help with fuel injection

[dalvis]

My mechanic is stumped (and so am I). My goal this year is to get my 83 running well. Problems that existed at the beginning of the year:
Poor gas mileage (19 mpg highway)
Rough idle when cold
Could not get a proper valve adjustment because the head needed to be rebuilt.

So I had my mechanic rebuild the head hoping that would fix everything.
After about 500 miles on the rebuilt :
The gas mileage is still bad (maybe a little worse)
The engine would not rev to 4000 and started running rough. The guage on the oil pressure stays low. It never hits 55.

I took it back to my mechanic and here is what he has done:
1. New fuel pump and filter (OEM)
2. New oil with the lucus stabilizer
3. Replaced ignition module
4. Replaced ignition wires
5. Replaced magnetic pick up
6. New spark plugs
7. Replaced AFM with a known good used one

Replaced throttle position switch with oem, but the car runs better without this connected.

After all of this, the engine will rev to 4500, but there is little power above 3500. And it revs slowly past 3500. I am using premium gas to see if that will make a difference. The gas milage is still not good (around 20 mpg hiway)

The mechanic has been working on fiats for 40 years and he is frustrated (and I'm quickly getting there)

Any ideas?

Dwayne

[dalvis]

Other things:
Replaced CPU with known good used one
And checked injectors

[giuliot60]

Sorry to hear you're having issues. I know how frustrating that could be. It may not be FI related, but there's a good chance that it is. This link was very helpful when I had issues: http://www.hiperformancestore.com/Ljetronic.htm.

You may also want to check out Artique's FI tune-up and maintenance manual and the Bosch troubleshooting manual. (Artigue_FIAT_124_MM.pdf, and Bosch L-jetronic Fuel Injection Troubleshooting, Maintenance & Repair Master.pdf). I'll send you the PDF files if you don't have them.

[majicwrench]

First thing I would replace would be your mechanic. Not trying to be a smart-ass, just being frank. It is not a very complicated system, and any competent technician would be able to figure it out in a timely fashion without just swapping parts.
Keith

[So Cal Mark]

I agree, your mechanic might have been working on Fiats for 40 yrs, but has he actually fixed any of them? Since he had the head off, I'd start with checking the cam timing. If the engine won't rev, either the cam timing is off or the exhaust is plugged. Has he checked the basics? How much manifold vacuum does the engine have?

[GeorgeT]

Clogged catalytic converter?

[dalvis]

Guess I will look for another mechanic. Any sugestions in the Atlanta area?
I replaced the exhaust with 2.25 pipe from the header. There is no catalytic converter, just a resonator.

Thank you

[ga.spyder]

Dalvis,who are you using in the Atl.....Southside?? If you would rather not go public,pm me.
Craig