Medium and Heavy Trucks

Have truck repair questions? Ask an Expert

Ask an Expert,
Get an Answer ASAP!

This answer was rated:

I have a cat c12 I have a issue where it sounds like I have…

I have a cat c12...
I have a cat c12 I have a issue where it sounds like I have air in my fuel things I done replaced all fuel lines suction and return fuel regulator transfer pump fuel lines from pump to ecm fuel lines from ecm to filter housing hand primer pump all injector o rings all o ring in fuel rail had a guy tell me I had bent valves changed for nothing 3 sets of fuel filters
Show More
Show Less
Ask Your Own Medium and Heavy Trucks Question
Answered in 5 minutes by:
1/15/2018
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 9,305
Experience: I am ASE Master Truck Certified.
Verified
Thanks for asking your question. I will try and help you out.
Can you elaborate on your question please?
When you say It sounds like you have air. Do you mean you have low power?
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Power is fine i can go threw the low side never break up soon as I get on high side it breaks up in 7th gear acts as if it's not getting fuel
Thanks for the information.
Has the fuel pressure been checked while driving?
Does the yellow check engine light come on while driving?
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
I put a gauge on but don't know how trustworthy it is but it reads about 85 at idle but as soon as you rev it goes past 120
Customer reply replied 4 months ago
Haven't seen a check engine light truck is old might not work
Thanks for the information.
120 is too high. It should remain between 70-90 psi at all times. If there is a return line restriction. It can casue low power and high fuel pressure.
Ask Your Own Medium and Heavy Trucks Question
Thanks for the information.Since the check engine light does not come on, I would suspect 1 of 2 things are causing your problem.The first is low fuel pressure. If there is a low fuel pressure problem, the check engine light will not come on and the engine will have low power. Your engine should maintain a fuel pressure between 75 and 90 psi. There is a plug beside of the secondary fuel filter that is used to check the pressure. If it is low, I would first try the fuel filters if you haven’t already. If it is still low, you may have a failed fuel pressure regulator, which is located underneath the bottom of the filter housing. I have replaced a ton of these for low fuel pressure. It is kinda a known problem. You could also have a weak fuel transfer pump or restricted hand primer pump, if your engine has one.Second I would suspect you have a low boost condition. This can be caused by a leak in the air piping or air to air aftercooler on the truck. I would first inspect all of the piping to see if there is a hole in any of the rubber boots that hold the pipes. From there you may want to cap off one side of the air to air cooler, and pressurize it. They have been known to crack and leak and cause low boost.Please let me know if you need more help or have more questions.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
I replaced all of those things I started with fuel filters the fuel regulator then transfer pump then fuel lines hand primer pump then injector o ring then fuel rail orungs I do notice that my return pressures going into tank is more less a thin stream that's not strong
Customer reply replied 4 months ago
Turbo sounds strong
Thanks for the information.
If your turbo has a wastegate. It could be sticking or leaking.
You could also have a leak or crack in the charge air cooler.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Will that make it sound like I'm running out of fuel
Customer reply replied 4 months ago
I run straight pipes so you hear it
it will.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
you saying I'm having a air issue from the turbo
A possibly low boost issue with the turbo.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
A couple of weeks ago the airline that goes from to intake to the air compressor had came off and it made a weird noise after it did I don't know if that's something strange
Customer reply replied 4 months ago
How certain are you on the issue of the turbo I spent a lot of crazy money in the last month trying to get this truck back together
I just know if there is no light and low power. I always find low or high fuel pressure. Or a leak in the air system or faulty turbo.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
That's the thing I really don't have low power my power is fine it's just hesitant but it still picks up speed normally it just cracks and sputter and then it'll go
I see. Normally when you have a fuel pressure issue or turbo and air issue. You have low power.
Since you do not have low power. I must suspect an injector or injectors issue.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Not giving any codes had technician ride with me gave a code for2 solenoid change injector still do it
your getting a code for number 2 injector?
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
I haven't put back on computer
Customer reply replied 4 months ago
After I changed it
I see. Sounds like an injector issue.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Wouldn't a injector do it all the time
Customer reply replied 4 months ago
Soon as I put the computer it shows no fault codes
Customer reply replied 4 months ago
Computer shows no codes
No not always. I have seen them be intermittent
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
how do I figure that out
Sometimes you can run a cylinder cutout to isolate and find the problem injector.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
This the thing all injectors was rebuild warranty just ran out
Customer reply replied 4 months ago
Does the fuel return to the tank at 70 to 90 psi
No. The regulator holds the pressure between 70-90. After the regulator the pressure is much lower.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
What are the chances of my spring weaking and not holding enough tension would I have more pressure are trouble when sat for a while and not starting
Not common to have spring problems on injectors. Normally problems with injectors are internal.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
No I'm talking about the fuel pressure regulator spring
A spring problem can cause that.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
I stretched the spring and it got worse it's doing it on the low side now
I’d try replacing the regulator
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Do secondary fit filter housing have something to do with it could have been a pressure regulator be sticking on the inside of their

You could have a cracked filter housing. I have seen that before.

Ask Your Own Medium and Heavy Trucks Question
Hey. I just wanted to see how things were going. Please let me know if you need more help. I am happy to assist. If my information was helpful, please leave a good or higher rating so that I receive credit. Thanks.
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 9,305
Experience: I am ASE Master Truck Certified.
Verified
Cat Man and 87 other Medium and Heavy Trucks Specialists are ready to help you
Ask your own question now
Customer reply replied 4 months ago
Was sick I changed the filter housing it got a lot better but still hiccuping in 9th and 10th gear I changed regulator spring but I didn't change the fuel regulator I noticed that the fuel regulator in the old filter housing was jammed in there I put it in the new one and it you could put it in easy slide it and it and turn it upside down and it slides back out should I have change the regulator to get rid of the the last of that air
Thanks for asking your question. I will try and help you out.
Yeah I would change it.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Can't get one till monday
10-4. I’m glad the problem got better.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Noticed that the return pressure in the tank is a lot higher it's making bubbles in the tank from stream pressure and regulator had some suff marking on it think this should solve it
i agree.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Let you know monday
10-4
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 4 months ago
Changed the regulator no change in it but the filter on side of frame is not filling up with fuel normally when lossen fuel would overflow its under half full could i have brought a faulty transfer pump and will cat warranty cover it
Thanks for the information. Yes it’s possoble the new pump is bad. It has a one year warranty.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
Ok paid for new pump not problem answer this if you over adjust the injectors when running rack could that give me and issue
Customer reply replied 3 months ago
I turned the adjustment more than it requires to get more fuel
Thanks for the information. Actually turning the adjustment has no affect on more or less fuel delivery. But an improper adjustment can cause the engine not to run correctly.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
I have a gauge on it pressure at idle is a bouncy 75 to 80 put max load it goes past 110 plus
Customer reply replied 3 months ago
I have a gauge on it pressure at idle is a bouncy 75 to 80 put max load it goes past 110 plus what cause that
That pressure is good.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
not a fuel pressure problem
Does not look like it.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
Where do I look now
Customer reply replied 3 months ago
Go back and reset rack to factory specs
I would.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
Previously I had issue with it cracking and popping and blowing white smoke you helped on that find out it was a Jake brake issue back Jake off truck ran perfect explain in dummy terms how to do Jake setting with filer gauge
It’s not hard. Just insert the feeler gauge under the Jake foot and adjust til there is a slight drag on the feeler.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
What's the set point for gauge
What’s the engine serial number?
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
9ns03052
For a 9NS it should be 0.040
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
I talked to a old school mechanic and he told me to put some additive in and I finally notice improvement tomorrow I'm draining that fuel and putting fresh fuel back he says I might got bottom of tank fuel and didn't know it and the cold weather made water and it's trying to burn the fuel but the water mixture causing compression issues sounds about right
water in the tank can casue issues like this.
Ask Your Own Medium and Heavy Trucks Question
Customer reply replied 3 months ago
No change in it I did pull a load with it got up to 75 at one point but bucking piping along the way empty would just pickup speed faster
Was this answer helpful?
Ask Cat Man Your Own Question
Cat Man
Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 9,305
9,305 Satisfied Customers
Experience: I am ASE Master Truck Certified.

Cat Man 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:

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

2,322 satisfied customers

Owner at DJ Wilson

Cat Man

Cat Man

Cat Engine Expert

9,305 satisfied customers

I am ASE Master Truck Certified.

Wayne

Wayne

Journeyman

2,640 satisfied customers

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

Jeremy

Jeremy

Certified Truck/Bus Technician

2,019 satisfied customers

ASE Med/HD Truck Technician, NATEF Diesel Engines and Electrical/Electronics Technician, EPA 608/609 HVAC Certified, Steering/Suspension and ABS/Brakes Technician

cumminsdr

cumminsdr

Mechanic

1,225 satisfied customers

All types of Cummins applications

Curtis B.

Curtis B.

Technician

813 satisfied customers

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

dieseldan55

dieseldan55

Contractor

74 satisfied customers

Road Service mechanic for Volvo Construction.

< Previous | Next >

Related Medium and Heavy Trucks Questions
2019 579 Peterbilt. I've done the 10 min parked regen, the
2019 579 Peterbilt. I've done the 10 min parked regen, the guages now show clean. But warning still up. I had to stop the process manually, does it shut off itself after 10 mins?… read more
Andy3221
Andy3221
truck /coach technician
Vocational, Technical or Trade Scho
222 satisfied customers
I have a Series 60 # 06R0672408. I need to do a valve
Hi. I have a Series 60 # 06R0672408. I need to do a valve injector and engine brake tune up. All the info is gone from the valve cover. Could you please tell me what the specs are? Intake, exhaust, in… read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
2,640 satisfied customers
Machine just stopped running. Engine is free and turns over.
Machine just stopped running. Engine is free and turns over. Panel light indicates low oil pressure. Added oil but still will not start. Low oil pressure light still on. Help … read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
2,640 satisfied customers
2014 Freightliner Cascadia with OnGuard system. Received
2014 Freightliner Cascadia with OnGuard system. Received error SA 11 SPN 629 FMI 14 ECU Mounting, Accelerometer Not Plausible The measured lateral acceleration is not plausible or the learned offset i… read more
roy
roy
Associate Degree
3 satisfied customers
Cat man, I have a 2000 466e also.. it starts all the time no
hello cat man, I have a 2000 466e also.. it starts all the time no problems hot or cold. but if I drive it it will run great for a short distance the the engine warn light comes on and it loses power … read more
Andy3221
Andy3221
truck /coach technician
Vocational, Technical or Trade Scho
222 satisfied customers
I have a New Holland TC45D that is just dead. Worked fine,
I have a New Holland TC45D that is just dead. Worked fine, shut it off for a couple minutes and went to start. all dead, nothing comes on including glow plug light, etc. Voltage goes from 12.7 to abou… read more
Curtis B.
Curtis B.
Technician
Associate Degree
813 satisfied customers
I am having trouble with a C11 acert engine. The engine will
I am having trouble with a C11 acert engine. The engine will barely accelerate and often has at least 3 active injector codes when the engine is running. The engine cranks right up and doesn't need st… read more
Cat Man
Cat Man
Cat Engine Expert
9,305 satisfied customers
VOLVO TD100A setting of the injection pump. 69028/16006 150
The pump is at the test bench right now and need to put it back myself . Just need the proper reference … read more
Steven
Steven
Triage Tech/Shop Foreman
Associates
10 satisfied customers
Have a 2014 Mack CXU613 VIN# 1M1AW09Y4FM052308,,, sometimes
have a 2014 Mack CXU613 VIN# ***** sometimes when you turn the key on nothing happens, try to start and all the lights come on cycle then the all lights go off again.... sometimes it comes on like nor… read more
Wayne
Wayne
Journeyman
Vocational, Technical or Trade Scho
2,640 satisfied customers
I have code 253-2 on MXS cat motor after I re rated to 550
Hi my name is***** have code 253-2 on MXS cat motor after I re rated to 550 and no throttle response if I gave you the serial number on injectors could you e mail me the injector trim files?… read more
Cat Man
Cat Man
Cat Engine Expert
9,305 satisfied customers
No power in the. Have no power right now first time checked
Have no power right now first time checked fuses all good … read more
Steven
Steven
Triage Tech/Shop Foreman
Associates
10 satisfied customers
I have a 2011 isuzu nps300 dual cab serialn. Need to know
Hi Pearl, JA: What is the complete model and serial number of your machine? Customer: I have a 2011 isuzu nps300 dual cab serialn JA: Are you fixing this yourself? What have you tried so far? Customer… read more
Andy3221
Andy3221
truck /coach technician
Vocational, Technical or Trade Scho
222 satisfied customers
We have a new holland c 190 with a new pump new control vale
we have a new holland c 190 with a new pump new control vale new cylinders and its still cavitating … read more
Curtis B.
Curtis B.
Technician
Associate Degree
813 satisfied customers
2008 maxxforce DT Starts cold won't start hot!! Replaced
2008 maxxforce DT Starts cold won't start hot!! Replaced ipr , huei pump, high pressure oil seals… read more
Andy3221
Andy3221
truck /coach technician
Vocational, Technical or Trade Scho
222 satisfied customers
I've been having a problem with a c15 acert engine in a
I've been having a problem with a c15 acert engine in a M1977A4 Oshkosh HMMET. It always starts just fine, sometimes it'll run for 1-2 minutes and sometimes it'll run for 3 seconds. It always runs lon… read more
timdieseltech
timdieseltech
diesel tech
Vocational, Technical or Trade School
57 satisfied customers
Looking for some to explain ECM/ECUS and how they relate to
Looking for some to explain ECM/ECUS and how they relate to fuel flow. I have certain question I could provide … read more
Steven
Steven
Triage Tech/Shop Foreman
Associates
10 satisfied customers
I have a komatsu wa450-5l serial a36497. We recently rebuilt
I have a komatsu wa450-5l serial a36497. We recently rebuilt the engine. After installation will not run unless the ne sensor on bellhousing is disconnected. Flywheel does not have a dowel to locate p… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
2,322 satisfied customers
1998 dodge cummins will start but revs on its own and
1998 dodge cummins will start but revs on its own and accelerator is not responding … read more
Andy3221
Andy3221
truck /coach technician
Vocational, Technical or Trade Scho
222 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