jefany4

I have a 92 auto Laredo 2 wheel dr. put a new starter and fuel filter in but still is hard starting(unless I pump the gas pedal)a few times then it starts easier. its an auto 4.0 inline 6cyl................any ideas?

thebyus

Could be the check valve on the fuel pump. Try turning the key two clicks so the radio is on and leave it for about 20 -30 seconds before actually starting. If it starts up fine, it's probably the check valve. Mine is toast, so this is normal starting practice on my rig as I'm not interested on dropping the tank skid and tank to fix it.

patnok

temp sender in front. it goes to computer. try replacing it it's cheap then go from there

jefany4

also does autozone stock this part?
thanks,jeff

JeepFreak02

Look at the injectors and coil the injectors might be clogged if you wheel it a lot. Coil could just be bad. If not, check your cap and see if it's in the right position

patnok

I would think. There are two temp sensors one in front, it tells the computer what the temp is so it can adjust the "choke", and one in back that goes to temp gauge on the dash. Also do a real tuneup with new wires,plugs,cap & rotor.

jefany4

I have a 92 jeep Cherokee 4.0,i replaced the starter and am seeing oil leaking at the oil filter housing area. I don't want my starter ruined because of this! is this an easy fix and maybe some steps on how to do it?
any help is good help.......im a novice.

Crazy 8s

Not a Cherokee but the procedure is very similar.

jefany4

so as far as the oil leaking at the oil filter area.............is this a part I can get at autozone? according to video........I need o rings and washers right? looks like 3 in the video.

jefany4

as far as hard starting........I do not wheel it,i use it for normal driving and is still hard starting runs smooth after starting though, so doing a full tune up would help? cause it doent run rough and reall want it to just start normal.

jefany4

so I did a full tuneup and is still hard starting unless I pump the gas a few times..........patnok said its maybe the temp sensor on the thermostat...........even if its cheap to replace and doesn't fix the hard starting.............then what? I am so tired of the maybe its this or that but I really appreciate the help........any ideas?

Synapse

I had the same problem a few years back. It ended up being a loose spark plug. Reach your hand down and see if you can wiggle any of the plugs. After properly tightened my old xj ran like a champ again.

ehall

It's almost certainly the check valve in the fuel pump. Very common problem. What happens is the fuel drains all the way back into the tank. Then when you try to start, the pump has to pressurize the line again, which takes a while (the long crank hard start).

AutoZone has a loaner fuel pressure tester that you connect to the schrader valve on the fuel rail. Minimum operating pressure on a 91-93 is 31 psi (more is better). With a good check valve the pressure will hold after you turn off the engine, with a leaky check valve the pressure will fall down to zero pretty fast as soon as you turn it off.

Assuming that's the case, you have two options. Cheapest option is get an inline fuel check valve from ebay, cut the soft line near the tank and put it in, that will keep fuel from draining out of the rail and line as quickly. Better long-term correct fix is to replace the fuel pump, since it is probably wore out anyway.

jefany4

first off thanks for the replies and since I did a full tuneup all the plugs and wires are correct..........about the cooling temp sensor........is that a waste of money? what I mean is it sounds like ehall has it correct there isn't pressure holding in the rail.there is a soft line coming off the fuel pump leading to the back side of fuel filter,is that where the check valve goes?also is the check valve like the fuel filter in that it goes in one direction only?also there was a lot of check valves on ebay when I searched............any specific one to use? I do appreciate everyone's time in helping me to solve this problem.

ehall

You need to verify that you are rapidly losing fuel pressure when the engine is turned off.

A check valve is a one-way valve, so it will let fluid leave the pump and go up the line, but is supposed to prevent it from draining back out. When the check valve fails, the fuel rail empties out and you have to crank to pressurize the line before it will start, and you have to do it every time.

If you verify that you are losing pressure rapidly, you can get these little in-line check valves on ebay for short-term fix. I got a pair of them for $10. The fuel line is 3/8"



There's a little arrow stamped on it that shows the flow. You can also blow through it, the direction you can blow through goes towards the engine.

These can only be used with the older models that have the pressure regulator on the rail (like your 92).

The long-term fix is to replace the fuel pump.