Another Engine Surging thread JRICHKER?

Do you have a Cold Air Intake other than the stock airbox and flat panel filter?

Clocking the MAF would have been my next guess. Can you pin down some of the conditions that seem to happen before the surge happens? Things like outside air temp, coolant temp, slowing to a stop, etc.

Is your timing set with a timing light?
Your problem will probably be more prevelent in stop and go driving. With that in mind, try clocking the MAF in 45* increments to see if that makes a difference.


Recommended procedure for cleaning the IAC/IAB:
Conventional cleaning methods like throttle body cleaner aren’t very effective. The best method is a soak type cleaner used for carburetors. If you are into fixing motorcycles, jet skis, snowmobiles or anything else with a small carburetor, you probably have used the one gallon soak cleaners like Gunk or Berryman. One of the two should be available at your local auto parts store for $22-$29. Take the solenoid off the body and set it aside: the carb cleaner will damages some types of plastic parts. Soak the metal body in the carb cleaner overnight. There is a basket to set the parts in while they are soaking. When you finish soaking overnight, twist the stem of the IAB/IAC that sticks out while the blocker valve is seated. This removes any leftover deposits from the blocker valve seat. Rinse the part off with water and blow it dry with compressed air. The IAC/IAB should seal up nicely now. Once it has dried, try blowing through the bottom hole and it should block the air flow. Reassemble and reinstall to check it out.

Gunk Dip type carb & parts soaker:



Setting the base idle speed:
First of all, the idle needs to be adjusted to where the speed is at or below 600 RPM with the IAC disconnected. Then the electrical signal through the IAC can vary the airflow through it under computer control. Remember that the IAC can only add air to increase the base idle speed set by the mechanical adjustment. The 600 RPM base idle speed is what you have after the mechanical adjustment. The IAC increases that speed by supplying more air under computer control to raise the RPM’s to 650-725 RPM’s

Remember that changing the mechanical idle speed adjustment changes the TPS setting too.

This isn't the method Ford uses, but it does work. Do not attempt to set the idle speed until you have fixed all the codes and are sure that there are no vacuum leaks.

Disconnect the battery negative terminal and turn the headlights on. Leave the battery negative terminal disconnected for 5 minutes or so. Then turn the headlights off and reconnect the battery. This erases the computer settings that may affect idle performance.

Warm the engine up to operating temperature, place the transmission in neutral, and set the parking brake. Turn off lights, A/C, all unnecessary electrical loads. Disconnect the IAC electrical connector. Remove the SPOUT plug. This will lock the ignition timing so that the computer won't change the spark advance, which changes the idle speed. Note the engine RPM: use the mechanical adjustment screw under the throttle body to raise or lower the RPM until you get the 600 RPM mark +/- 25 RPM. Changing the mechanical adjustment changes the TPS, so you will need to set it.

When you are satisfied with the results, turn off the engine, and re-install the SPOUT and reconnect the IAC. The engine should idle with the range of 650-750 RPM without the A/C on or extra electrical loads.

Sounds like the timing was set wit the correct tool. I will assume that you removed the SPOUT when setting the timing and put it back in when you finished.

Airflow is a funny thing with C&L MAFs, sometimes they work perfectly and other times they have problems. Clocking the MAF is a cheap and simple test trick that will help eliminate the MAF as a possible problem source.

It sounds Ike you are having the same problem I did. One of the main causes was the ignition control module. Check out my blog post about it...http://www.nerddawg.com/2011/06/first-set-of-problems.html?m=1 I was getting an 18, but you may be hitting this right at the start and it hasn't thrown a code yet.

That combined with cleaning the throttle body fixed my problem.

bdazzgt said:

No, I have the C&L mass airmeter hooked to the factory airbox. I tried reclocking the mass air meter, but its hard to know if I have fixed the problem due to it not surging all the time.

Click to expand...

Does your C&L 76mm MAF have the Blue (#102) calibration tube?

You can get your ignition control module tested at autozone prior to buying one. It is worth a shot.

Check your vacuum lines and make sure the line to the carbon canister is capped and not leaking. The code 85 indicates that the canister purge solenoid has been removed, so the leftover plumbing poses a possibility for vacuum leaks.