Engine seems starved when I try to drive- cant rev over 3200

[michaelgough]

81 FI car cranks quickly and idles perfectly. When I try to drive, it seems stuck in the mud. Cannot get engine to rev over 3200, even with the clutch in. Replaced the fuel filter, but no change. What should I try next? My fuel injection knowledge is poor. It drove great for years. This problem happened pretty quickly. Live in Central Oregon and Fiat mechanics are scarce, so I'm probably going to have to figure this out myself. Thanks in advance.

[ORFORD2004]

Jam flap in the airflow sensor. Clean the track of the airflow sensor with contact cleaner.
Temperature sensor in the T in front of the engine.

[18Fiatsandcounting]

A few other possibilities: plugged catalytic converter (if you have one), ignition timing got out of adjustment, bad (or plugged up) fuel pump.

Does the power seem OK at lower revs, like 2000 or so?

-Bryan

[michaelgough]

Orford, I will check the flap and contacts.
Bryan, I will check on power at 2000 rpms and get back.
Should my next step be to check the fuel pressure?
How would I check the catalytic converter? Disconnect it?
Thanks so much guys, I'm lost!
Michael

[18Fiatsandcounting]

Given that the loss of power happened suddenly, that points to the problem NOT being the catalytic converter, so I'd check other things first. I just mentioned it as a (remote) possibility.

Lack of sufficient fuel pressure to the injectors could be the issue, so it wouldn't hurt to check that, especially when revving the engine over 3200 rpm.

If your ignition timing is wildly off, that would cause an issue, but again since the problem happened suddenly, that's probably not the issue.

So, check the air flap as Orford suggests, and the fuel pressure as you suggested. One thing that can happen is crud in the fuel lines / tank that plugs up the inlet to the fuel pump, and the solution there is checking the gas tank for crud, cleaning the lines, and perhaps a new fuel pump.

One other thing that can happen to cause a loss of power is a vacuum building up in the gas tank due to a venting problem, but that usually takes some time to build up the vacuum before you start losing power. The check for this is simply to loosen the gas cap slightly and see if the issue goes away.

-Bryan

[ORFORD2004]

https://autoricambi.us/1966-1985-fiat-1 ... -ignition/
Check the wiring of that thing.

[michaelgough]

18Fiatsandcounting wins the prize. I think.

Replaced fuel filter 1st. - nada
Cleaned and inspected , sprayed contacts in air flow assembly - nada
Disconnected the catalytic converter - engine ran as it should - before would bog down and not go above 2400

Any suggestions on where to take the exhaust system from here? All knowledge is welcome.

[18Fiatsandcounting]

Weird, this is the 3rd plugged catalytic converter that I have run across in the last year or so.

You can install a "converter test pipe" (available from some of the vendors, and if that fixes the issue, you can decide whether to cough up the money for a new catalytic converter or leave the test pipe in place. Your choice may depend on whether you have to get the car smog checked.

-Bryan