Chevy

Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP

Ask an Expert,
Get an Answer ASAP!

Chevy
This answer was rated:

On this 1998 ford ranger with a 2.5l engine, someone has…

Hey Ron. On this 1998...
Hey Ron. On this 1998 ford ranger with a 2.5l engine, someone has replaced the engine. it has a idling problem,at first start you have to keep feathering the gas to keep it running, then it will begin to idle on its own, but lopes up and down and smells rich out the tailpipe. but even thou it smells rich, I think its starving for fuel, after warm up, it seems to idle better. fuel pressure reads 50 psi.i think that's to low,i have vqcuum at the pressure regulator, but with the vacuum connected or not, doesn't seem to effect the idle, I took a hand vacuum pump and pumped it to 25 and didn't make a difference, do you think I have a regulator problem with this?
Show More
Show Less
Ask Your Own Chevy Question
Answered in 6 minutes by:
10/12/2017
Ron
Ron, ASE Certified Technician
Category: Chevy
Satisfied Customers: 37,217
Experience: 35 years experience with ASE Certs
Verified

Hello. My name is ***** ***** I am happy to assist you today. Give me just a moment to review your post, and I'll be right back with the help you need.

Ask Your Own Chevy Question

Normal fuel pressure on this engine needs to be 56 to 72 PSI so 50 is on the low side for sure. On a properly working fuel pump should jump the pressure up about 5 psi when you pull the vacuum line off the regulator. With the hose connected it should drop. This dose not sound like you have a bad regulator . Is the computer setting any fault codes?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
no codes are present.

This to me sounds like you have a fuel pump issue providing the filter is clear. I suspect if you can get the pressure up it may straighten this out.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
ok, thank you

Your very welcome and thank you as well.

Ron
Ron, ASE Certified Technician
Category: Chevy
Satisfied Customers: 37,217
Experience: 35 years experience with ASE Certs
Verified
Ron and 87 other Chevy Specialists are ready to help you
Ask your own question now
Customer reply replied 4 months ago
hi Ron. I am still fighting with this vehicle, I have tried 2 new mass air flow sensors. the first sensor solved the idling problem, idle good , no rich smell, but when raising the rpms it wouldn't, it started to buck and jerk backfire, the 2nd one makes the truck run like the original 1 I took off. I can unplug the mass air flow and it will idle good, but will stall after awhile,since I went and put some gas in this thing that was almost empty, the fuel pressure has come up to 55psi.have you got some suggestions on this

Are yo till not able to get any fault codes to set?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
had my scanner on it last night and no codes except for the air temp switch that I forgot to hook back up
Customer reply replied 4 months ago
what about a crankshaft sensor, is this wired thru the mass air flow

Its seems pretty odd that its not setting any fault codes and the Crank sensor is separate from the MAF . I wonder if the timing belt is properly aligned. When the engine was installed was the belt changed?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
they had that all apart and I installed a new timing belt kit. I had all the gears aligned like they were suppose to be

Dose it seam to have proper power once you get it off idle?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
I can rev it up. after warm up ,the idle does get a little better, but still smells rich out the exhaust

Have you gone back in and made sure all grounds are in place? If you place a linking light on it what happens to the timing dose it advance smoothly?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
i'll check and let you know

Okay, Im here all day.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
since this has spark plugs on both sides of the head, which wire am I going to hook a timing light to or does it not matter?

You will want to hook it to the number one # 1 spark plug One the exhaust side .

Ask Your Own Chevy Question
Customer reply replied 4 months ago
thank you

You bet, thank you as well.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
the timing advances when acc. it up

Okay then that should rule out a computer control issue. have you been able to get the computer to set any fault codes yet?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
just checked again and no codes. the little time I had it running, my eyes burn from the richness of the thing

If you fuel pressure is now with in specs I have to wonder if the computer is just bad, it controls the injector pulse. Was the computer matched with the replacement engine?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
probably not

I think because its not setting any fault codes that you should check and see if you have the correct PCM for this engine. You should be able to check this with the calibration number that should be on the door by crossing it over to the PCM number.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
my understanding is that the engine came out of something newer than 78
Customer reply replied 4 months ago
excuse me 98

That may very well be the problem, I would check and see if it has the correct PCM in it if you know the year of the engine.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
I just called the kid up and he looked at his receipt and he said the numbers from the vin are 170231. is that anything that you can tell me what the year is. also I had found where they had routed the alternator wires behind the exhaust and burnt the hot wire to the alternator in half and blew that 175 amps. could that go thru a circuit and hurt the ecm?

The charging system is not computer controlled but if you have a voltage spike that could have damaged the PCM. The number you have listed are not the vin number so I do know what they mean.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
I'm changing course . I pulled the vacuum hose off of the fuel pressure damper at the end of the fuel rail, it has 20 psi out of that hose, it isn't making any difference to the way its running, connected or not, does that mean anything, I thought the idle would change

Are you pulling the fuel pressure regulator vacuum line off?

Ask Your Own Chevy Question
Customer reply replied 4 months ago
I would call it a fuel pressure regulator, its in the fuel rail, but oriellys call it a fuel pressure damper, which must be correct, I found where the regulator is in the tank and part of the sender assy

When you pull the vacuum from the regulator the pressure should jump up a few pounds and it will not change the way the engine runs. If your only getting 20 PSI of fuel pressure that is a problem, this engine needs 56 to 72 PSI .

Ask Your Own Chevy Question
Customer reply replied 4 months ago
no, I have 20 on a vacuum gauge hooked to that vacuum hose

Okay the vacuum is fine. 20 HG of vacuum is good.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
but being plugged onto that valve, doesn't seem to change anything, according to what I found all that valve does is quiet down the injector noise, is that correct and it really doesn't have anything to do with fuel pressure to the injectors?

The vacuum line connects to the fuel pressure regulator and The only thing it will change is the fuel pressure should drop a few LBS and then when step down on the gas under load you loose the vacuum and the pressure should jump up a few pounds. The pules damper is just there to quite the injectors and has no effect on the way the engine will run. They are separate things as well.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
ok,thank you

Your very welcome .

Ask Your Own Chevy Question
Customer reply replied 4 months ago
I'm still not getting any codes, but watching live data on my scanner, I don't think I have any oxygen sensor activity. I am going to post the readings for you and let me know what you think.HEATER CURRENT O2S12 1000mA / HTR CURRENT O2S11 1000mA /HO2S BANK 1 SENSOR 2V .02 V/ HO2S BANK 1 SENSOR 1V 0.00 V/ HO2S BANK 1 SENSOR 2 LEAN / HO2S BANK 1 SENSOR 1 LEAN. THESE READINGS ARE WHEN ENGINE IS COLD. shouldn't this be showing rich with engine cold?

Usually they will not start switching till the engine goes into closed loop. Have you checked to see if you have power to the heater circuit for the HO2S sensors?

Ask Your Own Chevy Question

Its very odd that the computer is not setting any fault codes.

Ask Your Own Chevy Question
Customer reply replied 4 months ago
the fuse for that circuit is good.with the engine cold, shouldn't that be showing rich and not a lean condition?

There are two fuse for the fuel control, fuse #9 and fuse #13 both located in the under hood fuse panel. Start with making sure both are okay then then check for power to the HO2S on the heater circuit . Once other thing to check is the Ground for the HO2S circuit and that is the G108 located at the top center of the left fender apron. See the Circuit wiring diagram in the link below for reference .

https://www.dropbox.com/s/znirp5h4gcjbnan/HO2S%201%20Oct%2024.pdf?dl=0

https://www.dropbox.com/s/aeq3ixgmtil4axn/HO2S%202%20Oct%2024.pdf?dl=0

Ask Your Own Chevy Question
Customer reply replied 4 months ago
ok, I will give it a check

That would be a good idea.

Ask Your Own Chevy Question
Was this answer helpful?
Ask Ron Your Own Question
Ron
Ron
Ron, ASE Certified Technician
Category: Chevy
Satisfied Customers: 37,217
37,217 Satisfied Customers
Experience: 35 years experience with ASE Certs

Ron 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:

I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money.

Todd LRochester NY

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

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

Chevy Technician

15,289 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

Chevy Technician

9,357 satisfied customers

15 years GM master tech

Tim&#039;s Auto Repair

Tim's Auto Repair

mechanic

8,866 satisfied customers

Have owned a repair shop for 25 yrs.

Dave Nova

Dave Nova

Chevrolet Technician

7,092 satisfied customers

ASE Master Certification. GM World Class Certification

John

John

Master A.S.E Automotive technician

4,071 satisfied customers

A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician

Don - Mo Lurch

Don - Mo Lurch

Auto Mech / Electronics

2,918 satisfied customers

Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics.

Ron Z.

Ron Z.

- Chevy Tech -

2,734 satisfied customers

18+yrs experience. State Inspector and Chevy Diagnostics

< Previous | Next >

Related Chevy Questions
1997 Suburban: 5.7L, AT..backfire..Scan tool shows no dtcs.
1997 Suburban, 5.7L, AT, K2500 suddenly goes "No Start". Engine cranks good but all we get is an occasional backfire. Scan tool shows no DTC's. Fuel pressure 62 psi. Inline spark tester shows good spa… read more
Mcgruder73
Mcgruder73
Auto Technician
Associate Degree
0 satisfied customers
Pickup: coil..a Chevrolet 1500, with 5.7L V8..shaft
Trying to change the pickup coil on a Chevrolet 1500, with 5.7L V8 TBI. How do I remove the reluctor? It appears to have a bit of rust around the shaft, and at this point will not pry off. Does it pry… read more
Joecamel90
Joecamel90
Technician
Associate Degree
24 satisfied customers
How do you check for a collapsed lifter on a big block chevy
how do you check for a collapsed lifter on a big block chevy… read more
Ted G.
Ted G.
Technical/Sales Trainer
Vocational, Technical or Trade Scho
4,376 satisfied customers
After I change spark plugs on a 2005 Colorado my warning
After I change spark plugs on a 2005 Colorado my warning light came on. Took to Chevy mech and they stated that I needed a valve job.. Only misses when at a stop or traffic light and not all of the ti… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
I have a code of po300 common misfire spark plugs were
I have a code of po300 common misfire spark plugs were changed and the coil pack on plug 1 check engine light comes on for a few days then goes off for a few days trying to figure what's going on … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
I change the spark plugs I change the wires I change all
I change the spark plugs I change the wires I change all three coils I changed the gas card and I still getting the same code po300 lot of people is telling me that he could be the ignition module at … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
4,644 satisfied customers
I already change the spark plugs and wires on a Malibu 2003
I already change the spark plugs and wires on a Malibu 2003 Chevy it won't start … read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
Engine light on" clean exhaust filter continue to dric. Ve
engine light on " clean exhaust filter continue to dric … read more
BOBBYSS
BOBBYSS
TECHNICIAN/ADVISOR
Associate Degree
8,343 satisfied customers
Won't start, get spark from the spark plugs, have put gas in
won't start, get spark from the spark plugs, have put gas in the intact still won't start. Starter is turning all the belts … read more
heavy_chevy_396
heavy_chevy_396
Vocational, Technical or Trade Scho
2,518 satisfied customers
2014 Chevy Silverado 4.3 cylinder two misfire a spark plug
2014 Chevy Silverado 4.3 cylinder two misfire a spark plug is looks like it's wet with gasolineAlso engine code P0106… read more
Ron
Ron
ASE Certified Technician
37,217 satisfied customers
Pulled spark plug out and fuel came out with the plug.
pulled spark plug out and fuel came out with the plug. … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Misfire code p0306 I️ changer distributor cap spark plug and
Misfire code p0306 I️ changer distributor cap spark plug and wires new fuel pump don't understand why code is appearing … read more
Gary
Gary
Senior Technician
Vocational, Technical or Trade School
77 satisfied customers
Misfire in cylinder #1 replaced coil and spark plugs, engine
misfire in cylinder #1 replaced coil and spark plugs, engine light on and flashing. Put in injector cleaner also. … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
Crank ok but won't start when hot, fuel 55psi,spark plug
when it cold start up no problem,i even replace coolant temp sensor… read more
Michael Solis
Michael Solis
372 satisfied customers
1 cylinder Spark Plugs crack and misfire. Random at first
1 cylinder Spark Plugs crack and misfire JA: How many miles are on the car? Is it a steady misfire? Or random? Customer: Random at first 79000 mjiles JA: What is the model/year of your Chevy? Customer… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Crank, no start. fuel pump is working. spark plugs (I think)
crank, no start. fuel pump is working. spark plugs (I think) are firing. … read more
eric remington
eric remington
FORMER SHOP OWNER/TECHNICIAN/INSPECTOR
associates degree
309 satisfied customers
I'm trying to change the spark-plugs on my 2006 chevy
Hi,I'm trying to change the spark-plugs on my 2006 chevy Malibu,3.5 But I ran into a problem,a couple of the spark-plugs seem to be froze.they don't turn one bit.how can I get them out with out Breaki… read more
Eric
Eric
Auto Technician
589 satisfied customers
The check engine is on. I have changed all the spark plugs
Hi the check engine is on. I have changed all the spark plugs and core and ignition core. … read more
GM Tech (Cam)
GM Tech (Cam)
Chevy Technician
Vocational, Technical or Trade Scho
15,289 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