4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

Question about a "surge" on the air intake...

Thread Tools
 
Search this Thread
 
  #1  
Old 03-18-2008
WowMike2001's Avatar
Member
Thread Starter
Join Date: Oct 2007
Location: Stevenson, WA
Posts: 2,583
Likes: 0
Received 3 Likes on 3 Posts
Question about a "surge" on the air intake...

Not sure if its common or whatnot, it isn't too bothering but I need to know if anyone has any issues on when your going a steady speed, say 25mph in town.. and every now and then you can hear the intake suck in a little more air then normal and sort of pulses for just a second then goes back to normal. The engine RPM's pulse with the intake rising as well, I can feel it pull forward ever so slightly...

I have a K&N FIPK II CAI installed on my truck.. I cleaned the MAF sensor just to see if it would do anything, still pulses ever so slightly from time to time. Not worried about it that much, just seems odd.. wouldnt mind having an engine that runs 100%, but let me know if you have any ideas!
 
  #2  
Old 03-18-2008
Fx4wannabe01's Avatar
RF Veteran
iTrader: (23)
Join Date: May 2005
Location: Boring, Oregon
Posts: 21,721
Likes: 0
Received 10 Likes on 10 Posts
Mine does the same thing......sorta sucks in more air for a few seconds, them goes back to normal. I'm cuious as to the reason as well.
 
  #3  
Old 03-18-2008
WowMike2001's Avatar
Member
Thread Starter
Join Date: Oct 2007
Location: Stevenson, WA
Posts: 2,583
Likes: 0
Received 3 Likes on 3 Posts
I read up a teeny bit.. searched and dug for a very broad range of searching, Someone recommended something about changing the fuel filter.. I might go ahead and do that down the line perhaps.

All the way up to it being a surge in the air compressor, supposedly somewhat "normal" in certain circumstances.


Any other recommendations or things to take a peek at may help as well too :-)
 
  #4  
Old 03-18-2008
V8 Level II's Avatar
RF Veteran
iTrader: (4)
Join Date: Nov 2004
Location: Michigan
Posts: 7,910
Likes: 0
Received 23 Likes on 20 Posts
The A/C compressor clutch may be cycling normally. Depending on the ambient temperature, the compressor can run in every HVAC mode except OFF, FLOOR ONLY and VENT ONLY. Try switching the control to OFF and see if it stops surging.

Another idea - In addition to its idle function, the IAC valve is also active during cruise conditions. The PCM prepositions the IAC partially open to reduce the high vacuum that occurs during decelerations and manual gear changes. (Sudden vacuum increases cause condensed fuel in the intake runners/plenum to flash to vapor which may cause hydrocarbon spikes on the emission test.) You may be hearing the normal function of the IAC that is just more noticeable with the unsilenced FIPK. Or the IAC could be sticking slightly before jumping to the correct position.
 
  #5  
Old 03-18-2008
WowMike2001's Avatar
Member
Thread Starter
Join Date: Oct 2007
Location: Stevenson, WA
Posts: 2,583
Likes: 0
Received 3 Likes on 3 Posts
Hmm, good information indeed... Its not very bothering at all liek I mentioned above.. I'm jsut more curious as to what it is... thanks for a heads up on that, I can test it out switching the compressor to off for a bit.


Thanks rwenzing!!
 
  #6  
Old 03-18-2008
Fx4wannabe01's Avatar
RF Veteran
iTrader: (23)
Join Date: May 2005
Location: Boring, Oregon
Posts: 21,721
Likes: 0
Received 10 Likes on 10 Posts
Holy crap! I completely forgot about the AC clutch...duh. I knew that...but forgot. Bob, as always, your'e the best.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
deddhead
SOHC - 2.3L & 2.5L Lima Engines
0
04-07-2011 07:30 PM
RangerRunner96
2.9L & 3.0L V6 Tech
5
08-29-2008 01:01 PM
rangerbert
4.0L OHV & SOHC V6 Tech
8
06-05-2008 05:45 PM
vypr97
Ranger-Forums Office
2
04-30-2008 07:51 PM
motoman1980
General Technical & Electrical
1
12-02-2007 03:00 PM



Quick Reply: Question about a "surge" on the air intake...



All times are GMT -6. The time now is 04:16 AM.