Does anyone have a vacuum diagram for a 1999 jeep TJ wrangler 2.5L
the service manual OEM 120 pages, said this, did VECI fall off?
VACUUM SCHEMATICS
A vacuum schematic for emission related items can
be found on the Vehicle Emission Control Informa-
tion (VECI) label. For label location, refer to Vehicle
Emission Control Information (VECI) Label" << federal laws here EPA.
engine starts (sure) but does it have FULL POWER hot and cold????????????
throttle cable jammed?
is it automatic tranny>? and Kick down cable jammed?
got cruise. and cruise to TB cable jammed.
scans show this:
"P1299 Vacuum Leak Found (IAC Fully
Seated)
MAP Sensor signal does not correlate to Throttle Position
Sensor signal. Possible vacuum leak!"
FAST IDLE HAS MEANY CAUSES!
THE Primary case is the IAC fails or vacuum leaks cause the IAC to go out of control. IAC is bolted to the TB. and is weak, then.
I have the service manual, so can be exacting
as you may know this jeep uses MAP Sensors fuel then engine.
called Speed Density system. jeep (as in NO MAF sensor)
that means any vacuum leak, cause fast RPM even your right foot does.
the 2.5 is cut down 4.0L:
and is MPI 4 injectors injecting it.
we can pinch all vacuum lines, (not PCV) and see if RPM hot drops from 2k to 800 rpm,. bingo that line leaks if it drops RPM large.
easy no? ,just pinch a line. or pull the end point and cork it, up.
the car is 1999 and all 99 cars USA (is it) have OBD2 port. why not just scan the PCM first.? see errors called DTC. and can really help cut down time. and buying useless parts not needed at all.
I owned for years a 1999 cherokee, 4.0L near same drive line. 5sp,m/t box.
here are some very very common caused, seen on all ;my jeeps back to 1988.
this is not guess, it is all jeeps fail here. every one,owned long enough and not serviced correctly
THE IAC is simply clogged up., so clean it? all; mine loved to clog until my newer jeeps are TBW,throttle by wire. no IAC , now, gone.
The the Throttle body TV throttle valve plate is gunked up and sticking open
again, clean it. (PULL TB off)
that is 2 thing things and to be frank , vast places go get vacuum leaks
even old cracked injector cushion seals( at base) sucking air.
we use a smoke machine on the hard nut cases. just like EVAP side.
more, Brake booster leaks, called a huge vacuum leaks
I bet EVAP hoses do not race the engine ever.
map vac hose cracked
egr hoses cracked. vac.
HVAC dash heater controls vac hose cracked and sucking air./
canister evap purge valve hose cracked, sucking air
it has a distributor vacuum advance hose. plug them to see if they leak.
the map sensor quote SM.
"INSTALLATION
(1) Install rubber L-shaped fitting to MAP sensor.
(2) Position sensor to throttle body while guiding
rubber fitting over throttle body vacuum nipple.
(3) Install MAP sensor mounting bolts (screws).
Tighten screws to 3 N·m (25 in. lbs.) torque.
(4) Install air cleaner intake tube"
see that word rubber there, what if that leaks air.
the under hood HVAC parts there have vacuum tank to hold vacuum in reserve and it too can leak air .
I have cured vast vacuum leaks. on engines.
nature abhors a vacuum (on earth)
the end point sucks air. (like diaphragm devices and HVAC lots)
to see all vacuum things in my OEM SM
I had t type F3 100 times to find them all. find.F3 command.
PDF reader.
no single diagram is there in the book, , its on the VECI lable on car.
look under hood and up and under hood yet?
the PCM can go to limp home
and doing so can force the IAC to dead, OFF LINE,
so not scanning the PCM first is really bad idea. knowing just that.
good luck, !
7/11/2023 2:16:21 PM •
Jeep Cars &...
•
Answered
on Jul 11, 2023
•
31 views