[deniz]

Hi all-
I can't figure this one out:
I am experiencing a hesitation with my duratec. It only happens under heavy acceleration above 3000 or 3500 rpm and it feels just as if the engine is hitting the rev limiter, that is, it hesitates, then accelerates, then hesitates.
The car runs great otherwise. All maintenance is up to date.
Any ideas?

 

[diesel600]

Maybe your secondaries are not opening???

 

[deniz]

Yeah, since the problem is intermittent and happens around 3-3.5K rpm, i did wonder if the imrc was going bad. I'm gonna check that out. Any other ideas?

 

[NateNBeckie]

Your secondaries may also be gummed up. I am going to clean mine next weekend because they are pretty dirty at 70,000 miles. I would check that before I spent a boat load of money on a new IMRC.

 

[gruffybear]

What is the correct process for cleaning the secondaries? Do you have to remove the lower intake?

 

[NateNBeckie]

I couldn't tell you for sure, but it looks like the lower part of the intake that the butterflies are in could come off separately. It's hard to tell with the upper manifold on.

I am sure someone in here knows for sure because they've had it apart...

 

[deniz]

Update:
I checked the IMRC, it opens fine. Also, since the problem is intermittent, I doubt gummed up butterfly valves are to blame. Lastly, I had my codes pulled at Autozone--nada.
So I'm back where I started.

 

[AutumnLX]

I am having the same problem ... my intake is clean / imrc is functioning.. no codes listed. Driveablity is fine.


97 Duratec

 

[robwiljas]

I'm having the same exact problem with my 99 Duratec, exactly as Deniz described. It's driving me nuts. Any other ideas on what it could be?

 

[97jivvity]

had the same problem with my 97, when i changed something like the fuel filter or spark plugs it ran great for a week then exactly the same surging. My last thought was the fuel pressure regulator because if it sat for a while it would take a while to turn over if you didn't give it a chance to prime the system suggesting a leak, but then again it might be a seal or something in the pump. no misfires no codes just surges....

 

[robwiljas]

Well now my Taurus is throwing codes and I'm hoping they're related. About a week ago it threw P0171 "System Too Lean (Bank 1)". I reset to see if it came back and it didn't, but today it threw P1131 " Lack Of Heated Oxygen Sensor Bank 1 Sensor 1 Switches – Sensor Indicates Lean". So now I'm most likely looking at a bad MAF or O2 sensor, or atleast I hope that's all it is lol. I'm going to try and clean the MAF sensor tomorrow and see if it makes a difference.