Jeep

Have Jeep questions? Ask a Jeep repair expert for answers

Ask an Expert,
Get an Answer ASAP!

This answer was rated:

Vapor lock after it sits for a while, hard to start with…

Vapor lock after it...

Vapor lock after it sits for a while, hard to start with rough idel until new fuel gets in there

Mechanic's Assistant: Is the rough idle intermittent or consistent?

Well more persistent when going from cool weather to hot weather, that is 40 in morning to 80 in afternoon

Mechanic's Assistant: Are you fixing your 80 yourself? What have you tried so far?

I do not turn tools anymore, the engine has 367,000 miles on it and runs well except for this issue

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

I just need direction, i have insulated the fuel rail and injectors and this helped for a while

Show More
Show Less
Ask Your Own Jeep Question
Answered in 1 hour by:
3/22/2018
Canuck Tech
Canuck Tech, Technician
Category: Jeep
Satisfied Customers: 704
Experience: 20 years experience in tune up, electrical and general repair
Verified

Hi there - year and model and engine size of your jeep?

Ask Your Own Jeep Question
Customer reply replied 3 months ago
2001 Cherokee, 4L

This one isn't too tough.

Returnless fuel system. Pressure is most likely bleeding down through the fuel pump check valve. Drop the tank, replace the pump / fuel level sender / regulator assembly.

Also a possibility of leaking injectors at this mileage.

When the fuel pressure drops on a hot engine, fuel vaporizes in the rail. Because it is a returnless system, the fuel vapor has to go through the injectors, in order to get liquid fuel to the injectors.

Black spark plugs on one or two cylinders could be an indicator of a leaking injector(s)

If the oil level increases in the crankcase, leaking injector for sure

Ask Your Own Jeep Question

Hope that helps. Please close up the question, and rate my service. Regards, Canuck

Canuck Tech
Canuck Tech, Technician
Category: Jeep
Satisfied Customers: 704
Experience: 20 years experience in tune up, electrical and general repair
Verified
Canuck Tech and 87 other Jeep Specialists are ready to help you
Ask your own question now

Thank you for trusting Just Answer with your Automotive questions. Canuck

Ask Your Own Jeep Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a jeep mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Canuck Tech Your Own Question
Canuck Tech
Canuck Tech
Canuck Tech, Technician
Category: Jeep
Satisfied Customers: 704
704 Satisfied Customers
Experience: 20 years experience in tune up, electrical and general repair

Canuck Tech is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Thank you so much for your answer. My initial estimate was $325; I got it done for $100 - part and labor.

Lynn B.Ormond Beach, FL

I was skeptical at first but thought I'd give it a try. I was pleasantly surprised. Your site actually is a quality service that I would recommend to others in a heartbeat.

StanSayre, PA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

< Previous | Next >

Meet the Experts:

Chris

Chris

Shop Foreman

3,578 satisfied customers

Jeep Certified Master Tech

Mark

Mark

22 Year Factory trained technician

2,649 satisfied customers

Jeep factory training........25 years in the industry.

Dave

Dave

Jeep Master Tech

1,149 satisfied customers

Chrysler Triple Master, ASE master Tech AA degree in Auto.

moparfl

moparfl

ASE Certified Technician

1,130 satisfied customers

ASE Master Tech Chrysler Dodge Jeep Master Tech

Tim Mohr

Tim Mohr

ASE MASTER TECH

1,052 satisfied customers

30 YRS EXPERIENCE, FOREIGN AND DOMESTIC, GAS AND DEISEL

Ron Z.

Ron Z.

- Jeep Tech -

641 satisfied customers

18+yrs experience. State Inspector & Jeep Diagnostics/Repair

jeepmopar76

jeepmopar76

Jeep/Chrysler Triple Master Tech

579 satisfied customers

32yr ASE Master Tech, 9yr Chrysler Master Tech, 19 yr Jeep Dealership service including AMC/Eagle

< Previous | Next >

Related Jeep Questions
Jeep Wrangler: I own a 1992 jeep wrangler with a 4.0 6 cylinder.
I own a 1992 jeep wrangler with a 4.0 6 cylinder. I am experiencing difficulty in starting. I changed the crank position sensor but it did not help. The engine will turn over repeatedly but does not w… read more
Chris
Chris
Shop Foreman
3,578 satisfied customers
2003 Jeep: runs great..wont start..30 mins starts fine..Fuel pressure
2003 Jeep 4.0L runs great but wont start when hot, when cools off, 20-30 mins starts fine. Replaced fuel pump, filter, and crank position sensor. Fuel pressure 50psi when running but off the dial, 100… read more
Chad
Chad
Lead Auto Tech/Shop foreman
Associate Degree
858 satisfied customers
Jeep Cherokee Sport: I have a 2001 Jeep Cherokee Sport that
I have a 2001 Jeep Cherokee Sport that I have owned for about a year now. When I got it the check engine light was on, so I had it checked, which it gave a code for a misfire in #3 cylinder. I could f… read more
Brad
Brad
Technician at Dodge Dealership
Vocational, Technical or Trade Scho
12 satisfied customers
Cherokee Country: a faulty fuel injector (I..fuel rail..fuel line
Fuel delivery problem, 1997 4.0 Cherokee Country. I had a faulty fuel injector (I assume) which was over-pressurizing the fuel rail. The fuel line kept popping off or bursting. I replaced all the inje… read more
Randall
Randall
Auto Technician / Consultant
Vocational, Technical or Trade Scho
69 satisfied customers
coil pack, cam sensor and crank postion sensor..im getting power
Hi Dave, I thought we had this figured out but it started with the crank several times before it starts again. I replaced the coil pack, cam sensor and crank postion sensor. I'm getting power to the c… read more
Dave
Dave
Jeep Master Tech
Associate Degree
1,149 satisfied customers
1996 jeep grand cherokee: cold weather..warmed..three cranks to get it
I have a 1996 jeep grand cherokee with a 4 liter engine that is starting hard in hot and cold weather. When it is 50 degrees out it starts on the first crank, but as it gets warmer or if the car is wa… read more
brownjeff
brownjeff
Associate Degree
13,873 satisfied customers
Super: It acts like it is vapor locking on short hot trips sometimes .
Hi Super Mechanic hope you are well. We need your help on our 2001 jeep cherokee sport again. It acts like it is vapor locking on short hot trips sometimes . Sounds like there is a miss or vapor lock … read more
supermechanic
supermechanic
Service consultant
Vocational, Technical or Trade Scho
10 satisfied customers
2004 Jeep Wrangler: 4.0L..idles rough..start running..was running fine
My wife just called me here at work. She says my 2004 Jeep Wrangler (4.0L) is hard to start, idles rough, and dies when she gives it the gas. I told her to let in run for ~5 minutes to see if if would… read more
DODGETECH2875
DODGETECH2875
Vocational, Technical or Trade Scho
1,004 satisfied customers
2000 Jeep Cherokee: liter..the dealership..engine turns
I have a 2000 Jeep Cherokee 4 liter that i have had since it was new. Once a year the same problem returns and the dealership can not find out why. The engine turns over at its regular speed but does … read more
CDJMasterTech
CDJMasterTech
Lead Automotive Technician
High School or GED
813 satisfied customers
94 Jeep Cherokee: 000 miles..driven..it wont start..it cools down
94 Jeep Cherokee - 50,000 miles. Replaced electric fuel pump and now when vehicle is driven and I stop at a location and try to start vehicle it won't start until it cools down!… read more
b5demon
b5demon
Automotive Technician
Vocational, Technical or Trade Scho
1,522 satisfied customers
95 grand cherokee: awhile..fuel lines..blow..lines it runs fine
i have a 95 grand cherokee that after you drive for awhile it is like it is getting vapor locked you take the fuel lines off the fuel filter and there is way more pressure than normal the fuel filter … read more
Doug In North Carolina
Doug In North Carolina
Automotive Service Technician
Vocational, Technical or Trade Scho
173 satisfied customers
96 Grand Cherokee: restart..rough..stumbling..gear until I
96 Grand Cherokee LTD. Starts and runs okay. After a brief shut down, 5 minutes or so, It will restart and idle very rough, stumbling even in gear until I push the gas and move about 100 feet. Then it… read more
b5demon
b5demon
Automotive Technician
Vocational, Technical or Trade Scho
1,522 satisfied customers
fault on my on board computer...2 or 3 of my cylinders were misfiring
I have had a fault on my on board computer. The old fault was "multiple engine misfire" Like 2 or 3 of my cylinders were misfiring. Anyways.... I put new spark plugs and put a new ignition coil rail i… read more
Mark
Mark
22 Year Factory trained technician
Vocational, Technical or Trade Scho
2,649 satisfied customers
2000 JEEP CHEROKEE: GETS HOT..AIR CONDITIONING..FEW MINUTES..cylinder
I HAVE A 2000 JEEP CHEROKEE WITH 62000 MILES BOUGHT IT NEW HAVE HAD ONE PROBLEM FROM NEW WHEN IT GETS HOT OUTDOORS 85 OR HIGHER AND YOU USE THE AIR CONDITIONING FOR A SHORT OR LONG DRIVE AND YOU STOP … read more
CDJMasterTech
CDJMasterTech
Lead Automotive Technician
High School or GED
813 satisfied customers
jeep wrangler sahara: it shakes and when i push..backfire..bang..engin
i Have a jepp wrangler sahara 4.0, 2001. i have been putting my car in the shop constantly now on some of the starts it shakes and when i push on the gas it does nothing then you pump the gas and it s… read more
CDJMasterTech
CDJMasterTech
Lead Automotive Technician
High School or GED
813 satisfied customers
4.0L../>Drives fine except when outside air temp is 80 or higher
92YJ 4.0L 5sp 64K miles. Drives fine except when outside air temp is 80 or higher. While driving in hot weather, the engine occasionally "cuts out" complete loss of power, sputters then dies. Wait 20-… read more
moparfl
moparfl
ASE Certified Technician
Vocational, Technical or Trade Scho
1,130 satisfied customers
Jeep 2001 4.0 engine . the check engine light keeps turning on .
i have a jeep 2001 4.0 engine . the check engine light keeps turning on .have relace computer 2 timed coils 1 time sparkplugs 3 times cam sensor 1 time each time it shows # XXXXX misfireing. have repl… read more
Mark
Mark
22 Year Factory trained technician
Vocational, Technical or Trade Scho
2,649 satisfied customers
2004 Grand Cherokee: with a 6 cyl..rough idle..coil rail..troubleshoot
I have a 2004 Grand Cherokee Special with a 6 cyl. I developed an increasingly rough idle and suspect that it may have to do with the coil, coil rail and maybe a fouled plug or two? How can I troubles… read more
Mark
Mark
22 Year Factory trained technician
Vocational, Technical or Trade Scho
2,649 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x