Back on 4 cylinders,but...

[narfire]

Craig, on the bottom of the pipe there was a small metal screen, there was on mine anyway. If you have an open pipe, I'd be thinking it has fallen off and perhaps something has been sucked up giving you a partial blockage. If you have air, try and blow out EACH section of fuel line.
I don`t know what the screen is made out of, but if it is ferrous, perhaps with an extendable magnet, you might be able to fish it out.
The lawn can wait... this is way more important as you will be thinking nothing but the Fiat while cutting and end up running over toys,dog bones, balls, rocks...ruining the lawn mower...thus having two problems.
Chris

[ga.spyder]

Thought I was going nuts,Chris.I called Mark,who is always nice enough to make time to counsel me! The screen and p/u aren't serviceable on later cars.The p/u line and return line are seperated from the main tank by a baffle!! No way to service or even look at it.I took Marks advice,removed the p/u and return line and blew shop air thru.Blew gas right out of the removed cap Unfortunately,no change.Next up,volume test.Tomorrow!! I am headed out on the mower.Kids,dogs,squirrels... Beware!

[seabeelt]

Consider the point of failure was the injector The others may be working, but not at capacity, I.e. it takes more pressure to squirt the right amount of fuel through a smaller opening (volume), so I would not rule them out at this point. Replacing one fixed the initial fault......... More food for thought

[ga.spyder]

Thanks Michael...I think !!!

[seabeelt]

Think of a garden hose with some pin holes in it (4) for the injectors. If you plug up the end of the hose, more water squirts out of the holes (crimping the return fuel line) if the pin holes have dirt in them, less water comes out of the pin holes (fuel additive build up on the injector nozzle) Seems like you have looked at most other things. We has an olds Auora that the injectors were working, but very poorly, making the service engine light come on. No code for a failed injector, but when the mechanic pulled them out and soaked them in cleaner, the amount of junk that came out of them was impressive. Once cleaned and reinstalled, no more issues. Just rereading the initial post and what fixed the car to make it run, it would seem that this avenue could be explored further.

[ga.spyder]

I am going to go ahead with volume test and,if that looks bad the filter and pump.20 minute job and I have all the parts.The scenario you bring up makes sense,I just dont want to go back until I feel I have explored all my options.I do feel like the gremlin is living in the fuel delivery system.I have a proven ECU on the way,but I really dont think thats the solution.Thanks for the suggestion,I appreciate any feedback.
Craig

[FiatBen]

I haven't read this entire thread as I really have very little interest in FI cars, but the original problem's description reminded me of an experience I had years ago. I bought a '77. The car started and revved like noboby's business. Paid the man and headed down the road. No power. Just absolutely bogged down under load. Limped it home. Csaba Vandor (of AutoRicambi fame) was in town a couple of weekends later. We got to tinkering. Turned out the intake cam was off about 10-degrees. We reset the cam to the pointer, buttoned it up and it ran like a wildcat with it's butt on fire!! It was like getting a new car!
Don't know if that helps, but one more thing to consider and check.

[bradartigue]

The Fiat FI manual specifies 36 +-3psi with the engine off and 28psi running with the vacuum hose connected to the regulator. I'm done posting on this, you can keep playing King of the Mountain on your own

What in the world are you so mad about? A disagreement on fuel pressure readings or how to diagnose a car? Stop being a baby or presuming I care about who has the right opinion - here's a hint: I don't. I want the cars the run. I've never seen a forum where posting regularly actually makes people mad. And you accuse me of wanting to be "king of the mountain?"

However, I'd be curious to know which FI manual he is talking about, because the one I have open in front of me says what I've been quoting, 3.0 +/- .2 bar, which is 42 +/- 3 psi. If there are discrepancies in the manuals
then it would be better to point them out then cry about who is right.

I cross-checked a VW guide and a Porsche guide, both use similar L-Jetronic systems, and both are near the same spec, 3 bar +/- .2 bar.

What does your FI guide say, anyone that has one?

[ga.spyder]

That is interesting Brad.I dont have a f.i. manual but I also dont have anywhere near that fuel pressure.Is that spec with the engine off? I may have to go back to looking at the fuel pressure regulator.

[Divers]

Craig,

Have you replaced the fuel filter? Was checking the thread and did not see that it had been done. Did you do the volume test?

At the risk of flaming from the injector purists Have you hooked up a pressure gauge dead head and checked to see if your fuel pump pressure is good. With the gauge dead headed against the fuel rail input, your pump should be able to get to at least 70 psi. Outside of doing this test which is MESSY....I just changed my fuel pump with the $85 dollar version from Autozone. Also....and I am rambling...just because you blew out the lines does not mean you have the volume you need flowing in the lines. When I removed my hard fuel lines I was amazed at the amount of crud that had reduced the inner diameter of the pipe. I felt very good when I replaced the input fuel lines with fuel injector hose.

It really does sound like your system cannot keep up with demand. That means something on the fuel input to rail is clogged.

Just my own input....

[fiatmike124]

3.0 bar = 43.5 psia = 28.8 psig. So....as for the pressure specifications i think that you are both correct.

[bradartigue]

3.0 bar = 43.5 psia = 28.8 psig. So....as for the pressure specifications i think that you are both correct.

I was not aware there was a competition being held. This alone is a good enough reason to have a metric pressure gauge.

I know that we're talking about a car that runs better when the return line is blocked off, which in every L-Jetronic book is a condition of a failing regulator and/or a failing pump or filter. Until this problem is addressed diagnosing "the next thing" doesn't make sense. Of course it could be this AND something else.

One man's opinion.

[ga.spyder]

I replaced the filter and pump this morning,and there is no change.The car still runs badly ,until the return line is crimped .Then it runs as it should,with the exception of a high(1200 rpm) idle.The fuel filter had a bit of rusty colored residue in it.Not many solid particles,mostly brownish tint gas,but a little.Pump seemed fine.I am tempted to instaal a small universal plastic filter before the pump,to see if the tank is nasty.Looking in the tank there is some surface type oxidation in there.Because of the baffle,I cant see the side where the p/u and return go in.All in all the tank looks relatively clean.I guess it is possible that some crap got into all the injectors? When I have high pressure at the rail they definitely dont feel clogged,the car runs well.
Not sure what to do next.The only thing I have spent money on is the injector.Honestly,not sure I needed it! Maybe buy a new pressure regulator?I am waiting for UPS to arrive with my loaner ECU,from a running car.I can rule that out in a hurry.I downloaded some Bosch manuals,and after reading up on the ECU,it does shorten and lengthen injector cycles.Could this be the problem?
If I dont solve this before the weekend,I am driving the car to Atlanta(200 mile round trip) for Italian Car Day.Have vice grips,and by God,I will travel!!!

[So Cal Mark]

It sounds like the other injectors may be partially clogged with rust particles

[Divers]

To clean out the injectors....could you apply direct 12 volts to each injector while cranking the engine? This way the injector is wide open and the gas pressure would free up and rust particles? Just a thought before pulling injectors and doing things the proper way.....I realize you Georgia guys like shortcuts Same as us Floridians!

Or better yet instead of cranking the engine.....apply 12 volts to injector....turn the key to run and then manually hold open the AFM flap....then put vice grips on the return line...that should build up a good amount of pressure on the injectors.