Dan87951

The 928 has become harder and harder to start lately. It will crank and crank but after the 4th or 5th crank it finally starts (This is with a COLD ENGINE). I'm thinking the fuel pump could be dying on me? This only happens when the car has been sitting for over an hour or so. If the car is warm the car starts right up.

the flyin' scotsman

Is it an auto?

After an hour would indicate the engine is warm........correct?

IcemanG17

Sounds like the fuel pressure check valve

FeedNfrenZ

Fuel pumps, fuel filter, check valve (It's in either the filter or pump? help me out guys), leaking injector. A fuel pressure gauge at the rails would help!

jyoon

crank sensor?

Dan87951

Yes its an auto, when the engine is warm its easier to start.

the flyin' scotsman

Your first post stated that it was hard to start after sitting for an hour. After only that amount of time the engine is still very warm/hot in fact its heat soaked; hotter than what it would be if it was running.

A fuel pressure guage would indicate what pressure you have while running and for how long it maintains that pressure after shutdown.

Given that its an auto when was the last time you released the flex plate?

Dan87951

Sorry guys I made a bad mistake. The car is hard to start when the ENGINE IS COLD. After I finally get the car started and shut it down and go out and restart it within that hour window it will fire back up. Sorry to much to drink tonight...

the flyin' scotsman

Ok...........no worries.

If all regular maintenance is up to par (plugs, caps, rotors, wires, filters including fuel, fully charged battery etc.) then I'd headed down the fuel path.

Dan87951

Just did all that stuff but the fuel service. Haven't done the fuel filter yet. Just finished the t-belt and basic tuneup about 2 weeks ago. I think I will deal with it for a while than change the fuel filter out and see where that gets me.

Tom928

Not trying to hijack the thread; however, I am currently experiencing this same issue on my 81 - becoming increasingly hard to start when COLD (5-6 cranks). After its is warmed up it starts in 1 or 2 cranks. I have replaced the fuel pump (with check valve) and filter and I no longer have the buzzing noise; however, it made no difference in how long it takes to start the engine.

Could this be a cold start valve going bad?

Cheers

Dan87951

This is weird went out this morning after the car had been sitting all night and she fired right up on the first crank...

the flyin' scotsman

while it's weird the problem is still there..............change the fuel filter and check the pressure engine running and when shutdown.

Is the MAF original?

leperboy

From Nichols' site, here is a test for the check valve written by Dave Roberts:

Let your 928 sit overnight or at least 8 hours or so.
Instead of trying to start the car as you normally would, turn the key so you engage the starter for just a second and turn the key back off (do not let the car even try to start), do this 3 or 4 times in a row. Then try to start it like you normally would, if it starts OK at this point then it is most likely the fuel pump check valve.

Basically what you are doing with this procedure is "cycling" the fuel pump (the pump runs for a few seconds every time you engage the starter) to build up fuel pressure in the system.

Note: If you listen carefully every time you do the starter engagement as described above you should hear the fuel pump run for a second.

Due to the changes in the climate you may want to take a look at the connectors on you temp sensor II and also test it for proper operation.

Bill Ball

Or you could just jump the FP relay.