1993 Ford Festiva Problem

[Festiv93]

I have a 93 Ford Festiva. I have replaced the fuel filter so far, but still have no idea whats going on. It starts up and runs just fine, but when I drive it I am only able to put the gas pedal down a quarter of the way. Anything more than that it wants to cut out. When i let off the pedal a bit I feel the engine smooth out. But its just annoying only being able to take off at 1/4 throttle, and when going up hill i have to down shift because I cant give it enough gas to keep it up to speed with out it cutting out. Side notes: Like I said earlier the fuel filter has been changed. The owner before me removed the catalytic converter for some reason, and the exhaust has a huge leak back by the muffler...not sure if the lack of back pressure is causing the drop in power... codes that were read off it were 2 oxygen sensor codes and a "fuel system lean" code which I believe is making it smell like gas in the exhaust from the computer dumping more fuel, or it could be the lack of a catalytic converter... anyone have any ideas?

[CrookedHalos]

Mine pretty much had the exact same problem. I swapped out the MAF sensor from the junk yard and it worked like a charm. My friend had the problem on his Festiva and he told me to check that, I would have never figured it out on my own haha and the guy I bought it from thought the valves were burnt.

[FestYboy]

also look at your ignition system... especially arround the coil tower.

[Festiv93]

Well I dont know if this means the MAF is working but when its idling and I unplug the MAF the car dies, but when its plugged in again its fine. And what should I be looking for on the ignition system? I wish I had a parts car laying around to test this with as parts on these cars are hard to get ahold of and cost some $ if you are able to order them.

[Icedawg]

Your plug and unplug test of the air flow sensor just tells you it works at idle. Check to see that the vane that opens as more air flows is free to move easily through the full range of motion, they can get sticky. Just stick your fingers in when it is off, and push away at the vane. You could also have a fuel pump problem, where the pump works ok at idle and partial throttle but can't deliver as demand goes up at higher throttle. To test that you need to put a fuel pressure gauge on the fuel line with fuel still delivered to the engine,(i.e with a T-insert in the line) and have someone floor the throttle while someone reads the pressure. If it is the pump the fuel pressure will drop well below 30 or 40 psi once the problem shows up.

[Festiv93]

Ok will try that too. Hoping its not the pump. If I accelerate and slowly push the pedal down it will rev up just fine. Its only if I try to press the gas down too fast it will spit and sputter. Also if I press the pedal down fast and hold it WOT it will kill the engine??? But slowly pressing the pedal down will allow me to open the throttle all the way?

[DriverOne]

Re: 1993 Ford Festiva Problem

It almost sounds like a timing issue to me, and an 02 sensor.

[Festiv93]

I was wondering about the timing being off. And like i said the person before me got rid of the catalytic converter and I assume the 2nd 02 sensor used to be down there? I only see one and its the one in the exhaust manifold

[DriverOne]

There's only one o2 sensor. I've heard that you can use a 12" glass pack in replacement of the 'cat, which is supposed to build the back-pressure needed to fool the o2 into thinking the 'cat's there. I would also get those holes patched when you can. I'm not saying that this is a solution to this current problem, but it may help it run more smoothly. I'll let the gurus comment here

[Festiv93]

Thanks everyone for all the help so far!:thumbs_up:

[blkfordsedan]

Having (or not having) a cat shouldn't make any difference on the fuel ratio. Even on a car with 2 sensors, the last sensor just monitors the efficiency of the cat. I have the rear sensors turned off my Mustang because the hi-flow aftermarket cats will still throw the CEL. The sensors respond to oxygen, not back pressure......however, an exhaust leak near or around the O2 sensor can draw or suck outside air into the exhaust pipe. This extra introduced oxygen can really throw the O2 reading off, and hence the fuel mixture as a result.

basically, you don't need the cat, but you can't have any leaks close to the O2 sensor either.

[CrookedHalos]

You don't have a friend with a Festiva? It really sounds exactly like my MAF problem I had when I bought the car. I had to drive home slow, very light on the throttle or if I pressed on the gas too hard it felt like it will stall. If you know anyone with a Festiva around you, test out their MAF sensor and see if that helps. The guy I bought it from thought it was timing and all that also. Keep your MAF sensor connected and prop the little door inside it open. Rev the car abit. If it feels better that's the culprit.

[Festiv93]

yes thats exactly what mine does. If im not light on the throttle it will fall on its face. Looks like the MAF sensor will be my starting point, its also the easiest to get to lol thanks. I will let everyone know if that fixes it

[Pu241]

There's only one o2 sensor. I've heard that you can use a 12" glass pack in replacement of the 'cat, which is supposed to build the back-pressure needed to fool the o2 into thinking the 'cat's there.

Uh, me thinks who ever told you that was "jiving" you!
Back pressure or will not change the chemical composition of the exhaust to an extent that an O2 sensor can be fooled.
As a matter of fact the sensor must work for the engine to run in closed loop mode.
Other wise it runs in warm-up mode, and your MPG is reduced, greatly.

[FestYboy]

^ +1

a load based stutter should be addressed from the ignition system first. if the VAF was an issue, it wouldn't matter what the load was because it only measures the volume/mass of air moving into the engine, so the faster the engine spins, the more the the vane moves. jumping on the throttle will momentarily make the vane move more than usual for the given engine speed, but your stutter will cause the vane to close due to the engine falling on its face and stalling, so that can be rulled out.

again, get a water spritz bottle and test the coil/cap for arcing.