BimmerJeeper

No Start Checklist

NOT CRANKING

1. Check battery voltage (12V)
2. Clean/tighten battery terminals. (Loose and/or corroded?)
3. Check Gear Selector (Make sure you're in Park)
4. Neutral Safety Switch (Try to start in Neutral, not Park)
5. Check grounds
6. Is starter getting power? (With the key in the ON position, check for approximately full battery voltage at the starter.)
7. Starter (Hit with hammer)
8. Starter (Jump with screwdriver. Connect 2 highest bolts. 1 small. 1 big)
9. Starter Motor Fuse #19 (Kick panel: Fuse #19 (10A red))
10. Starter Motor Fuse #10 (Engine Bay Fuse Box (PDC). Fuse #10. See diagrams)
11. Starter Motor Relay (Engine Bay Fuse Box (PDC). “Cube” relay at end of fusebox)
12. Ignition Switch (Turn on the blower motor fan on for your heater with your key in the 'run' position. Turn the key to the 'start' position... the fan should turn off as it trys to crank over, indicating a good ignition switch.)

CRANKS, BUT NO START

1. Is gas tank empty?
2. Fuel pressure. 48psi (+/- 5psi). Listen for Fuel Pump?
3. Fuel pump relay (Engine Bay Fuse Box (PDC). Fuse #22. See diagrams)
4. Ignition fuse (Kick panel: Fuse #11 (20A))
5. Check for spark.
6. Bad spark plugs?
7. Bad Distributor, Cap, Wires?
8. Crank Position Sensor (CPS)
9. Bad coil pack?
10. Bad ECU?
11. Testing the TPS
12. IAC, TPS, CPK, MAP Failure Symptoms

Engine Bay Fuse Box (PDC)


Kick Panel Fusebox


Misc reading:
Replaced Crank Sensor, Pickup Coil, Spark Plugs, Wires, and Distributor Cap; unit still won’t start.

https://www.cherokeeforum.com/f2/non...writeup-71401/
https://www.cherokeeforum.com/f2/lon...8/#post2182489
http://www.jeepforum.com/forum/f11/p...l#post10006643
http://www.jeepforum.com/forum/f11/p...9/#post7683626
http://www.naxja.org/forum/showthread.php?t=101119
http://www.jeepforum.com/forum/f11/b.../#post14517948

holycaveman

Alright I am tired but I will try to do this. LOL

If it cranks over fine, then go to next post.

Doesn't crank.

Check gear position. A miss adjusted linkage can cause a no start issure very easily.
Check battery. NOT just a voltage check. A load check. You can read 12 volts and your battery can still be shot.
Make certain terminals are clean

IF your battery is good. Check connections to the starter.

check for clicking at the starter. IF it clicks then your sylenoid is good Could be starter.

What I do is jump the starter, this bypasses everything. if it cranks, the starter is good, if it does not, its bad.

holycaveman

It cranks over but no start.

First thing is to find out if you have fuel, and spark.

Fuel:
Listen for fuel pump.

NO pump
Crank position sensor
fuel pump
relays

If you hear the pump check for pressure at the fuel rail valve.
IF it just dribbles
Bad crank sensor and or relays
Bad fuel pump
Bad fuel line or filter
IF it sprays good
Poor fuel(a little) into intake
IF it fires
Could be a bad cam sensor
Fuel injectors(rare)
IF it does not fire
you have no spark
Plugs bad
coil bad
crank sensor bad
computer bad
distributer/cap/or wires bad


There is a lot more. But these are basics that may help So I just went with the common problems/symptoms

BimmerJeeper

Which of these 3 bolts are used to jump the starter?

BimmerJeeper

Bad crank sensor and or relays

Can you be specific about which relays you mean, and where they are?

holycaveman

The best way is to run 12 volts directly to the large stud closest to the starter. Positive on the stud, negative on the starter housing.

This bypasses everything and tests the starter directly.

Some just arch the two large studs together. But sometimes they can be the cause with a bad contact, or bad wire.

arching the small stud to the upper large stud operates the starter just like hitting the key, it engages the sylenoid to turn the starter over.

The relays are the automatic shut down relay, and the fuel pump relay.

Lostfisher1

Beemer are you a boy scout or something, be prepared. Its been a month and you have over 300 posts.

cdhebert

The top two.

Jurnymn

I had that same prob about a year ago. Replaced most of that. It came down to the last thing I haven't replaced was the computer and the battery. I replaced the battery and it has been fine since. I know it doesn't make sense, but I unplugged the computer, plugged it back in, bought a new battery and it's been fine.

BimmerJeeper

Then the bottom 3rd bolt sends the current to the starter below?

BimmerJeeper

I see them in the engine bay fuse box.
At 14 years and 125k miles, I am just going to replace all 4 large relays before they die.
(Starter, fuel pump, fan, shut down) Bad idea?

BimmerJeeper

I have updated the master checklist above. Can someone please verify?