Re: 98 caravan 3.3 poor gas mileage

On Oct 15, 7:11 pm, jroma...@xxxxxxxxxxx wrote:
On Oct 14, 12:32 pm, jroma...@xxxxxxxxxxx wrote:





On Oct 14, 9:38 am, philthy <dbri...@xxxxxxx> wrote:

did the tire size change?/ if it died was the pinion factor also changed

jroma...@xxxxxxxxxxx wrote:
On Oct 13, 11:58 am, "Mike" <m...@xxxxxxxxxxxx> wrote:
"Gyzmologist" <y...@xxxxxxxxx> wrote in message

news:fq5Qi.21$xP1.8@xxxxxxxxxxxxxxx

Exhaust gas is inert.

Correct

Adding it to the intake stream increases the

charge density and thus the amount of gas that will be expanded by
ignition.

Wrong. It decreases charge density. Remember that it is an inert gas so it
dilutes the A/F mixture which reduces peak combustion chamber temps to
reduce the formation of NOx.

The results will vary with different types of engine control

systems.

Works about the same on all of them.

One possibility is a drop in MPG while cruising.

The OP stated that the EGR valve was stuck CLOSED. If it was stuck open it
may cause a drop in mileage.

Mike wrote:
"Gyzmologist" <y...@xxxxxxxxx> wrote in message
news:9OwOi.1246$DP1.1131@xxxxxxxxxxxxxxx
Check the EGR valve to see if it is stuck closed.

How would an EGR valve stuck closed cause a reducton in fuel mileage
???

jroma...@xxxxxxxxxxx wrote:
Asking for advice
1998 Caravan SE 3.3 163K
Starting back in May my mileage dropped from 18.5mpg in city driving
since new to 16.
Just thought it was the hot summer and using the air conditioner all
the time.
Now with cooler weather the mpg has stayed at 16mpg.
I'm not getting any check engine/service engine so lights.
I've replaced the air filter ,plugs and wires with dealer parts no
change.
Brakes are not dragging. Tires@32lbs.
Transmission is not slipping engine revs 2000rpm@60mph since new.
Had it to the local service station and they checked for obdII codes
and none found told me that its going into closed loop operation and
the O2 sensor is switching.

Anyone have any ideas what may be wrong??

--
Gyz

Everyone thinks they know how to drive.
Everyone thinks they are good drivers.- Hide quoted text -

- Show quoted text -

I have you hesitation/stalling of engine at idle and no pinging of
engine at speed both good indications of the egr working correctly.
I am not getting any check engine lights.
I will be replacing the front O2 sensor this week.
will let you know if that fixes it.- Hide quoted text -

- Show quoted text -

no tires 4 yrs. old- Hide quoted text -

- Show quoted text -

installed new front O2 sensor this morning
will let you'll know what the MPG is after I run thru a tank full- Hide quoted text -

- Show quoted text -

couldn't wait to use a full tank of gas
170.4 miles and 9.759 gallons of gas = 17.46 MPG
up about 1.5 mpg but still lower then past average of 18.5
I'll continue to monitor the mpg and see if it increases


.

Relevant Pages

  • Re: Car shuts off
    ... He warned me that it would not run below 1/4 tank of gas. ... Over time I replaced everything in that fuel system except the gas tank to ... I had two cars in the 80s that they died at the certain engine temp. ... It probably would say O2 sensor or fuel mixture lean... ...
    (alt.auto.mercedes)
  • Re: Can you get fuel sensors to detect the right kind of fuel for a car?
    ... I think it would be a good idea to put a sensor in the tank that would ... stop him driving off and wrecking his engine. ...
    (sci.electronics.basics)
  • Re: Chrysler Suicide Watch 37: No Lease on Life
    ... I'm not impressed with the hybrids at all. ... I have a '94 Eclipse 2.0L turbo that is putting out 240HP and gets me an average of 33 MPG per tank. ... Ever wonder why hybrids cannot be recharged using electric power, but only through the engine? ...
    (rec.autos.makers.chrysler)
  • Re: egr system on toyota
    ... EGR valve, throttle body ports, etc). ... The engine coolant temp sensor does not affect P0125. ... or short in the sensor circuit, or an exhaust leak that is ...
    (alt.autos.toyota)
  • Re: egr system on toyota
    ... EGR valve, throttle body ports, etc). ... The engine coolant temp sensor does not affect P0125. ... check the EGR vacuum modulator: ...
    (alt.autos.toyota)
Loading