fluttering/power loss...

[farmgirl]

I'm in need of some assistance, I've got a 90 Bronco II, 64,000 in this motor.

Had it in the shop 3 times, cant find whats wrong.

I can feel a flutter in the pedal, then the RPM's drop and no power.

It will start right back up, and do the same thing.

If it sits It runs fine......no rhyme or reason to it.

Had the TPS changed

???

thx

 

[CraigK]

farmgirl

This one I know. (I think.)

Had the same thing on my '87 BII 2.9L. As soon as it would warm up, this "cycling behavior" would start. Feels like gas is being slowly cut off, then it comes back on. The engine would cycle like this from about once per minute, to several times per minute (mine got worse with time). And when it would "flutter" (mine was more like a sputter), it would catch again when I de pressed down on the gas pedal. This sputtering pattern was worse under cruising and low load conditions, and would go away only when I was accelerating hard. Gas mileage eventually dropped to about 8 mpg, and it would not pass the MD state emissions inspection.

And there was NO indicated engine code problem!

So . . . I changed my:

- spark plugs

- distributor cap/rotor

- wires

- fuel filter

- fuel pressure regulator

- distributor

- TFI

- MAP

- IAC

- etc. etc. etc.

Drove me crazy.

Then one day I disconnected the O2 sensor. Not replaced it, not removed it - just pulled the connector off. (On my vehicle, it's located on the exhaust pipe on the passenger side, close to where the exhaust pipes from both sides of the engine join together.)

End of problem.

And the vehicle passed the state inspection with flying colors.

And gas mileage instantly increased to about 15 MPG.

Sometime in the future, I'll install a new O2 sensor, but the engine runs very well now.

Good Luck!

CraigK

 

[89Bronco58]

fuel pressure problem, check your pumps and filters

 

[89Bronco58]

wholy crap dude, i didnt even read your post untill after i replied (craig) my full size bronco is doing the EXACT same thing as yours was, i mean every thing you said is what i say to people, ill have to unplug my sensor and try it

 

[CraigK]

89Bronco58

I didn't mention in my previous post - while I had this probelm I also . . .

I made a special fitting so I could fit a pressure gauge to the Schraeder valve on the fuel manifold to check fuel pressure. It was A-OK. I also hooked up a vacuum gauge on the vacuum lines and taped the gauge to the hood so I could watch it while driving around. Not the problem either. There's more stuff I did, but I just can't remember it all. It got kinda personal - between me and the stupid sputtering motor.

I hope disconnecting your O2 sensor works for you.

CraigK

 

[89Bronco58]

lol yea

 

[farmgirl]

farmgirl
This one I know. (I think.)

Had the same thing on my '87 BII 2.9L. As soon as it would warm up, this "cycling behavior" would start. Feels like gas is being slowly cut off, then it comes back on. The engine would cycle like this from about once per minute, to several times per minute (mine got worse with time). And when it would "flutter" (mine was more like a sputter), it would catch again when I de pressed down on the gas pedal. This sputtering pattern was worse under cruising and low load conditions, and would go away only when I was accelerating hard. Gas mileage eventually dropped to about 8 mpg, and it would not pass the MD state emissions inspection.

And there was NO indicated engine code problem!

So . . . I changed my:

- spark plugs

- distributor cap/rotor

- wires

- fuel filter

- fuel pressure regulator

- distributor

- TFI

- MAP

- IAC

- etc. etc. etc.

Drove me crazy.

Then one day I disconnected the O2 sensor. Not replaced it, not removed it - just pulled the connector off. (On my vehicle, it's located on the exhaust pipe on the passenger side, close to where the exhaust pipes from both sides of the engine join together.)

End of problem.

And the vehicle passed the state inspection with flying colors.

And gas mileage instantly increased to about 15 MPG.

Sometime in the future, I'll install a new O2 sensor, but the engine runs very well now.

Good Luck!

CraigK

 

[farmgirl]

Good? Morning ereryone that gave me some insite on my issue. It is VERY frustrating, especialy when the ford dealers cant figure it out.

Craig, I did have plugs, ignition wire set, dis cap, dis rotor, fuel filter, air, bla bla changed.

Your discription sounds a lot like what I go through, I drive the LA freeways and I do feel like I'm gona pull my hair out when the "experts" cant fix it. Thats why I thought of the REAL experts so thanks!

I will try the O2 sensor.

Did your condition come and go like mine, at times I can go for days and no prob.

Sputter was my word until the MAN used flutter, I'm back to sputter because thats what it feels like in the pedal.

the thing that is so puzzeling to me and everyone else is that 10 min after the problem starts it stops and runs fine.

Thanks !!

Farmgirl

farmgirl
This one I know. (I think.)

Had the same thing on my '87 BII 2.9L. As soon as it would warm up, this "cycling behavior" would start. Feels like gas is being slowly cut off, then it comes back on. The engine would cycle like this from about once per minute, to several times per minute (mine got worse with time). And when it would "flutter" (mine was more like a sputter), it would catch again when I de pressed down on the gas pedal. This sputtering pattern was worse under cruising and low load conditions, and would go away only when I was accelerating hard. Gas mileage eventually dropped to about 8 mpg, and it would not pass the MD state emissions inspection.

And there was NO indicated engine code problem!

So . . . I changed my:

- spark plugs

- distributor cap/rotor

- wires

- fuel filter

- fuel pressure regulator

- distributor

- TFI

- MAP

- IAC

- etc. etc. etc.

Drove me crazy.

Then one day I disconnected the O2 sensor. Not replaced it, not removed it - just pulled the connector off. (On my vehicle, it's located on the exhaust pipe on the passenger side, close to where the exhaust pipes from both sides of the engine join together.)

End of problem.

And the vehicle passed the state inspection with flying colors.

And gas mileage instantly increased to about 15 MPG.

Sometime in the future, I'll install a new O2 sensor, but the engine runs very well now.

Good Luck!

CraigK

 

[CraigK]

"farmgirl" drives the LA freeways??? /emoticons/[email protected] 2x" width="20" height="20" />

Yes. When this problem first started, it was intermittent, sometimes disappearing for weeks, and much lower in intensity. With time, the condition grew progressively worse, until the vehicle was all but useless, both from the sputtering, and from the extremely poor gas mileage. (I have about 130,000 miles on an '87 BII!)

I'm anxious to see if disconnecting the O2 sensor works for farmgirl and 89Bronco58 as it did for me. Please report back to the forum when you do this. Being slimeballs, most dealerships wouldn't fix a problem like this the first time anyways, even if they knew how. They **** your blood$$$ for awhile first. Note that it might be illegal, especially in CA, for a dealership mechanic or other licensed mechanic to simply disconnect the O2 sensor, as this is interferring with a part of the emissions control system. It's probably best to try to do this yourself. Or better yet, find someone to do it for you. Took me about 5 minutes. Again, Good Luck!

CraigK