samf

this is a Fuel-injected 1994 jeep cherokee sport - inline 6 engine has always been good and reliable.

recently replaced water pump, don't know if that has anything to do with it. Made a bit of a noise after new installed, thought bearing was seating in, noice disappeared.

Now, it MAY start and may not, and I probably need to jump it to get enough turns. fuel seems to reach plugs intermittently.

but once it's running, it runs fine like it always has.

a mechanic suggested bad fuel pump as a possibility.

my question is, I have all the basic tools but no test equipment. Is test/replace something I could do myself? and generally, has anyone else experienced this same thing? Again, you'd never think it has a problem once it's running..

Thanks,
Sam

EastBeast

Is the battery good? And the ground is solid?

tjwalker

A water pump in no way could create this symptom. All the water pump does is move coolant; no electrical involved.

1. Remove battery cables. Clean them and the battery posts until they are SHINY. Connections often overlooked.

2. Freshen grounds. More below

3. Load test battery. Any parts store will do this for you for free.
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Grounds can be the root cause of many electrical gremlins. Refreshing grounds is NEVER a bad idea, and the investment of your time in this procedure is always well worth it!

You can't tell much of anything by looking at ground connections!! You must remove, scrape, clean until shiny the cable/wire ends and whatever they bolt to. Be sure to remove all paint from any ground connections.

Start with the one on the back corner of the head, and where it attaches to the firewall, as it deteriorates over time and is an area that makes it susceptible to damage. Best to replace that woven cable with a #4 or #2 gauge cable. You can attach the one end to the intake manifold if you would like.

Next go over to the engine dipstick tube stud. Remove the nut and clean the wire ends and scrape the block until shiny at the stud. Reattach tightly.

If you are so inclined, add at least a #6 cable from the negative terminal of your battery to one of the bolts on your radiator support.

caged

is the check engine light on?

samf

YES, the battery and grounding is good. I can crank her all day long - well, almost

NO, the check engine light is not on nor has ever come on

NO, I realize the water pump has nothing to do with this

Bottom line, the engine will "jump" a little a times like it got a bit of fuel (it is fuel-injected remember), but then goes back to "dry" cranking.

again, sometimes I can get it started, AND ONCE STARTED IT RUNS AS BEAUTIFULLY AS IT HAS EVER RUN.

So, I guess my real question is, HOW DO I TEST FUEL PRESSURE.

Thanks, I am grateful for the help and if you ever need help with PHP programming I help out at phpbuilder dot com

Sam

tjwalker

Fuel pressure is tested by installing a gauge (can be rented from some parts stores) on the schrader valve on the fuel rail. Look for the valve that looks like a bike tire valve.

Just because it cranks doesn't mean that the grounds are good. Freshening them (removing,cleaning,reinstalling) is never a bad idea.

Be sure your tuneup hardware is fresh. Old tuneup hardware is bad news as you need a strong secondary ignition to fire up an engine.
Fresh champion copper plugs gapped to .035, new plug wires, distributor cap and rotor.

residentg

This may not be very helpful, but in scanning old posts I recall reading about something that controls the fuel pump in 2-stages: one for starting, and one for running. The poster had a similar problem and it ended up being this device / unit. A resistor in the engine copartment perhaps? I cannot remember much more, but maybe someone else can chime in. Thank you. JB

TintedOutXJ

Did u figure this out? Im having the same issue. Hard to crank but once running its golden.

Fsher21

I say load test the battery and go from there, as stated above. The marginal battery is always a good place to start. Just throw another battery in if you have one to check if you can't get it to the auto parts store.

chill

temp sensor. tell ecu that the engine is cold so it acts like a choke. runs more fuel till it warms up.