Intermittent no start-flooding

dgdubya · dgdubya's Garage

'85 930 with an annoying flooding habit.

So about 50% of the time, my 930 will flood and not start. Perfect example. Got it ready for the season last weekend. After sitting all winter, hit the key, started right up, washed, oil change, check tire pressure, etc. go for first drive of the season. Yesterday, get in, turn the key and floods. Same thing today. Did the same thing last summer but was too busy to do anything about it.

Fuel pumps do run as soon as the key is turned and even though that's not right, was never a problem. Thermotine switch? I'm going nuts with this. When it runs, it runs like a champ. The problem is when it runs...

Thank you in advance.

Luckyboy · 05-26-2018, 04:49 AM

Check the cis air flow plate, it sticks some times.

dgdubya · dgdubya's Garage

Will do, thank you.

mark houghton · 05-29-2018, 05:15 AM

Intermittent ignition problem, loss of spark perhaps. Have you checked
spark when this happens?

puddy · puddy's Garage

My car does something similar. 1 out of 4 attempts to start, it cranks and cranks and I have to hold my foot at part throttle and after what seems like an eternity, maybe 30 seconds, its fires.
most of the time I just flick the key and vroom.

So if it is in fact a sticky air flow plate, how does one correct that?

turbo ride · 05-29-2018, 09:21 AM

Maybe you have a bad injector or injectors? Last spring my car ('91 964 Turbo) developed a cold start issue - if it didn't catch on the first starting attempt - it would "flood". I'd have to remove the fuel pump relay, crank - it would then fire up and run on the gas already in the cylinders for a few seconds then die. Key was to get the relay plugged back in before it died. After that it would run fine all day. Fast forward - I had my motor rebuilt this winter and had the injectors (including CSV) sent out - tested/cleaned. Turns out one of them was dripping and spraying too much. That one was replaced and the others were cleaned and now they all spray the same. Starting issue gone. Just a thought.

T77911S · 05-29-2018, 11:10 AM

could be bad injector. one injector should not keep it from starting though.
if you have several that leak it could flood it after you shut it down.

could be plunger is sticking

if plunger is sticking and the FP's run with the key on, that does not help the situation.

the TTs is a thought but the CSV only gets power when cranking.

mark houghton · 05-29-2018, 07:29 PM

Rule out one thing at a time. Make sure your ignition is working when this issue raises its ugly head. If all is good in that arena, then put it behind you and look toward fueling as already discussed. Saves you from chasing your tail.
Lots of good advice here. Why do you think it's flooding, vs. just starving for gas? Are you smelling gas fumes, are your plugs wet which would indicate flooding? Or the bastard just won't start and you're assuming it's flooded?

peterpullin · 05-30-2018, 03:27 AM

had a similar issue with my 91 turbo. one of the o-rings that seal the metering slits to the outer case was gone. so fuel was able to find it's way to one or more injectors. depending on crank position it was a problem or not.
i was not able to find this with cis guges. was all in spec. no huge amount of fuel but enough for some problems.