engine dies out - overheating?

[geecee]

By the way, I have a new throttle switch and I'll replace it this weekend but that's not it. I just know it.....

[81SPIDERMATT]

reading your tale of woe made me remember mine... was convinced it was heat related and because of the heat something in the ignition system was failing.... turned out to be the fuel pump... ran great... got warm... died... gotta be hot electrical.... nope.... so i will pass on advise that helped me ... "at breakdown verify spark and fuel"... for me a fuel pressure gauge told the story of a failing pump.... i am by no means one of the smart ones... but sometimes first instincts are on the money.... you stated in your first post that it seems like it was starving for gas.... chin up... deap breathes ... Matt


http://fiatspider.com/f08/viewtopic.php?f=3&t=19110

[geecee]

Hi Matt, I just read the tread you posted. I feel your pain.
See, when i bought my car it was not running. occasinally starting but not holding on but for a minute. So we did clean the fuel tank, and I mean took it to a shop and had it cleaned inside and out.. Put everything back together but not before gently blowing air in the lines. the carbon cartridge was leaking carbon and plugging the lines.Replaced fuel filter and replaced the pump as well. That brought her back to life and did ok for a while. Just like for you,great on short distance trips running errands. Then I gave it a try taking it to work. It messes up only onmy way back home. It's like she hates the 5 o'clock commute a decide to turn herself off till is later and safer to go home.

This last time when it started, I drove her to the shop. The guy said that he did heck the airflow and found nothing there. Also he claims he checked for leaks...none. He claims it' s bad throttle position switch...possible?

[81SPIDERMATT]

that would be a guess on my part to say yes .. as stated i am not the one... just speaking from my own limited experience .... you said you have a new throttle switch .... guess since you have it you could throw it on and see... but that is not the way to find the problem.... at breakdown confirm spark and or fuel... if it dies it dies for a reason... isolate the reason...

[geecee]

Well, that was just a waste of time!
I did replace the throttle position switch (which was probably ok) and test drove the car. Same issue but I can rule out overheating at tis point.

This time I noticed something....it started when I gave more gas. I drove her around the neighborhood, and it did it when I was just about home. On the driveway I could make it happen in neutral and keeping the accelerator pedal revving her up at 3000 RPM. Basically it runs at 3K, then cough it up and drops to 1.5-2.1k and then up to 3k again and so on and so on. My foot never moved...

So what is it, starving for fuel or for air?
I checked the pump, just because I replace it the old one that was clogged with junk. As I said before the new pump came after I had the tank cleaned, and I replaced the fuel filter as well. The new pump is from eBay but it is a BOSCH 0580464070FPP...reading a post from Brad Artigue...is the righ one for the job.

Now what? I know I can drive her as long as I keep below 3000 rpm...how fun!

[rja]

just a stab-fuel press reg allowing sufficient flow back to tank? w/o this, pump can 'vapor-lock' to elicit similar symptoms?

[geecee]

just a stab-fuel press reg allowing sufficient flow back to tank? w/o this, pump can 'vapor-lock' to elicit similar symptoms?

Possible.. I remember going through the sto-by-step troubleshooting guide for FI systems, but that was last year. The car would not start at all then and that's when we assessed that it had to be the pump...which it was.

Believe it or not I feel pretty good now because if if I can't drive the darn car, at least the "5 o'clock syndrome" is not a random occurrence. "If you know how to make it fail, now you can fix it!" - my dad

[81SPIDERMATT]

how did you check the pump this time??? renting a fuel pressure gauge will help

[majicwrench]

You need to TEST otherwise you are just guessing. LIke was said, hooking a pressure gauge up is a good first start, and watching it till car stumbles. Or, when car dead, CHECK FOR SPARK and CRACK FUEL LINE and see if there is fuel pressure.
AND get a new "mechanic".
Keith

[geecee]

You need to TEST otherwise you are just guessing. LIke was said, hooking a pressure gauge up is a good first start, and watching it till car stumbles. Or, when car dead, CHECK FOR SPARK and CRACK FUEL LINE and see if there is fuel pressure.
AND get a new "mechanic".
Keith

Definitely taking your last suggestion Keith!

Troubleshooting is what I do for leaving (in a very different field), but I do understand the methodic approach to it, and how to analyze a problem in a progressive and systematic way.
We did all of that following a great .pdf diagnostic guide on troubleshooting Fiat Spider FI systems. I believe is from FIAT itself and I found it last year on this site. Still have the MS Word file if anyone needs it. At that time my Fiat would not start or start or died in a few seconds. So with the diagnostic and a rented pressure gauge and hand pump from AutoZone, we determined that the fuel pump was bad (no fuel pressure at all, but voltage at the pump was good) and decided to clean the whole system.
We did not touch the injectors because that was too much for us. I swear the tank/lines/filters/pump, all had been clean to spotless or replaced. The fuel pressure regulator was not replaced or taken out. We tried but the thing wouldn't come off due to rust, so we left it alone.
Finally the car was running and all was fine except that on longer trips (~ 6-7 miles to work) but only on my way home it started to misbehave.
That’s when I started this tread….I honestly thought that there was an overheating issue and replaced the two temp sensor (lower radiator and one on the T piece) as they were malfunctioning.
This car had been inactive for about 15 years abandoned according to the PO, and he also had it for about another 5 years and did nothing. Sometime is a wonder that she works at all.
So, I think we are going back to the diagnostic guide and start all over… rent pressure gauge, etc. That should clarify more on the fuel part.
Keep you posted, and sincerely thank you for your replies. Moral support is priceless.

[geecee]

Ad you technical knowledge...greatly appreciated.

[geecee]

OK Knowledgeble Ones, checked for spark, and obviously good as the car runs.
Checked fuel pressure....28 psi, constant even if pinching the line under the fuel pressure regulator.

Now? According to the diagnostic it should read 40 psi or otherwise it's an issue with either fuel filter or pump.

I remember reading here that 28 psi was good, so....? Just need someone to confirm before I mess with filter or pump.

[81SPIDERMATT]

mine was 30 then would jump to 38 when mashing the gas pedal under load.... not sure about revving in the driveway what it should be.... others will chime in about your figures i hope>>>>> .... the question is did it have spark and was that the pressure at failure????? as stated seems to be fine then all of a sudden it is not.... it is at that point when it is failing that that we need to know about the spark and the pressure...... ??????

[81SPIDERMATT]

you can put the gauge under the windshield wiper and see it thru the windshield as you drive to failure .. and carry a spare plug so you can quick like a bunny see if you have spark at failure

[majicwrench]

Testing it while running does you no good. LIke was said, you need to test while it is not running.
That said, 28lbs not really enough, and it SHOULD go up when you pinch return line. But get it to fail, test!!
Keith