I got a check engine light come on. My XJ has been taking turnovers to start since i got it a few months ago. Was told maybe fuel pressure, but not serious and as didn't bother me, was not too concerned. Did as usual yesterday with key turn, wait, turn again and then light came on. Any thoughts?

 

Have codes read. MY list of possible causes, will take all day for you to read. No idea what "taking turnovers" is. Bad fuel pressure can lead to serious issues along with minor issues, 2 examples are Burned valves or bad MPG.

 

Guessing is futile. Must have the codes read. Use the technology provided to you by your Jeep.

For a 2000, you will need either a code reader or a scan tool. The "key-on, key-off" technique that worked with older XJs won't work with your 2000.

Autozone will read your codes for free if you have one near you.

When you get the codes, post the EXACT code or codes here, not just a description. With OBD, the devil is definitely in the details!

 

Thanks for both the above, and am having codes read tomorrow. Have noticed what I think is pretty bad MPG - currently around 14, does that sound low?

ETA... "taking turnovers" a typo. What I meant was takes a couple of times to start. I turn key, it cranks but no engine fire up. Turn back, turn again and then it ALWAYS fires. Never needs more than that, that's why I never thought it was that serious.

 

Read this. It is so common, that I have it in a "cut and paste" format!
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The check valve is located on top of the gas tank and is part of the fuel pump assembly on 95.5-2001 vintage 4.0 XJs. When the check valve starts to fail, it reduces fuel pressure to a point where an extended crank is needed to start the engine. It is a very common failure. I experienced it on my 99 at around 75K.

A good (and simple) way to troubleshoot this problem is called “the poor mans prime”

1. Turn key to ON position (do not crank the engine!)
2. The fuel pump will energize and run for a couple of seconds
3. Turn key to OFF position
4. Repeat above a two more times
5. NOW crank the engine over

If the engine starts quickly and cleanly after performing this procedure, you may have the check valve issue. If it starts and runs poorly for a few seconds, it could also be a leaky fuel injector resulting in the bleed down and the stumble upon startup is the engine clearing the excess fuel that has leaked into the cylinder because of the faulty injector.

Also be aware that a bad battery can give you this symptom. Sounds strange but it definitely does happen. Have battery load tested if you have any questions; your XJ does NOT like low available battery voltage. Be sure battery connections and posts are CLEAN.

Some troubleshooting tips for extended crank times:

Hook up fuel pressure gauge on the schrader valve on the fuel rail

Start engine and bring to normal operating temperature.

Observe test gauge. Normal operating pressure should be 49.2 psi (plus or minus 5 psi)

Shut engine off.

Pressure should not fall below 30 psi for five minutes.

If pressure falls below 30 psi, it must be determined if a fuel injector, the check valve within the
fuel pump module, or a fuel tube/line is leaking. An adaptor tool/hose included with the fuel pressure gauge can help you with this. Consult gauge manual for more information on this but here is basically how it works:

*Turn the engine off and immediately clamp the fuel line at the adaptor hose. Watch the pressure gauge and see how long it takes to lose pressure.

*If the pressure remains at 49 psi for an extended period of time then the problem is in the tank - possibly the check valve. If the pressure falls below 49 psi fairly rapidly then the problem is probably a leaky fuel injector.

You can limp a check valve problem along indefinitely if you wish as it doesn't mean the fuel pump itself is going bad. Normally, the check valve is replaced as an entire assembly as you have to drop the gas tank to access the assembly. Fuel pump assembly consists of fuel pump, regulator, check valve, filter. If you do replace the fuel pump assembly, purchase a high quality OEM style unit. Some cheap aftermarket assemblies don’t hold up and fail prematurely. I specifically seek out Bosch fuel pumps as they are the best in the business. Stay away from Airtex, as IMHO, they have a bigtime reliability problem.

 

this sounds exactly like my problem. would this result in a check engine light ever? and do you think my MPG is low (around 14)?

 

No. The check valve problem will generally not set a check engine light.

For your gas mileage, get at least three samples before coming to any conclusions. You must do the math. Miles driven divided by gallons consumed. Extrapolating your mileage by miles driven to a tank of gas isn't particularly accurate. Post those three numbers here for comment.

In general, yours I believe is rated at 16 mpg city, 21 mpg highway, same as my 99. And that is where my mileage numbers come in.....between 16-21.

 

If it helps you out I get 14-15 in town and 22 on the highway

 

The check engine light was a misfire as a result of the long crank to start up. Been checked out today. The long crank is cus the fuel pump is not holding pressure in the tank and will need to be replaced. Going to get it done. Using after market one its $200 cheaper, but still going to run $500 in parts and labour. damn.

 

man thats alot to do a one hour job

 

i know what you mean, but the pump itself is 290... and i have not got the skills or contacts to do any other way.

 

Do NOT install an Airtex fuel pump. The problem threads with them is off the chart.

Bosch is what I specifically seek out for fuel pumps. Best in the business.

 

thanks for the warning. will make sure not airtex and insist on bosch. would it still be around 290? and whats the noise level on them?

is there any other brand to be wary of too, just in case i can't get a bosch in time?

 

what was the number/description of the code you pulled?

 

not only do you need a new mechanic you need to get you parts some where else also this place is high priced but not as high as you statedhttp://www.jeep4x4center.com/product...mber=5012953AC