Alfa Romeo Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
143 Posts
Discussion Starter #1
Hey all, help needed with a couple of problems please.

Problem 1. I was going through Greg Gordon's site trying to fix my fuel injection problems, but I can't get on the site in the last couple of days. Maybe it's just a problem from Australia? Can you Northern Hemisphere guys still get on to it.? Does anyone have the information in a file maybe?

Failing that, maybe someone has had the same problem as me. (Deep breath)

We're talking about an Alfa 90 here, mechanically the same (for our purposes) as a 75/Milano 2.5 V6.

Problem 2. I've never had a problem with starting or running with this car in 3 years of ownership. I've started to turn this car into a track car. recently I installed a surge tank. A week after that at a very warm practice day I had problems starting the car when it was hot. Ambient temperature was about 35celsius/95 F. Car was running at 110C/230F. I had major problems starting the car, but it would start after sitting in the shade for a while. Next day was early 20's C/73F, car started every time, ran like a dream. car was running at 90C/194F all day for 80 minutes of track time.

A couple of weeks after that, I was running the car on the road during a very hot day, 37C/98F. Car was running fine until I stopped, then wouldn't start again. Eventually got it going, considered my options. A week later, the car ran fine for a couple of hours running around town in mild temps. Left it for about an hour, got it the car again, got 100 meters down the road and she just stopped. Would occasionally start, but then stop again 2 seconds later.

Have started to go through Greg Gordon's site, I think I've eliminated air leaks. car started just fine today, seemed to be running okay, then as soon as it got to about 60C/140F it just died and wouldn't start again. (That's not quite true, it started eventually but died straight away.)

Please help, I've got a track day in two weeks at the second best track in Australia (Phillip Island), and my Dad's coming from overseas to share the car with me. I need this fixed ASAP.

Thanks guys

Attached a pic of the car racing a few weeks ago to hopefully inspire answers
 

Attachments

·
Registered
Joined
·
143 Posts
Discussion Starter #3
Excellent, thanks for that, I desperately need it.

Update, I went out again, got car started, (50C), quickly unhooked TTS before it got too hot. Seemed to run fine, got up to max temp before fan came on. Ran for 20 minutes. I plugged connector back in while it was still hot, expecting it to die, but it still ran fine. Was thinking it was definitely this, but obviously not too sure now.

Check AAV next?
 

·
Registered
Joined
·
3,372 Posts
Next time it won't start try unplugging the Cold Start Injector. Maybe one of the sensors is bad and you are getting too much fuel?

Kevin
 

·
But Mad North-Northwest
Joined
·
10,791 Posts
Seems like too much of a coincidence that it started happening soon after you installed the surge tank. Perhaps that messed something up with the fuel flow.

I know that it's occasionally harder than usual to hot start my Milano. Once it does start I typically hear a rumbling/bubbling from the fuel return line for a few seconds. Apparently this is semi-common and is due to the hot soak vaporizing some of the fuel in the lines...the noise is the vapor bubbles working their way back into the tank as the fuel flows through the return line.

Perhaps the addition of the surge tank as exacerbated this same problem for you somehow?
 

·
Registered
Joined
·
143 Posts
Discussion Starter #6
yes agreed it could quite possibly be that the surge tank has exacerbated the problem. The surge tank is only 1 litre, so it's possible hot fuel returning to the surge tank is heating up the fuel too quickly. that was what I was thinking until it recently started ummm, not starting, then dying at 60C, which is not hot at all.

I'm wondering if I can run the rail return line straight back to the main tank instead of the surge tank, and also have a return line from the surge tank. I'm not convinced this is the problem though. Maybe it is just a coincidence

Until Greg Gordon's site is back up, can anyone remind me exactly what the TTS actually does?
 

·
Registered
Joined
·
3,372 Posts
It is used to tell the ECU whether or not to fire the cold start injector (that is why I suggested disconnecting the CSI). If the coolant temp is below 86F/30C the CSI will fire during starting, if it is above that it will not.

Kevin
 

·
Registered
Joined
·
3,506 Posts
If it were a Motronic hot-start problem, I'd suggest the Coolant Temperature Sensor. Does your car run on an LJet system? Fuel issues (flooding vs. too lean) are usually identifiable by adding a shot of fuel, or ether-based starter fluid, into the intake. If the system is too lean, then there will be a quick response from the engine. If it is too rich, it still won't start. Trying to help....

Michael

Hmmm. Just read Kevin's comments carefully. I think this means that if the coolant sensor is reading too high resistance (cold indication) then the cold-start injector might fire and flood a nicely warmed up engine. Seems like a good candidate to me. The Motronic CTS specs should be readily available on the net, and I can't remember just now. I'll look them up, though.

And now that the board is back from its nap...

In a post by the esteemed Fred Di Matteo from the digest.net archives (marvelously useful):
Alfa 164 Notes

> John, I would check the resistance of the coolant temperature sensor
> when it is at full operating temp. and just before you start it in the
> morning when it usually acts up. When fully up to op yrmp it should not
> be less than 250 ohms. At 68 degrees F. it should be not less than 2000
> ohms. Be sure that the connector is secure on the sensor and that there
> is plenty of slack between it and the chassis. That's important in
> 164s. Good luck finding the problem, the cure should be easy.
> Fred Di Matteo Fort Myers Florida USA AROC Tech.


Back to your regularly scheduled programming, already in progress...

...and another thing, to test whether it is getting too much fuel, can you pull the fuse for the fuel pump and continue to crank? That should allow the engine to clear a flooded condition. If you have too much fuel, it might sputter and then die when it passes through proper mixture ratio on the way down to straight air. It would be an indication. I like indications.
 
1 - 8 of 8 Posts
Top