Surge problem
Thread Starter
|
New User
Joined: Aug 2005
Posts: 14
Likes: 0
Surge problem
I've got a 93 with 3.0. Upon starting in this lovely cold MI weather the motor surges until it warms(apprx 3 to 5 mins). I've done a complete tune up, ie plugs, wires, rotor, distrib cap, O2 sensor, egr valve, fuel filter, K&N air filter, and have checked best I can all vacuum hoses. It was doing it in the warm weather also but only for a matter of seconds then would smooth out. When I try to drive off before the surging ends it will stall and act like the engine has been flooded when trying to restart. PLZ any suggestions. apprx 140k on vehicle
Posting Guru
Joined: Jul 2004
Posts: 2,416
Likes: 1
From: Mitchell, SD
That sounds like your IAC (Idle Air Control) valve is dirty or warn out. You did not mention replacing or cleaning it so I bet that is part of your problem.
Also I would not run a K&N filter. The oils from it coat the MAF causing drivability and fuel economy issues. I would clean the MAF wire with some Electrical Contact cleaner. That should help also.
Any other questions, an we will be here for you.
Also I would not run a K&N filter. The oils from it coat the MAF causing drivability and fuel economy issues. I would clean the MAF wire with some Electrical Contact cleaner. That should help also.
Any other questions, an we will be here for you.
Posting Guru
Joined: Jul 2004
Posts: 2,416
Likes: 1
From: Mitchell, SD
The MAF is that big metalic thing right next to the air filter box (It is part of the intake hose). If you open your filter box and look down the tube you will see a wire running up and down in the metal part of the intake.
The IAC is located right after the throttle body on the intake manifold. It is a cylinder looking thing with a wire plug attached. You have a 50% chance of cleaning it, so it is worth a try. If that does not work, you have to replace, but most auto parts stores do carry them.
The IAC is located right after the throttle body on the intake manifold. It is a cylinder looking thing with a wire plug attached. You have a 50% chance of cleaning it, so it is worth a try. If that does not work, you have to replace, but most auto parts stores do carry them.
Fleet Mechanic
Joined: Mar 2004
Posts: 1,529
Likes: 35
From: Kansas
Originally Posted by 93nighthawk
The MAF is that big metalic thing right next to the air filter box (It is part of the intake hose). If you open your filter box and look down the tube you will see a wire running up and down in the metal part of the intake.
The IAC is located right after the throttle body on the intake manifold. It is a cylinder looking thing with a wire plug attached. You have a 50% chance of cleaning it, so it is worth a try. If that does not work, you have to replace, but most auto parts stores do carry them.
The IAC is located right after the throttle body on the intake manifold. It is a cylinder looking thing with a wire plug attached. You have a 50% chance of cleaning it, so it is worth a try. If that does not work, you have to replace, but most auto parts stores do carry them.
Post Fiend
Joined: Apr 2005
Posts: 5,720
Likes: 5
From: Washington state
not a complete tuneup unless the codes are read, KOEO, KOER and cylinder balance tests are ran on an OBDI powertrain. ascan tool will tell even more about the ECU/PCM sensor operating parameters of your vehicle.
please read codes, run tests and post back with results
please read codes, run tests and post back with results
Thread Starter
|
New User
Joined: Aug 2005
Posts: 14
Likes: 0
Trending Topics
Former ******
Joined: Nov 2004
Posts: 4,901
Likes: 2
From: Salt Lake City, Utah
As for improved mileage, switching to a K&N will not improve mileage, except as opposed to a F**m or a plugged filter. OEMs have the best airflow vs. filtering efficiency. If you replace the filter with a K&N, the engine will detect the increased airflow, and increase fuel accordingly, or the driver will naturally decrease throttle, which will yeild in the same performance and the same fuel consumption. So it is nearly impossible to improve fuel economy by installing a higher flow filter. However, it is not only possible, but probably that plugged filters hurt mileage. This is because the air will pull to as much as a ten lb. vacuum, which causes less air to be taken in per stroke, at which point, performace suffers. At the same time, the outside wind resistance hasn't changed and the intake stops inducting. The combined effect will harm economy. Namely, you will find yourself putting on more throttle, which in turn means the computer anticipates rapid acceleration. This means that it runs slightly rich, hopeing that the engine will catch up and equalize the mixture.
Use just regular air filters, a new filter will get you the same gains as the K&N.
Use just regular air filters, a new filter will get you the same gains as the K&N.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Post Fiend
Joined: Oct 2005
Posts: 5,242
Likes: 0
From: Kiev, Ukraine
8000 rpm! Or may be 9000! It is possible if you replace camshaft by special one, but... valve springs are not disigned for it, and you can find retainer flying away..., valve dropping in cylinder and all related with this event problems.... So I had to install little additional springs inside the original ones. So I have dual valve springs... Else there is no reason to use high flow racing air filters, dual exhaust...
Former ******
Joined: Nov 2004
Posts: 4,901
Likes: 2
From: Salt Lake City, Utah
Look at the airflow ratings on a stock filter. It is rated in CFM. Now, take your 3.0 for example. Multiply its displacement by the maximum RPM it can do (redline) this should be 5500 or 6000. Lets say 6000. Now diveide the result by half (3.0 X 6000 = 18,000 / 2 = 9000) So this engine can move aa theoretical 9000 LPM. Now, there is always inneficiencies at high RPMs, often by as much as 10%. So reduce this value by 10% (9000 x .9 = 8100) So we would get closer to 8100 LPM. Now we still have to convert LPM into CFM. So we the answer I come up with is 286.0488 CFM. Now, I think the K&N filter for the Aerostar is rated to 980 CFM. For the Aerostar to come even close to useing the potential of this filter, it would have to turn over at 15,000 RPM. Now, the OEM filter is rated to about 880 CFM. Even the fram is rated much higher than the engines realistic potential. The best thing that can be done for the Aerostar's airflow is to remove the air horn from the intake of the airbox. It is very small and limits maximum airflow to about 250 CFM.
All of this doesn't even say the bad stuff about K&N filters. All say I if you want me to go on.
All of this doesn't even say the bad stuff about K&N filters. All say I if you want me to go on.
Post Fiend
Joined: Oct 2005
Posts: 5,242
Likes: 0
From: Kiev, Ukraine
Khantyranitar! Have you seen valve timing diagram of 3.0 EFI? Looking at these diagrams we can understand how mach air flow throught a manyfold. It would be interesting to see a torq. and power diagrams too. If you have it, please post these images.
I have a modified camshaft, so my diagrams are different.
It seem to me that engine perfomance will not be optimal at 8000 RPM with original camshaft...
And the other point: exhaust limits engine power too, and when you try to increase engine perfomance it is really difficult to find the limiting factor.
Averege power of 3L DOHC motor is 200 (+- 10) HP, engine of Aero is OHV with 1 camshaft, so according my experience its max. power is not more 185-190 HP...
I have a modified camshaft, so my diagrams are different.
It seem to me that engine perfomance will not be optimal at 8000 RPM with original camshaft...
And the other point: exhaust limits engine power too, and when you try to increase engine perfomance it is really difficult to find the limiting factor.
Averege power of 3L DOHC motor is 200 (+- 10) HP, engine of Aero is OHV with 1 camshaft, so according my experience its max. power is not more 185-190 HP...
Elder User
Joined: Aug 2005
Posts: 996
Likes: 0
When I drive the 4.0 aero, the computer says 20 ish mpg. when my wife drives it, it gets 13, she is not a bad driver but technique matters, I actually drive faster.
It is a well established fact that when we install economy improvers, we subtly change driving habits. I believe this is where the mileage improvements come from with k&n filters. The computer simply compensates. It does not matter whether the filter or the throttle valve meters the air fuel to the engine. the computer compensates.
Ken
It is a well established fact that when we install economy improvers, we subtly change driving habits. I believe this is where the mileage improvements come from with k&n filters. The computer simply compensates. It does not matter whether the filter or the throttle valve meters the air fuel to the engine. the computer compensates.
Ken