Starting issue: regardless of time of day, hot or cold, sometimes my jeep seems like it will turn over 100 times before it will start. other times it starts right up no problem on the first couple turns. I've notice if I start to crank it over, then stop, then try it again it fires right up. What are your thoughts as to the issue? I've recently replaced the plugs and wires on my last tune up about a month ago.I will be stopping by AutoZone on my way home to have them check the battery.

 

check fuel rail pressure.

 

What's a good pressure number I should see? I've replaced the pump n filter about 4 months ago if that matters any.

 

If you are getting fuel you may want to see if you are getting a good spark. I have no idea what year your jeep is since you didn't say. But, if you have a single coil or if you have a newer jeep and have the coil packs?? If you have spark also check you CPS.

 

make sure all wires connecting your starter are connected and fast ---take it off put it back on ,make sure you have good case ground & the post connecting solenoid to motor are tight!!!!!!!!!!!!

 

What year is your jeep?

Sounds lime a failing check valve, but more info is needed.

 

1994 Jeep Cherokee Sport 4.0L HO i6 AX15 NP231

 

torres is the same jeep or after 4 wife wants to know lol

 

90-120 psi

 

WHAT?

It's 41 or so at idle and 49 at idle with the hose to the fuel pressure regulator removed.

 

Yeah them numbers where crazy high, exact numbers are 40-52psi i believe.
Ive had that problem, and it was my fuel pump cutting out. Check the pressure at the rail as stated, go from their. It also should gradually loose pressure and not just drastically drop.

 

For your 1994 Jeep 4.0 engine, you should see 31 psi at idle. Then disconnect the vacuum line leading to the fuel pressure regulator and the pressure should jump to approximately 39 psi. Verify this with a fuel pressure gauge; no shortcuts.

 

LOL
4 different Jeeps, 1 ex-wife later and still have the fourth...

 

Because mine looses fuel pressure siting from the check valve in the pump or the injectors, if I just turn the key on for a few seconds, a few times, that primes it.

I did find this;

Some of those specs that are hard to find in any workshop manual.

The following is a list of the injectors used on the 4.0L since 1987 along with their rated static flow:

Model Year, ...Part #, ...........Colour, .....Fuel Pressure, ...Static Flow,
'87-'90, ........53003956, .........Black, ...........39psi, .................18.6lb/hr
'91-'93, ........33007127, .........Brown, ..........39psi, .................21.0lb/hr
'94-'95, ........53030343, .........Tan, ...............39psi, .................21.0lb/hr
'96-'98, ........53030778, .........Grey, .............49psi, .................23.3lb/hr
'99-'04, ........04854181, .........Blue tip, ........49psi, .................22.5lb/hr
'05-'06, ........53013690AA, ...Brown tip, .....49psi?, ...............23.3lb/hr?

 

cruzer54: my bad, 60-120 is textbook for A good running car! (fuel rail pressure)