93 festiva problems, input please!

[2ndmouse]

This car has been gagging and acting like its out of gas on and off, and has lost all spark more than several times. The code flash was the crank sensor, and the new distributor fixed the spark problem. We still have this gasping bucking and sputtering problem when its put under load.

Replacing parts doesn’t bother me, those are more new parts I don’t have to worry about later.
I'm running out of stuff to replace….. and its still doing it.

Please read the list of stuff I've put on and done, and post a comment or opinion, I'd greatly appreciate the input.
~~~~~~~~~~~~~~~~~~~~~
NEW;

>Distributor, coil, ignition module.
>Air filter, fuel filter.
>Plugs, wires, rotor & cap.
>Compression test; 150psi on all 4. A yr ago it was 170 on all 4.
>Good hot blue spark on all 4 plugs, arcs 2" in a spark tester.
>Fuel pump sock clean.
>Gas tank checked, no water. I put a bottle of dry gas in for kicks.

I tried this with the fuel system;
>Fuel pressure regulator, if you disconnect the manifold vac line and plug the manifold end, it will run OK in 1st gear, 2nd gear.(under load) 3rd gear only if it is not under load [cruising] 4th and 5th gear acts like it is starved for gas.
Plug it back in, you cant get anywhere even in 1st gear, it acts like its out of gas, sputter gag choke surge up down ect ect.

> Clamping the fuel pressure regulator return line off makes the engine barely run at all.
since I did that, now it wont run worth a damn even if you plug the vac line on the FPR.

>With everything hooked up "correctly" the Engine will start easy, idle smoothly. Rpms can be raised normally providing you don't "gun" the throttle, if you do it will bog out.... but wont stall.

>The only thing left in my head to replace is the fuel pressure regulator, the fuel pump, and the injectors.

>I plan to do a leak down test once I fix the tester in a day or 2.

I'm ready to set it on fire….. any suggestions what to try next?

[kcline40]

Have you tried not tightening the gas cap down, sounds crazy but I have found when my festiva used to buck, it was low on gas, the fuel pump was working so hard to pull that little bit of gas I had in the tank to the motor that when I released the pressure from the cap it ran like a champ again. I have heard of vaccum lock in Ford Explorers to I think it's from using an after market gas cap. I hope this helps if not sorry.

[FB71]

If that happens with the gas cap, the cap is defective. Have you pulled the pump and inspected the sump filter (sock)? Chances are, its partially clogged with silt.

[mechanicaldj]

i know this seems silly

have you checked your PCV valve lately?

the possibility is that moisture from the engine is getting into your distributor cap

or even check the seal on your distributor and the cap including the vent hole

[gdawgs]

Mine acted similarly when I had a bad muffler. The exhaust had nowhere to go, so it bucked and had no power. Just something else to check.

[2ndmouse]

I solved the problem about 95% with a new fuel presure regulator, bu the intermeittent "gag" it has if you clutch it wrong might be the cat converter getting slowly clogged up, or just injectors in need of cleaning out or just plain worn out injectors.

also I found a few large bubbles of water in the tank and dry gassed those away.

for now its running as well as it was before the problem. I ran a few different fuel pressure tests and the pressure is where it whoudl be by the book, between 35-45 psi depending on how your testing it.

there isnt much left to replace but fuel injectors and a new cat. (but it passed a PA emissions with flying colors... wtf?) I did also clean a ton of crud out of the throttle body.

probably was several problems all coming to a head from hard use, she has put over 15K on it in 10 months.

tough little cars!