try a new mopar i.a.c motor that should help your issue
sls5448@[EMAIL PROTECTED]
wrote:
> On Apr 14, 1:55 pm, Mike Romain <roma...@[EMAIL PROTECTED]
> wrote:
> > sls5...@[EMAIL PROTECTED]
wrote:
> > > On Apr 14, 12:13 pm, "Mike" <m...@[EMAIL PROTECTED]
> wrote:
> > >> <sls5...@[EMAIL PROTECTED]
> wrote in message
> >
> >
>>news:2a905b5d-e2ab-4848-bd6a-4c2f4d0962c7@[EMAIL PROTECTED]
> >
> > >>> I have a 93 grand cherokee with 200Kmiles. It idles smoothly and
runs
> > >>> ok but I cannot hold a steady rpm over 1000 RPM.It surges slightly
> > >>> over a 300 RPM range. I've replaced cap, rotor, wires, coil, and
> > >>> plugs. I've checked all the vac*** hoses for leaks. I even went as
far
> > >>> as to plug all the vacuun ****ts in the manifold and throttle body.
It
> > >>> still surged slightly.
> > >>> I removed the throttle body and cleaned it thoroughly, replaced
the
> > >>> TBI gasket. I've used seafoam in the gas tank (it ran really
crappy
> > >>> until I filled up again). Cylinder compression is good considering
> > >>> it's age (around 150psi max, 130 min).
> > >>> Fuel economy is less then I expect. In a relatively hilly area I
get
> > >>> around 11MPG in mixed (mostly city) driving. Overall drievability
is
> > >>> pretty good and power is good all the way to redline. This leads
me to
> > >>> believe I have enough fuel pressure.
> > >>> Any ideas?
> > >>> Thanks in advance!
> > >>> sls
> > >> Surging is usually a sign of running lean. I would check the
operation of
> > >> the O2 sensor(s) with a scan tool to make sure they are working
properly. To
> > >> do so you would need a scan tool that is capble of reading sensor
values. You
> > >> can also check O2 performance with a multimeter. It may be cheaper
just to
> > >> replace the O2 sensors from the start due to the high mileage on
the vehicle.
> >
> > >> I would check the fuel pressure as well just to rule that out as
a
> > >> possibility. The fuel pressure regulator increases fuel pressure
under power
> > >> conditions so it could still be low at cruise.
> >
> > >> What engine do you have ? If you have a V8 they have a pan on
the bottom of
> > >> the intake that is prone to leaking, the only way to check it is to
remove the
> > >> intake.
> >
> > >> Also check your EGR valve for proper operation. If it opens too
far or at
> > >> the wrong time that may cause a surge also.- Hide quoted text -
> >
> > >> - Show quoted text -
> >
> > > One more thing i didn't make clear in my original post. It's a
cycling
> > > surge. If I hold the throttle steady as if I was trying to hit
> > > 1500rpm, the engine will cycle from 1300 to 1600 RPM. Each cycle
(up-
> > > down-up) is about a second long. It does NOT do this at idle. RPM is
a
> > > steady 700 or so. Pretty much anythin above 1000 RPM will do the 300
> > > rpm cycle.
> >
> > > Interestingly enough, I replaced the throttle position sensor a few
> > > months ago. When I first started the vehicle, it idled at 1500 RPM.
It
> > > did the same 300RPM cycle even though the throttle was closed. Of
> > > course after the computer "got used to" the new TPS it idled
normally.
> > > It definitely appears to be RPM dependent.
> >
> > > Thanks!
> > > sls
> >
> > Usually the problem with the TPS is a bad connection, not a bad TPS.
> > You only fixed half the problem with the new TPS. I would get some
> > electronic spray contact cleaner and do out the plug and socket for
the
> > TPS first. The told us our TPS was dead in 1999, it was
> >
> > The other sensor's connections can also benefit from this clean. I
use
> > dielectric grease on the plug's sealing skirt to help keep them clean.
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 'New' frame in the works for '08. Some Canadian Bush Trip and Build
> > Photos:http://mikeromainjeeptrips.shutterfly.com-
Hide quoted text -
> >
> > - Show quoted text -
>
> Thanks for the feedback.
> The problem occured before I changed the TPS (one of the parts I threw
> at the problem)
> I actually did clean all the sensor connectors with radioshack contact
> cleaner (IAC, TPS, MAP) I also cleaned the washer and coolant
> reservoir sensors but they still show up bad at the most embarassing
> times on the VIC. :-)
|
