Medium and Heavy Trucks

Have truck repair questions? Ask an Expert

Connect one-on-one with {0} who will answer your question

I have a 99 Freightliner FL 80 with a cat 3126. It is acting…

Customer Question
Hi, I have...

Hi, I have a 99 Freightliner FL 80 with a cat 3126. It is acting like it is running out of fuel. I have replaced the filter, and have checked it several times. One time, the filter was only half full. I had this problem this afternoon, filled the filter, topped off my tanks, and went to about 100 miles before it started losing power again.

Mechanic's Assistant: What's the make/model/year of your truck? Engine type?

99 Freightliner FL 80. Catapillar 3126.

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

I don't think so.

Submitted: 5 years ago.Category: Medium and Heavy Trucks
Show More
Show Less
Ask Your Own Medium and Heavy Trucks Question
Answered in 2 hours by:
8/6/2017
Technician: go-west.., Technician replied 5 years ago
go-west..
go-west.., Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 1,266
Experience: Technican with 20 years experience focused on engines and electrical.
Verified
Good evening
If there are no active codes then this biggest problem I've seen with these engines is the fuel pressure regulataor at the back of the head, the return fuel line to the tank is connected to it. It controls fuel pressure to the injectors and if faulty will not give the injectors the 65psi they need to operate properly, if ok, on some earlier Freightliners they used to use a inline canister style fuel filter, that a lot of people used to miss, trace the line from the tank to the inlet to the engine and make sure there isn't one. Good luck and let me know if you have any other questions.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 5 years ago
Thank you. I will look for that. This morning, it started right up, and is running fine now. I'll try to go down the road and see what happens.
Customer reply replied 5 years ago
I just went 20 miles and it started running rough again. I pulled the filter, the one on the engine, I don't have a primary, and it was only half full.
Technician: go-west.., Technician replied 5 years ago
Good morning
Let me know what you find with what I suggested.
Ask Your Own Medium and Heavy Trucks Question
Technician: go-west.., Technician replied 5 years ago
Good morning
How did it go?
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 5 years ago
It wound up being the fuel pump. They are putting it in now. That was an expensive pump. $1300.
Technician: go-west.., Technician replied 5 years ago
sir
There is no such thing as a cheap cat part.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 5 years ago
Thank you for your help.
Technician: go-west.., Technician replied 5 years ago
Np
Ask Your Own Medium and Heavy Trucks Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a technicianLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask go-west.. Your Own Question
go-west..
go-west..
go-west.., Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 1,266
1,266 Satisfied Customers
Experience: Technican with 20 years experience focused on engines and electrical.

go-west.. is online now

Related Medium and Heavy Trucks Questions
Can a c7 cat replace a 3126? No our engine bent pushrods,
No our engine bent pushrods , camshaft or lifter problem, was wondering what it would take to swap them out. … read more
Jeremy
Jeremy
Certified Truck/Bus Technician
Associate Degree
2,756 satisfied customers
I have a 2000 CAT 3126 that idles @ 70 psi fuel pressure but
I have a 2000 CAT 3126 that idles @ 70 psi fuel pressure but when you come off idle it begins to drop and it will actually go to 0 psi under a load and the engine still runs ok at psi till it eventual… read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
5,115 satisfied customers
I have a 2000 Freightliner Fl 60. Runs fine at times but
I have a 2000 Freightliner Fl 60 . Runs fine at times but sometimes it struggles going up bills to a point where it cuts off while going up hill When I restart immediately the check engine light is of… read more
Joe Green
Joe Green
71 satisfied customers
Have a freightliner fL 50 with a CAT 3126. The truck sat for
Hey i have a freightliner fL 50 with a CAT 3126. The truck sat for a few years but fired right up and shut its self down with an engine protection warning. I suspect the warning was due to low coolant… read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
5,115 satisfied customers
I have a 99 freightliner fl60 with a cat 3126 with huei
I have a 99 freightliner fl60 with a cat 3126 with huei injection system and I accidentally knocked a 10amp fuse out of the fuse panel in the cab on the passenger side while the truck was running.. on… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
6,062 satisfied customers
Fuel keeps getting low on a 3126 secondary fuel filter
fuel keeps getting low on a 3126 secondary fuel filter causing engine to shut down, Why? … read more
Mike Mcmillan
Mike Mcmillan
Triage Tech/Shop Foreman
Associates
604 satisfied customers
FOR CAT MAN ONLY PLEASE! DO NOT ANSWER IF NOT CAT MAN. I
FOR CAT MAN ONLY PLEASE! DO NOT ANSWER IF NOT CAT MAN. I have a 2000 F-650 pickup with a CAT 3126b in it. Approximately 3000 hours of idling time and drive time combined with only 51k miles on it. Got… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
Have an FL 80 Freightliner with 3126 engine that is
Have an FL 80 Freightliner with 3126 engine that is experiencing intermittently severe power loss. After sitting and cooling off power level return to normal levels only to relapse in an hour or two o… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
I have a 2001 freightliner with a C 15 cat engine serial
Hi, I have a 2001 freightliner with a C 15 cat engine serial number 6nz34593. truck seems to lose prime overnight, starts but takes a while. today after starting & driving over 100 miles(ran fine). Ki… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
Fl 80 freightliner wont idle up with cruise ecm says brake
Fl 80 freightliner wont idle up with cruise ecm says brake switch is on … read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
5,115 satisfied customers
Cummins 300 diesel engine loses power Full service 700miles
Cummins 300 diesel engine loses power Full service 700miles ago. Went 350 miles and lost power on hills, down to first gear and then engine died. Several times. Replaced fuel filter and went great for… read more
Curtis B.
Curtis B.
Technician
Associate Degree
1,947 satisfied customers
2012 freightliner cascadia Cummins. Any theory of scientific
2012 freightliner cascadia Cummins. Any theory of scientific degree, on why, I lose like one gallon and half of coolant almost instantly after filling ([withing 100 miles] but thereafter I don't lose … read more
Andy
Andy
truck /coach technician
Vocational, Technical or Trade School
214 satisfied customers
2011 cascadia DD15 Keep having the same problem multiple
2011 cascadia DD15 Keep having the same problem multiple shops have not fixed. Fuel System one tank will drain the other overfill - pressure will become so great as to cause the components to break an… read more
Expert
Expert
5 satisfied customers
I have a 6nz c15 cat in a 2002 western star. I loose prime
I have a 6nz c15 cat in a 2002 western star. I loose prime when my tanks are not full. I have changed the steel line from the transfer pump to the filter housing. Changed the filter housing, all fuel … read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
working on 2005 Freightliner M2 with 7.2 l Catapillar diesel
working on 2005 Freightliner M2 with 7.2 l Catapillar diesel engine. Was run out of fuel. I changed both fuel filters. I am having trouble priming fuel system. Secondary filter is full of fuel. There … read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
i have a 99 fl 60 with a 3126 cat in it and it wont start?
i have a 99 fl 60 with a 3126 cat in it and it wont start? i have no power to the fuel solinoid i changed the oil pressure switch it had a crack in it. what do i do next???… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
i have a 2002 Caterpillar engine model 3126 in a motorhome,
i have a 2002 Caterpillar engine model 3126 in a motorhome, how do i drain air in fuel line, or prime it?… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 satisfied customers
I am still having problems with my 3126 losing prime where
I am still having problems with my 3126 losing prime where is the lift pump located on the huie pump and do you have a picture of it. Is it hard to replace? I have a 02 6500 with a 3126 cat engine… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
5,353 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.

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:

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

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Daniel Wilson

Daniel Wilson

6,062 satisfied customers

Owner at DJ Wilson

Cat Man

Cat Man

Cat Engine Expert

5,353 satisfied customers

I am ASE Master Truck Certified.

Wayne

Wayne

Journeyman

5,115 satisfied customers

worked on, Gmc, Macks, Freight liner,Mercedes Benz,,Ford, sterling

Jeremy

Jeremy

Certified Truck/Bus Technician

2,756 satisfied customers

ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, Network Engineer specializing in CAN faults, Aftertertreatment, and vehicle communications

Curtis B.

Curtis B.

Technician

1,947 satisfied customers

Technician turned service manager on multiple lines of trucks and engines, used in industry.

cumminsdr

cumminsdr

Mechanic

1,886 satisfied customers

All types of Cummins applications

Chris (aka-Moose)

Chris (aka-Moose)

Technician

641 satisfied customers

24 years of experience diagnosing & repairing

< Previous | Next >

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