Hesitance to start

BananaClip · 03-04-2009, 11:52 AM

My '88 NA has learned a new way to make me worry! When I turn the key, it turns the motor for anything like 4-10 seconds before actually starting. Once started the engine runs as well as it ever has in the 4 years I've had it.

Two main things: Yesterday I turned the key for about 8 seconds and just as i turned it back it began to start but died. I then started it again and it caught immediately. Also the temperature here started fluctuating a good 20 F on a daily basis a little before this started happening. I don't have any real correllation between temperature and whether or not it decides to start slowly, but it doesn't happen every time.

Any ideas? I don't know much about ignitions.

John_AZ · 03-04-2009, 03:45 PM

George at www.944ecology.com says it is the 2 reference sensors. At least clean the connection at the back of the engine and reset the gap per Clarks. Cover the timing mark hole with tape to avoid droping a bolt down.

How is the battery? Clean your cable ends and grounds.

On a normal start up do you think your starter drags? DIY rebuild the starter.
http://forums.vwvortex.com/zerothread?id=2359900&postid=42115781

How is the Cap and Rotor?

Go slow and do the easy stuff first.

GL
John_AZ
1988 924S 59K + 1987 924S 113K

Wallace_ · 03-04-2009, 03:53 PM

Pull off the vacuum lines for the your fuel pressure regulator and fuel pressure damper and check/smell for gasoline.

If gas is present, replace them.

What happens when they go bad is the fuel pressure slowly drops when you shut the car off. When you go to start the car again, it takes a while for fuel to get to the engine again.

This is what happened to me. Very simular symptoms as you.

alantica · 03-04-2009, 05:49 PM

Is this a DD? Temp changes effect fuel. Could be water in the fuel.

alantica · 03-04-2009, 06:00 PM

Is this a DD? Temp changes effect fuel. Could be water in the fuel.

alantica · 03-04-2009, 06:03 PM

Sorry, answered the phone. Thought I had already posted - stupid machine.

BananaClip · 03-04-2009, 10:17 PM

Well, it's been starting right away today, but once it does it runs like absolute crap. OR it runs fine and then when I get on the gas it starts running bad. The power drops way off and it idles low, at or below 800. The engine chugs, runs off- rythm and shakes the car at any rpm, and the oil pressure flutters between 2-3 bar at idle. It did this before when I was having vacuum issues, so I traced some lines around and found one near the FPR melted through, and two lines disconnected, seemingly from a white two-ended nipple underneath the intake manifold. I cut off and reattached the melted line and put the other ones on the nipple, but it didn't help.

John_AZ · 03-05-2009, 03:52 AM

Part 2:
Time to get serious-soon.
It is time to take the intake manifold off!

You have found a melted vac connector and bad hoses already. Go for it-dig in.
Materials:
Fancy Lindsay Racing Vac Kit

Intake manifold gasket set.
AOS seals
Injector "O" rings and hats
ICV rubber mounts
Expensive hose clamps
Get a new fuel filter & air filter
Label every vac line and electical connector
----------
Stuff that may be bad.
ICV hoses-usually cracked by bend near ICV
Clean out ICV
"J" boot-usually has rotten rubber nipple underneath
Clean or send out injectors

With the intake off, this is the easiest time to set the sensors and clean grounds.
Cover the timing mark hole on bell housing!
Properly prepared, a weekend job.
Your car will thank you.

GL
John_AZ

BananaClip · 03-05-2009, 09:20 AM

oh joy of joys. anyone got a vac diagram handy?

John_AZ · 03-05-2009, 11:34 AM

Quote:

Originally Posted by BananaClip

oh joy of joys. anyone got a vac diagram handy?

Does you car have one of these? From 1988 924S:

GL
John_AZ

nzporsche944s2 · 03-05-2009, 02:04 PM

Clarks has a good vac diagram under "Fuel & Vacuum Line Routing"

BananaClip · 03-05-2009, 04:08 PM

OK so today I learned that it runs better with the brake booster line removed, suggesting that I'm running rich.
And that it doesn't seem to mind having injectors 1 and 3 off at the same time. No change in RPM.

I know for sure I'm going to have to clean those injectors, but what about the vac issue? Is that normal?

BananaClip · 03-05-2009, 04:53 PM

Oh yeah one more thing. I took the AFM cover off while revving the engine, and the needle in it bounces crazily at idle. Is that normal behaviour?

Thanks for the help, all. I realize that I do need to go through the intake manifold and all the vac lines soon, but I just don't have the time or money right now.

John_AZ · 03-05-2009, 08:05 PM

How is the oxygen sensor wire? If the DSM does not get a signal from the O2 sensor it will run rich.

John_AZ

BananaClip · 03-05-2009, 08:13 PM

Oh. That's logical. I can't make out on the diagram where the wire runs to from the sensor, though. where should I look?

BananaClip · 03-08-2009, 05:05 PM

OK, it's getting worse. It definitely is a fuel problem. I can smell fuel, it runs rich, hard to start once it's been sitting. I'm going to check the fuel pressure tomorrow. The thing is, though, I've got no vacuum on any of the small hoses around the fuel rail. It doesn't respond when any of them are removed, and the check valve on the FPR line doesn't let air through either way when i blow in it. Does anyone have the part number? it doesn't seem to be in the pelican catalogue.

TSNAPCRACKLEPOP · TSNAPCRACKLEPOP's Garage

dizzy cap? cracks, wet?

BananaClip · 03-09-2009, 09:45 PM

All four cylinders are getting spark when they require it. New bosch platinum plugs. (old ones still had crap from the headgasket failure (yikes))