2.0 Djet Engine Floods when HOT

Reason4Living · 08-28-2006, 06:52 PM

Help! My car starts when cold and idles well. All hoses have been replaced and there are no brittle or broken electrical wires. Here's the problem, I will drive to the store and when I get back, the engine starts and shuts down. In order to get it started again, I have to hold the gas pedal down while cranking the engine for like a minute or two. Sometimes it won't start at all and I have to leave it to sit until the car cools down. This only happens when the engine is hot from driving, not hot from idling. It has a new fuel pump, injectors and the pressure is right at 30r.p.m. No leaking vacuum hoses either. Any ideas?

bd1308 · 08-28-2006, 07:02 PM

OK. Some homework for you

A) Do a goodle search on Brad Anders. I forgot his site address, but he is the D-Jet man!

B) Test and Verify these items:
CHT (black wire coming from tin by #3 plug)
Looking for around 2.2K Ohm when cold, and around 100 Ohm when hot. Real High when cold, Real Low when hot, if Zero it will be super lean, and if Infinity it will be super rich.

CSV Is it leaking? For 2.0 models the CSV connection goes from the plenum to the driver or passenger fuel rail.

look for corroded and or broken connections too.

b

Brian Mifsud · 08-28-2006, 07:30 PM

Brad Anders:

http://members.rennlist.com/pbanders/

bd1308 · 08-28-2006, 07:40 PM

Thanks for the link, I was goign to add that but got sidetracked.

b

Reason4Living · 08:22 PM

After checking out Brad Anders site, it looks like the problem may be the cold start valve. It may be stuck open which is why it has no effect on starting when cold, and when hot, the excess fuel floods the system. What I don't get is how come when it is hot, I can get it to keep running by depressing the gas pedal and giving it gas until it revs into idle. This leads me to think that the gas is getting "sucked out" of the fuel lines when I turn the car off. This is all very confusing but I will check it tomorrow and see what comes.

bd1308 · 08-28-2006, 08:30 PM

Oh

another thing, since you have a 74.

Sometimes the fuel pump gets hot, and the liquid fuel evaporates in the lines to form a nice air pocket, and those pockets cause the pump to cavitate for a while, resulting in a no-start situation.

Hence the reason for Porsche/VW to move it upfront.

b

Reason4Living · 08-28-2006, 08:49 PM

The fuel pump is in the front, under the gas tank. The idea of fuel evaporating in the lines is interesting. I don't have a problem getting the car started, starts right up and idles strong. It is after driving the car when the problems starts. It's as if the fuel is getting sucked back because when I start it, it starts only to die unless I press the gas pedal in time. If I don't press the gas pedal in time, I have to hold the pedal down to the metal and crank it over for ever! Sometimes this doesn't do the trick. You can imagine the frustration when trying to leave someplace and this happens. The worse is having some old guy tell me what a piece of ***** these cars are while trying to get it started. I need to fix this problem A.S.A.P.

bd1308 · 08-28-2006, 08:54 PM

Man! You bring back some of the lesser enjoyable moments of 914 ownership.

Imagine being a college student and having a dying 914 on the road, driving 120+ miles every other weekend.

And being stopped at lights, and having the car die and unable to start again.

Very embarassing.

I never did find out what the problem was, but I bet that it was the components not being matched. Somehow I doubt a 1600 type3 MPS would work in my 2.0L 914.

b

Reason4Living · 09:09 PM

Yes, it is very embarrassing. I've had it die at an intersection on my way to work while waiting for the light to turn green. Good thing the car is so light, I was able to push it out of the way.

I am going to check the auxiliary air regulator tomorrow. Somehow I doubt the cold start valve since the car runs great when cold. I will post my findings and put an end to the mystery.

bd1308 · 08-28-2006, 09:13 PM

Toward the end, I had to heel-toe it every DAY. That was annoying.

And then I dropped a valve seat, next engine.

I would start checking part numbers too. And honestly take a look at your timing and dwell and trigger points, etc.

All of those will make your car run like absolute crap when hot.

For example, I set the timing way retarded....ran good due to AAR when cold, ran REALLY low rpm and sluggish and died all the time when hot. Check it out.

Also Trigger points can get worn and makeup extra pulses, which make the mix really rich.

Also check the hose leading to the MPS and check the MPS itself.

b

jjr · 08-29-2006, 01:54 AM

Greetings; I had a shutting down problem when hot problem with my stock 914 1.7L Djet, I replaced the relays on the relayboard, cured! Always try the simplest solution first, it took me a while to get there... GL

bd1308 · 08-29-2006, 02:56 AM

Awesome point.

Rusty contacts on relay caused the fuel pump problem I later experienced.

b

hardflex · 08-29-2006, 03:58 AM

there is fuel pressure in the system even when you shut it off, if your cold start valve is leaking, that pressure would force the fuel into the intake manifold where it would accumulate. It would start more readily when cold, because it wants a rich mixture, and probably is "settled out some, or evaporated out, none of which would happen when you you restart warm.

When my car was flooding (from a leaking cold start valve) i used to unplug the electric plug from the MPS and start the car with the pedal down. This would dry out the system quicker and it would run for a short time on the fuel in the system until it was gone. Then, plug it back in and it should start and run normally, although still rich from the leaking CSV

I have disconnected my CSV from the system, but i'm in a warm climate where it will never be used. It only works at 32 and below.

Reason4Living · 08-30-2006, 04:04 PM

I am just learning, what exactly is the MPS?
Please, don't laugh, but can anyone tell me where I can find the spark plugs? I have no idea where these are and the Hanes manual does not specify their location.

Bleyseng · Bleyseng's Garage

MPS- Manifold Pressure Sensor
spark plugs are in the engine- follow the 4 spark plug wires to them.

Reason4Living · 09-03-2006, 04:38 PM

As it turns out, it was the Cold Start Valve that was making the car run bad. I unplugged the hose that goes to the air filter and now it idles and runs good.

I remember when I first got the car, I would freak out and begin messing with everything. The last time I did that, I bought a new fuel pump thinking the old one was wasted. Found out later that the problem was a corroded negative battery ground that just needed to be cleaned with baking soda and water.

Thank you all for your expert advice. Without you the car would be resting in peace in the garage.

Dave at Pelican Parts · Dave at Pelican Parts's Garage

The CSV doesn't have a hose running to the air filter.

Check the hose diagrams available elsewhere on this site and see if your hoses are hooked up correctly. Also make sure you know which component is which! I believe the Brad Anders website has pictures of most or all of the parts. Go through there, it really will give you a better understanding of your EFI system.

--DD

Ray Mital · 09-03-2006, 05:43 PM

Quote:

Originally posted by bd1308
take a look at your timing and dwell and trigger points, etc.

All of those will make your car run like absolute crap when hot.
b

...the condition you described is exactly what I had gone thru...the car running great, warmed up, stop for a short period of time. Get back in, acts like it's flooded. Then wants to stall out or wont idle well.

I checked the dwell and it was above 50. Corrected it and the car runs great.

bd1308 · 09-04-2006, 11:41 AM

I'm getting good

+1

Reason4Living · 09:51 PM

I used Darling's diagram when hooking up the hoses. It is not the hose that is connected to the cold start valve, but the other one that is shown connected to the air cleaner? There is no other place to hook that other end to so I assume it goes to the air cleaner. When I put my finger on the opening, I can feel it pumping air out.

I did recently replace all four fuel injectors so maybe the dwell angle needs adjusting. The car runs better now than it did but still has that stalling problem although it does catch itself now and putt putts until I press the gas pedal to get it to idle.

I will check the dwell angle and timing. I remember seeing an article on how to do it and as I recall, it required jacking the car up and removing some big parts out of the way. Not as easy as unplugging a hose that's for sure.