Running Rough - Missing - Lack of Power

[Wheel]

I am looking for some advice on what I believe to be a new problem. I took the Fiat out for a drive after it sat for a few weeks. I immediately noticed that it sounded weird, like a helicopter, and there was a lack of power….Argh! It sounds like it is not firing on all 4 cylinders.

The car is a 1982 Fiat 2000, fuel injected, 2 litre with approx. 44,000 kms (27,000miles). I put about 500 kms (300 miles) on it this summer. I put a new Magnaflow flow-thru muffler on this summer.

The work I did last winter included:
- Rebuilding the distributor, including the vacuum advance
- New vacuum hoses
- New cam tower gaskets
- Adjusted valve clearances with new shims
- New timing belt

Diagnostics and work I have done in the last few days:
- Replaced fuel filter. It was very dirty. See photo.
- Looked inside the gas tank. It is very rusty. See photo. Notice the pile of rust flakes and sediment in the bottom of the tank.
- Checked the fuel pressure. It is 39 psi with the pressure regulator vacuum hose disconnected. It is 32-33 psi with the pressure regulator vacuum hose connected. This seems to be high; I believe it should be 28 psi with the vacuum connected.
- Checked for spark. There is spark at all the plugs. When sparkplug wire #4 is disconnected, the engine idle does not change.
- Checked the vacuum advance. It moves.
- Checked for vacuum leaks. Could not hear any.
- AFM flap moves freely.
- Did a dry engine compression test; Cylinder #4 is 147psi, Cylinder #3 is 137psi, Cylinder #2 is 137psi, and Cylinder #1 is 145psi.
- I put in new sparkplugs and have run the engine for 30-45 minutes. The sparkplug from cylinder #4 appears wet with fuel and is white. The other 3 plugs are black. See photos.
- The exhaust produces watery black soot puddle on the garage floor. The exhaust is not smoky.

It was my plan to rebuild the fuel system this winter, because as you can see, the fuel system is filthy. Would the problem I am experiencing be related to the fuel injectors or is there something else I should also check?


Dirty Fuel Filter Contents


Inside the Gas Tank (notice the rust flakes and sediment on bottom)


Cylinder #1 Sparkplug


Cylinder #2 Sparkplug


Cylinder #3 Sparkplug


Cylinder #4 Sparkplug

[nalle]

My first quess is (really a quess) the dirt you have in your gas filter, you have it also in you injectors.
Open you injector lines ( rubber pipes are +30 years and needs to chance anyway) and look if there is any marks of rusty gasoline. If there are rust, you have it also in your injectors.
But as I said this is only a quess.

[RRoller123]

+1

#4 plug looks like it is not sparking at all. Agree that the #4 injector is likely plugged.

[spider2081]

I would disconnect the hose from the cold start valve. Add some hose so the fuel from that short hose can run into a quart container. Run the pump by moving the AFM flap. The fuel should be clean as the your new filter should not let impurities past it. This will flush the line from the pump into the fuel rail. It does not flush the 4 short hoses to the injectors or the injectors. I would add a filter before the fuel pump to protect the pump from the rust in the fuel tank. I uses a WIX filter #33248 between the fuel tank and the pump.it is also sold at NAPA.

If your fuel is looks clean I would check the temperature sensor in the coolant "T" and its connector. The approximate resistance of the sensor should be:

15 degrees F 7,000-12,000 ohms
70 degrees F 2,000-3,000 ohms
180 degrees F 250-400 ohms

[narfire]

me thinks pooched injector(s) as well. The tank should be at least cleaned.
When you take the injectors off, there is a small, fine screen inside that could very well be bunged up. As mentioned when they are off, change all the injector lines and use proper fuel line clamps when putting it all back together.

[Wheel]

Thanks for the advice.
I forgot to mention that I also checked the temperature sensor in the coolant "T". It seems to be working properly.
I guess I will start cleaning up the fuel system.
I am a little perplexed about the wet sparkplug on cylinder #4. Why would it look wet if it is getting spark?

[So Cal Mark]

#4 looks like an injector issue

[fiatfactory]

.

[majicwrench]

Obviously, at some point you need to clean fuel system.

As noted,that plug is wet. Is it fuel, or anitfreeze?? Fuel will evap off the plug in just a few minutes, antifreeze will not.
How's the cooleant level?? Was there smoke/steam from tailpipe??
Most injector problems would result in no fuel getting into cylinder. Being plug is wet, injector issue would not be my first thought.
If you have a way to get air pressure into cylinder, you could do that and see if get bubbles in radiator.

If not, and coolant up, I would replace that #4 plug and run it again. See if coolant pressure builds too fast, or smoke from pipe.

[Wheel]

I have already started on the fuel system clean up. Removed the gas tank and will get it cleaned up. The rest of the fuel system including the injectors will follow. I have to order some parts so it will be a while before I get it fired back up again.

In regards to the wet sparkplug on cylinder #4.
- Coolant level is up, no oil floating on top of coolant when I remove the rad cap.
- I didn't notice smoke or steam from the tailpipe. It is getting colder up hear in Canada, so it is getting harder to tell.
- The oil on the dipstick looks normal. I checked after the car sat overnight, not immediately after the car was running.

The cylinder leak test is a new one for me. I have an air compressor with a regulator.
Is this the procedure?
- Find some fitting to fit into sparkplug hole. Any suggestions?
- Put #4 cylinder at TDC.
- Remove radiator cap
- Put air into #4 cylinder. What is the recommended air pressure?
- Watch for bubbles in radiator. If there are bubbles, does this mean a bad head gasket?

[Wheel]

I got the fuel rail and injectors off the engine. Here is a photo of the inside of the short rubber fuel line attached to the injector for cylinder #4. I cut open the hose to see how much crap was in it. Seems like a lot!

[76was124]

Seems like a lot!

To say the least! Hopefully the screens saved the injectors.

[spider2081]

WOW I would not have expected that much rust to get through the fuel filter I wonder if it could be from the metal fuel line and rail after the pump.

[azruss]

this says you need to refurb the entire fuel system from the tank to the injectors. Assume this has also contaminated the pressure relief valve at the end of the fuel rail. Happy cleaning.