My 7 runs great... but after you warm it up and shut it off, it seems like it floods... and after that it gets warm for no real reason... any takes? Thanks!

 

Heh... a little more information would be helpful. Does it crank, does it click? Does the engine spin abnormally quickly after it will not start? Any information is good.

 

I have a 2nd gen and the same problem happens. I have searched these archives and have found nothing. I have found that as long as I dont put additives in the tank, and I don't use gas with ethanol in it. The car usuallay starts.

This is wierd, but the car always starts cold. If I drive it several places, or for long distance on the interstate and shut it off and then try to start it, it will initially attempt to start, but will die and will not start for some two hrs. if it doesn't start on the FIRST ATTEMPT. I have found my key is to make sure the car starts on the first attempt. I will run the rpm's to about 2500 to 3000 far a few secs and the car runs fine. I believe it has to do with the low compression, etc. This is what has worked for me. Please let me know if this helps, or not. It is EXTREMELY frustrating for the car to not start.

It ALWAYS starts when cold! Go figure!

Jim

 

Bad compression that was my problem

 

I have the same problem. If it doesn't start on the first try I have to take out the EGI fuse and turn it over a few times and it will start right up. I am guessing it might be low compression. The car will turn over but it seems like it is flooded. Although after a few hours or so it starts right up?

Cold start = no problem, Hot start = no start

 

leaky injectors

 

I am having the exact same problem. My 88 turbo starts fine cold, but recently will not start at all after it gets hot. Died on the road the other day and I couldn't get her going.
I will try and replace the plugs, check injectors, and check compression. I also have recently installed a upgraded ECU from Digital Tuning Inc. (i don't know if this has anything to do with it or not) My engine has 106K miles on it, so compression may be an issue.

 

99% of the time leaky injectors and poor compression causes the warm no start problems.

the other 1% is related to a blown transistor in the ECU, but make no false assumptions, the blown transistor causing the problem is very very very very very very rare and related to someone testing the BAC with a testlight rather than a digital multi-meter.

 

I had the same issue in my NA to Turbo conversion, turns out it was a ecu\wire harness problem.

 

how can you fix low compression?

 

my car starts fine from cold start but after driving it for 10 minutes or so it shuts off and wont start at all after that until its cooled off then it starts up fine also sometimes when it shuts off if i hook up jump cables to it and jump start it it will start up and when im in neutral i rev it up and let the rpm's go back down it almost dies unless i give it gas are all these problems related please help want to get my 7 back on the road for summer also its a new engine with only 35,000 miles on

 

You rebuild the motor

 

if i have a rebuild and it does that then what?

 

Well in order of what to do first:

1. Check compression (this is done at WOT with the coils disconnected). If it is below 90 at any point consider a rebuild (unless this is a new rebuild with less than 2K miles on it, then it is normal for some flooding to occur).

If the compression is okay:

2. The injectors should be taken out and professionally cleaned ultrasonicly as well as for flow. This is not sidestepped by dumping injector cleaner in the tank. At best injector cleaner in the tank, running at 2 or 3 times the recommended levels might wash a little crud out, but not really clean a stuck injector. The stuff sold by oil change shops is even worse, and won't clean an injector if their life depended on it.

If compression is good, and the injectors have been cleaned, and the car has a recent (within 10K miles) 60K tune up (plugs, filters, fluids, O2, etc)

#3 Then I would look at swapping ECUs.

 

Ok, mine (91 TII) has a hot start problem.

However, it ALWAYS starts if I floor the pedal and cut the fuel injectors.

Does that lend it self to being something other than compression?

James

 

my car has the same problem. it cranks but doesnt start and the coolant buzzer goes off and doesnt go away.

 

no... do the above tests in order.

Remember flooring the accell (weither the engine is running or not) turns the MOP on full, bringing up compression, if there is a bad seal

 

REALLY, very interesting. Even in a s5?

James

 

I was told the ECU on the S5, cuts fuel but still ramps up the MOP on WOT when starting, so I am assuming yes.

 

Some more data: I replaced the plugs, checked timing and BAC valve. The engine idles down(almost dies) when I remove the connector on the BAC valve when it is running, so I think its working. I also took out the Digital Tuning Chip and put the stock chips back in. Still have the Hot start trouble, but removing the EGI fuse, cranking a bit, and reinstalling the fuse, does get it started again. I tried a compression test with a testor I purchased at Auto Zone, but I'm not sure if I did it right or not. I read somewhere you have to pull out the little check valve in the hose fitting or something? on the testor? How do I check the injectors?

 

Correct me if I'm wrong, but can't this also be caused by bad coolant seals? The engine warms up, building pressure in the coolant system, and then when the engine is shut off the coolant leaks into the combustion chamber.

-Joe

 

It would seem that it would smoke like hell if you let the car cool down and restart though. That would give you an indication it is burning something on start.

Do you have any smoke on cold starts?

James

 

A little puff of smoke on the cold start which has been there since I owned the car(8 yrs). Probably a little oil burning off? Nothing else to speak of. Even when its flooded and I've been cranking,flooding,cranking etc.. It does not seem to make much smoke. What about the leaking injector idea? I need a little assistance on the compression test procedure, I'd like to rule that out as a possibility of the problem.

 

again that would show up as a low compression issue

 

Hey Icemark...I was curious about that. So if I have a problem with the coolant seals in my TII, I will always get lower compression as a result? I get solid compression at 105 PSI front and back on all 3 rotor faces. The car starts immediatly every time I crank it, and there is no smoke from the exhaust. The only thing that worries me is that I was getting some air coming up when I start it with the radiator cap off. This may have just been air trapped in the system though. What are your thoughts?

-Joe