmerlin · 08-22-2011, 07:13 PM

disconnect the battery ,
then remove the passenger side foot well carpet and the clip that holds the side cover.
Remove the parcel tray for ease of removal.
Push the clips on the harness connectors and pull the connectors off the computers,
then remove the allen bolts that hold the mounting plate to the body there are 2,
once this is done remove the vacuum line and any other connectors that are on the computer board, then pull it straight to the rear of the car.

parobu · 08-22-2011, 07:17 PM

Thanks Mrmerlin! Also thanks for the tip on the MAF. I have seen some threads that some owners have seen a big improvement after rebuilding.

LUFTMAN · 08-22-2011, 10:04 PM

next time you have to jump start a dead battery on these cars in a emergency turn on headlamps first it may save the lh control unit by taking the surge of power away from it on a jump start. but the best way is the long way charge battery at a low rate because a battery is cheaper than a control unit.

Danglerb · 08-23-2011, 02:27 PM

Don't jump start. Open the rear hatch, disconnect the ground strap where it attaches to the frame with a wingnut behind the toolset, hook the negative side of battery charger to the disconnected ground strap, positive to the jump post, charge the battery. Remove the charger, start car. I use a 20 amp charger and it takes about 20 minutes to put enough of a charge on the battery to start the car.

Not much spread in cost between cheapest and best LH rebuilder, I would use the best, Porsche Electronics Specialist - JDSPorsche or Rich Andrade (don't know his details). Roger at Home - 928's R Us Online Parts Catalog can do an exchange for the jds units.