Applying something learned on this Forum....

[DOCTORBILL]

I have learned quite a lot reading this forum.

For instance:

I now know that in some systems the fuel pump "pressurizes" the fuel supply
tubing (system) - doesn't JUST deliver fuel.

I have a 1991 Jeep Cherokee that has always needed to be cranked for maybe
20 to 30 seconds before it starts. This has been the 'norm' for 7 - 8 years.
Been waiting fo rthe starter motor to wear out......

That is to say, hard to start (seemingly).

Well, now that I have learned about the Fuel Pressure regulator thru discussions
with you's guys (especially Blake - 'DieInterim"), I know that the fuel system needs
to develop some level of pressure to work properly.

This Jeep has the good ol' tractor straight six fuel injected 4 liter engine and should be
good for 300,000 if taken care of (oil and filter changes!).

So just for the grins of it, one day several weeks ago, I turned the key to the 'on
position' and left it there for about 20 - 30 seconds so the fuel pump had time to build up
the pressure BEFORE using the starter motor to uselessly crank the engine.

BAM! Whammo! Bingo!
It started right up!
Very unusual for this car.
We always sat there cranking away before it would start!

Lesson learned.......

DoctorBill (always learning something new!)

[MT-2500]

10-4
That is what they call prime up. Works every time.
In the good Old days we just dumped a little gas in the carb.
But with new cars there is always new ways.
MT

[DOCTORBILL]

On the fuel rail is a schraeder valve (bicycle), screw your gauge into that.

OK - I need a picture, I think.... Ich weis nicht was gibt...."Fuel rail"?
"schraeder valve" - no idea what that would look like.

As I said, I wait maybe 20 seconds - I'll try 5 or 6 and see. How long would it take for
the pressure to build up.?

This has gone on for years! if the key switch was bad, wouldn't it get worse over that
time?

This Jeep engine (should I go over to the Jeep Forum?) looks quite complex to me.
The fuel injection area is boxy and complex - for a novice like me anyway.

I may fall back to the taking of pictures to have you point out this rail and valve.

Then again - I have my plate full with the Geo Metro I have been waiting to work
on once the weather lifts.

But - if anybody has an engine they have to crank a long time - try what is working
for me now....

DoctorBill

[DOCTORBILL]

All right....I just went outside in my pajamas and used my old Polaroid PDC 700 (0.8 MP)
digital camera and took two pics of my 1991 Jeep engine.

First image of engine compartment. The RED HOSES on the left are that split electronic
wire insulation to prevent cross firing. WORKS!



This second image is a close up of what I am supposing is that "schrader valve, the same valve
used in bicycle tires" that you wrote about ---- Yes?

BTW - where would I tap in to put an Oil Pressure Gauge since my electric gauge crapped out
and it costs one of my testicles to get it replaced...? I bought a gauge with the old TUBE - i.e. mechanical.



Let me know, please.
Also, is that canister-thing to the left of what my yellow arrow is pointing at the Fuel
Pressure Regulator?

DoctorBill

PS - Isn't that one BEAUTIFUL old straight six 4.0 liter "tractor-like" engine!?
Just turned over 200,000 miles and going like crazy!
Just 2X what my Geo Metro 3 cylinder in-line is - Except 4X bigger!..20 mpg Highway.
This is a 5 speed manual with a truck clutch. One of Jeep's most dependable vehicles....

[Crvett69]

yes, unscrew that small cap and hook a fuel presure gauge to that, and yes the thing to the left is your pressure regulator. on your oil pressure gauge, its usually the oil pressure sending unit on the engine that goes bad, they usually don't cost more than $30. unless you buy it from dealer then its a lot higher. find where it is on the engine, have some osit in car and watch gauge. with ignition on take wire off the sending unit on engine and touch it to ground, if gauge goes up its a bad sending unit. if not its the gauge. if the gause is bad just unscrew the sending unit and hook your manual line up there

[DOCTORBILL]

"....the oil pressure sending unit ......find where it is on the engine....

Yes - that is the thing! Where the Hell is it!?

If it has a "wire" going to it, then that wire will be coming out of the wiring harness
"somewhere" and finding that wire is the rub.....

If it were of the type I want to install, there would be a metal or plastic pressure
tube to follow out of the firewall.

Just a wire can be ANYWHERE!

BTW - a Chrysler repair shop told me the gauge is dead and the sender is good.
They said to fix the gauge would cost about $1,400 as they would have to replace
the ENTIRE gauge display in the dashboard! It is not repairable........lol actually nlol

So I am replacing the gauge with the old fashioned reliable mechanical type and
will put it where the clock would be if whoever had bought this car new had purchased
a clock 'option.'
EVERYTHING on Jeeps is an 'option' !!!

EVERY SINGLE THING..!

DoctorBill

[Crvett69]

its usually on the side of the block fairly close to the oil filter. if you do find it try the wire to ground test, if gauge is dead not gonna lose anything and we all know shops are NEVER wrong