Back on 4 cylinders,but...

[So Cal Mark]

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

[ga.spyder]

As for me,I appreciate what both of you have done to help me thru this.I am closer to the solution.To me,the pressure and volume are a connected item.At the extremely high pressure(return crimped) I seem to have enough volume to satisfy the need of the injectors.The issue seems to be why at low pressure is there not enough volume.Here is my next course of action.Please..if you have input and dont want to post it,contact me via email nuker598@yahoo.com
1) change the fuel pressure regulator to see if that will bring pressure higher to satisfy the injectors(I really think my pressure reg.is ok per manual specs but this is an easy item)
if that doesnt work
2) do the manual specified volume test and check the strainer in the tank
still no issue found
3)Start testing/swapping to see if I have an ECM fault.
4) involves either carbs and manifolds or lighters and gas

[Divers]

Craig,

I don't like testing stuff that is 30+ years old. That is why against the views of some...when I was going through things I decided to just replace and be done with it. So.....when I thought I had a fuel issue, I pulled all the gas lines from tank to rail and replaced. Even if not the problem this time, you still are going to have to deal with this...eventually. While I was in the "mode" I bit the bullet and replaced all the lines with high pressure injector line (and fuel filter). Also, drained tank and inspected. I also changed the fuel pump but that was probably a little overkill (but for $80 bucks it was money well spent). That way I KNEW without any doubt the volume and pressure (with gauge) were good. I am by far not an expert on these cars BUT replacing old crap with new stuff seems never to be a bad idea when the cost of doing so is very low. Good luck and keep posting!!!!!!

[ga.spyder]

Thanks Robert,as I have been going thru this I have been replacing some(not all) lines,etc...I swapped the fuel pressure reg. this morning.No change.I didnt think that was my issue,but leave no stone unturned. I changed it and drove the car,no acceleration,rough running with systems untouched,running great with return line pinched part way. Frustration!!
It seems to me,that I either am not getting the volume of fuel the injectors need,or the injectors are firing incorrectly.John Erskine is sending me a ECU to try.Also,fiatmac(Stan) is coming this way next week.He has a better grasp on the ECU issues,and has graciously offered to help.I am pissed to have missed FUN with my car,and Italian Car Day here is looking badly too.Fall color,cool temps,and garage bound(unless I clip on the vice grips!!)

[kmac33]

That's what you get fur havin' one of dim new fangled fuel injected Spiders Put on the vice grips, Duct tape em in place and drive!
Hope you get this sorted soon. Again, if the Spider isn't running right for Italian car day, you are welcome (and encouraged) to either drive my Spider or ride the Guzzi to the event so I can get them both there.

[Divers]

Kevin,

Driving YOUR spider! That's like sleeping with another man's wife

Robert

[Gunsmith]

Well I picked the Spider and my problem was the ignition pick up assembly and ignition module and fuel filter at least one of them anyways I had him replace them all and she is running great! Good luck man.

[seabeelt]

I'm going to stick my neck way out here because I certainly know a lot less about these FI systems than they do (Mark and Brad), ( and I'm with Curly on this one). Here goes. From a mechanical engineerig fluid mechanics standpoint we need a certain volume at a certain pressure to operate correctly. So doing the math as an example ( and using an arbitrary figure for volume since I dont know what it is) and using 35 psi for easy math. Correctly operating 35 x .5gpm ( gallons per minuite ( dont shoot me I know its not correct)) = 17.5. If we have to increase pressure to achieve the same 17.5, it means volume is lower ... simple algebra. So if volume is lower, ther are only a couple culprits, fuel filter , fuel line, or fuel pump ( and yes the pump will work harder to increase the pressur in the case of a restriction somewhere in the line.) I'm going to rule out fuel regulator as you hae already changed that, next is the fuel rail, and of course the individual injectors which we cannot truely rule out since you have a much higher psi to make them work for the engine performace. (when was the last time the injectors were cleaned /and or replaced?) Just some food for thought...... Check each one systematically starting at the fuel tank ( test, test, test) check and retest

Had a car once where a small piece of paper somehow ended up in the tank. car ran OK at idle but ran like crap once you stepped on the gas and the paper got sucked up against the fuel intake. Took forever to figure it out,

[ga.spyder]

The volume figures are pretty compelling.I plan to replace the fuel pump and filter,as I have a new one of each.If that doesnt do it,I am headed to the tank.The solution lies in there somewhere.I have personally eliminated the injectors.1 is new,the others seem to be working fine.I have tested all with a noid light,and when the pressure is high,the car runs excellent.No,I think volume is the culprit.Hey,Im closer than I was!!
Divers...have you seen kmac's Spider? For that matter ,have you seen his wife!! Both are excellent specimins.Thanks Kev,I may have to take you up on driving the Spider to ICD.
Gunsmith,glad to hear you are back on the road.I have been thru the ignition and I am sure my issue lies elsewhere.

[narfire]

Before replacing the pump, I respectfully suggest pulling the gauge and the screen. WAY easier fix..
If you do replace the pump and filter, if you have air blow some through the lines and see what if anything comes out.Disconect at the engine, filter,& tank though.
Chris

[ga.spyder]

Thanks Chris.By''guage and screen'' you do mean the parts in the tank? I have ignored everything in the house for the past week.The grass is knee-high!! I am taking tomorrow to catch up and step away from the car.I will get back in there Sat. morning,and pull the sender/pickup first.Then possibly pump and filter.If that doesnt fix it,I have 2 ECU's coming on Monday.I really think my problem is between the tank and the injectors,but....

[narfire]

Thanks Chris.By''guage and screen'' you do mean the parts in the tank?

Yeup, the whole works comes out as one. There is a small screen on the bottom of the fuel pick-up. Has your tank ever had rust issues and been cleaned? Still same tank as when new?
Perhaps over time you have picked up some crap gas with a bit of water in it. I'm thinking the humidity there is not the greatest for a fuel tank of our vintage and over 30 years rust has started on the inside, flaked off and bunged up the intake... Think Mark was onto something there..

[ga.spyder]

Everything I do and find,I am hopeful that it will be 'it'.When I can keep fuel at the injectors the car runs perfect,so I can safely eliminate ignition,etc..The tank has never been dropped or cleaned in the time I have owned the car.Pretty safe to say it is the original tank.Since changing the fuel pressure reg. didnt work,I think the volume theory makes sense.Mark suggested it to me several days ago(he also suggested crimping the return line to see what happens).I think I am close to resolving this!

[Europa]

I think I am close to resolving this!

Awesome! Keeping my fingers crossed.

[ga.spyder]

I know I said I was going to mow grass,but... I pulled the 6 nuts and removed the sending unit.It came out very easy.So,what should I see.The unit and the tank have a bit of surface rust for lack of a better description,but look pretty good.Peeked in with a flashlight and it looks clean.But where is this screen/fuel pickup? There is a baffle seperating the 2 sides of the tank so I cant even see the fuel outlet.Am I missing something or did I do something wrong?? I was hoping for some sort of partially clogged screen or strainer.