Misfire on rough running engine. No CEL

Hi rmurdock, Welcome to 2carpros

This sounds like you have a fuel injector that is not working right if you pull the spark plug is it white like nothing is happening in the combustion chamber?

If so I would remove the injector to test it here is a guide.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Check out the diagrams (Below). Please run this test and get back to us.

Cheers

Greetings:

I did what you said and the injector is not opening so I got a new one for $67.00 and installed it the engine has never run better. I love this site.

Thanks for your response.

Good to hear, please use 2CarPros anytime we are here to help.

Cheers

i want to know how much it cost for a new cylinder.
1- cylinder is missing and also my linkage is loose

you can't purchase just one cylinder. if it is missing then you may simlpy need a tune up (new spark plugs and wires, fuel injector cleaner etc..) . if the cylinder wall has scratches then you will need a new or rebuilt cylinder head..

So what about the linkage being loose it has something to do with the transmission? thanks a bunch in advance!

You talking about the shift cable linkage?? If so you will need to follow steps below to adjust it..

Hi, my vehicle is running on four cylinders and should be running on six. It had been to an auto electrician and had new spark plugs and a coil pack replaced and it still seems to be running very rough and has not much power. A mechanic has had look and is still not sure what the problem is because he said the two cylinders that rant running are firing up and working but the cars not picking them up. He said it may be in the fuel line and has put some cleaner in with my petrol to see if it cleared it up and it notice last night my fuel pump is leaking and my exhaust was glowing bright red. Would you have any idea of what may be the problem?

Sounds like he has just about thrown every part on there. Find out which two cylinders are misfiring. Remove the fuel injectors for that cylinder misfiring and swap with a good cylinder. If the misfire follows that cylinder then your fuel injectors are bad. If it does not then you need to have a compression check and cylinder leakage test. As far as the fuel pump is concern, you will need to have the pump replace.

ok backstory I'm cheap I buy cheap pieces of junk fix them drive them for a few years sell them and usually turn a profit this escape makes me want to go the way of the dinosaurs I picked it up for 300 body great condition engine has a miss he swore no body ever tried to fix it it was dark and the notary was about to close so I paid the money thinking id fix and this would be my daily driver fast forward the next morning I pop the hood I notice valve covers are both leaking bolts are loose upper intake plenum bolts are loose random bolts are missing everywhere I think its all good a couple gaskets and shell be good to go so heres the list the misfire was due to a genius having coil on plug wires reversed it misfired for so long the cat all melted so I had to cut exhaust of to get it to even stay running once I had her running with new coil on plugs and spark plugs I noticed it idled horribly up and down in park and neutral and just down in drive or reverse my scanner shows it would idle between 550 and 850 not in gear and between 350 and 500 in gear so I decide to replace a few things since it wasn't throwing codes I did upper and lower intake gaskets both valve cover gaskets iac valve tps sensor cleaned the maf replaced pcv checked for vacuum leaks with carb cleaner couldn't find any fast forward again she does run better about 750 in park or neutral fairly steady but any strain on motor dropps the idle ac running light on putting a window up and most importantly putting in gear my scanner shows around 600 in gear after it levels but when you first throw it in gear it drops to about 200 I would say sometimes it stalls depending if you have heater on or not my oil pressure light flickers in gear I'm assuming because of idle speed being so low and raise in rpms shuts the light off I just gave it an oil change 5w 20 as manual stated I put synthetic in after I gave it an oil change now my valves are ticking fairly loud at idle they quiet when raising rpms to about 1500 fast forward driving to work yesterday I finally got a code misfire cylinder 4 hooked my scanner up fuel injector cylinder 4 dead replaced yesterday major power increase and whe I un plug coil 4 it actually makes a difference in engine performance now so that's good I guess so I'm driving after injector change and I notice it spits and sputters on acceleration for the first minute or so of driving now it does it at start off in first and when trying to give it gas in overdrive it sputters bad so bad you have to floor it to make it upshift but like I said it only does it for about a minute then levels off it thru me another code yesterday cylinder 4 misfire again so I was thinking maybe plug is fouled because of not getting any gas for three days while it was running on 5 cylinders so I swapped it no more sputtering until today its at it again for the first minute of driving it does it also still have low idle and engine oil light flickering and any load on engine tries to kill it unless I give it gas ps ive also tried resetting pcm learned values and reteaching it which did make it stop stalling in gear but it stills idles horribly low


so current symptoms sputtering for 1 minute after intial start usually worse when cold

really low idle in gear dropps to 200 then levels out

any load on engine tries to stall it

ticking coming from front and rear valve covers gets quieter at about 1500 in park

flickering oil light in gear I believe may be due to low idle not sure sometimes flickers in park but only when engine is warmed up

sometimes when cold engine idles nice for about 5 min even in drive around 750 to 800

I wanted to add something when it sputters when you first started it seems like its struggling to find fuel I do not have a fuel pressure tester so I haven't tested it yet and I do have a new fuel filter but I haven't put it on yet my question is can a clogged fuel filter or a bad fuel pump make your computer only throw a code for cylinder for it is the farthest away from the pump itself but I have no car genius so I don't know about that

I also haven't done a compression test on that cylinder because I haven't got that old yet and I haven't done and oil pressure test to see if I really AM low on oil pressure at idle my main concern is the low idle in the sputtering

and the ticking valves after I change the oil

also wanted to add that it didn't sputter until I change the new injector when it was running on 5 cylinders and didn't stutter It didn't run that good but it didn't stutter at all and the valves didnt tick until after I change the oil

oh and if you're thinking timing I don't know much about timing all I know is that it starts right up within three or four rotations of the engine

and when I said I had to cut the exhaust off to get it started all I cut off was the rear cat and the muffler the front cat bank 2 melted and sent all of it to debris into the rear cat which clog the whole exhaust so it still has bank to cat and bank 1 cat on there so I don't know if bank to cat might still be clogged if these symptoms fit a clogged cat let me know and I'll cut it off right now

one last thing when idling the pedal is not very responsive it takes awhile for it to come back down when you hit the gas it's more responsive than it was when I got it but it's still fairly unresponsiveI've already clean the throttle body thoroughly

by the waythe oil pressure light goes out at about a thousand Rpm

if you don't put new isolater bolts on intake it WILL have a vacuum leak. try a good oil filter like wix, Purolator, napa. if oil pressure still low it will shut your fuel pressure off so bearings may be bad if filter not the problem. then scan for codes and check fuel pressure with a gauge auto parts rent it. they can scan as well for engine codes.

Ithas new isolator bolts on it the filter is a Purolator I ran seafoam thru you don't think some sludge could be caught in pickup screen

and could fuel pressure cause one cylinder to misfire I'm seriously asking the head because most vehicles that I've had misfire they were random misfires when it was a fuel issue but like I said I'm not an expert I have no clue I'm just trying to figure it out I'll get a fuel pressure tester tomorrow I'm pretty sure its not a compression problem because it doesn't have any of the symptoms of a compression problem it has power loss of power I live in Pennsylvania and I can go up a pretty steep hill at 50 miles an hour and no problem I'm really thinking it's something stupid I was wondering if you could tell me what vacuum lines on there are supposed to have vacuum if I pull them off and put my finger on it I do not know much about vacuum lines but I know that I checked a couple of them and the lines coming from the valve covers that go it into a tea that go into the air breather they don't have any vacuum on them the EGR doesn't have vacuum when its idling but I'm not sure if that's supposed to the only ones that I seen that have vacuum or the brake booster and the one that goes from the throttle body to what I'm assuming is some fuel modulator

the lines going from the valve cover to air duct /breathers are not vacuum only the pcv is if you are good with a scanner freeze frame it and check your voltages if a sensor is bad can cause that also check grommets for air leaks. i'll send a vacuum diagram in next email because our site has changed and I can't do it on a reply.

see pic

I recently changed the spark plugs gaped them to specifications, changed the spark plug wires, the cap that goes to the spark plug wires and it still getting a misfire in cylinder 4. I'm thinking that it may not be getting fuel since that is the only cylinder with the misfire and also it isn't throwing out any other DTC
s besides the P0304 code.

You could check the fuel injector with a test light to see if it is firing and then pull the plug to see if it is getting wet with gas.
You can always check it for spark by pulling the plug and putting the plug into the boot and ground it out on the engine or chassis.
If all that works, you might want to test the compression on that cylinder and possibly the fuel pressure.
Autoo Zone and Advance Auto loan out tools for both tests.

where are the fuel injectors located on this car is it underneath the air intake

If you look in line with each spark plug going down towards to head, you will see the injector in the head .
You can find the fuel rail if you can see the fuel regulator or where the fuel ine comes in. The fuel injectors will have this rail attached to the top of them as well as a positive and negative wire going into them, look for wiring harness.
These are the 2 wires you want to test with a test light to make sure the injector is completing the circuit and firing as they have a solenoid in them that moves to let gas in the cylinder.

ok so i did a compression check and said to say it but all cylinder came out fine except for cylinder number 4 no compression at all so what problems am i looking at for this. head gasket piston rings?

That is correct. You might have an igniton problem, unlikely, or carbon deposits on high mileage cars can melt holes through pistons. There are other reasons for mechanical damage such as oiling failure. However most likely is the head gasket.

I’m very certain it is not the coil since I swapped it with the number 1 coil and that cylinder is performing fine and number 2 is still misfiring with code P302.

However, the car was driving fairly well for about 5 miles before it started to misfire again after the coil swap but less often. I’m thinking it is the wire and or connector leading to the coil. My question(s) is (are):

What is the best way to diagnose this without mechanic/specialized diagnostic tools? I have a multimeter and a code reader but that’s it.

Assuming it is the wire/connector and I can buy one (I see them online), where does the other end terminate? Do I just unwrap it fro the rest and trace it back?

Can I replace the whole wiring harness? If so what is its part number and where can I buy it?

Lastly could it still be something else? If so what?

Thanks for your help.

Hi KnightsTour, Welcome to 2carpros and TY for the donation

P0302 A misfire in a specific cylinder should lead you to check the sparkpug,compression and injector for the that cylinder and probable causes of misfiring below

1.Defective spark plug
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
10.Throttle position sensor.
11.Idle air control valve.

okay so if i remember correctly the head that is closest to the engine would be the RH gasket and the one furthest away would be the LH gasket right

WIFEY HAS A 2003 W/ A 3.0L

THIS WAS AN ISSUE WITH HER'S THAT I WORKED ON HITHER AND YON, FOR MONTHS

I PROMISED MYSELF, I WOULD FIGURE OUT THE CYBER CONTROLLED CRITTER WITHOUT THE HELP OF A "PAY MECHANIC".......TECHNOLOGY HAS WENT OVERBOARD...I'LL KEEP MY 2 JEEPS 35 AND 66 YEARS YOUNG


Reckon my symptoms are sorta the same as yours?

I had input from here also....ended differently

Disregard all of this, if we're not on the same country road

Thought I'd sling it out there, for observation anyway....open for any questions with mine....hope it's simpler than mine!

I Went thru same deal w/ '03 Ford Escape 3.0 V-6

Repetitive, fast hesitations (stumbles), lasting 1-2 seconds, varied in how far the "sets" were apart, it was more evident climbing a incline, while slowly administering gas....random or none on level ground......Every now and again at idle, but very seldom.

---No codes/ No CEL --- (cleaned 1st, and/ or replaced the following

New Plugs............then "genuine plugs".....Bah-Hum-bug!!!, nothing wrong with the other new ones, I just installed!

Boots and springs

air filter

MAF

EGR

A new IAC for Sheets & Giggles! ....Prevent-Maint...if for nothing else

Performed Mega Vacuum leak searches several times.

Fought with wife many times over situation, 2+ months!

I really hated taking off the "Plenum" so many times to access the other 3 cylinders

Each part seem to fix it for a day or two....I did not mind replacing the suggested parts, as I am all for "PM" and she's got 100,000 miles on her rig.

The final cure was #3 misfiring (lucked into the correct cylinder) I was gonna swap a new coil pack down the line, till it stopped

#3 was the ticket!

I had tried to get the Technical school to ride me with their portable machine---things did not work out, with their schedule.

I went to a salvage yard to get a used pack ($10) to swap around to figure out which was bad, then buy a new one, if the "donor pack" solved the problem.

So happened, the salvage yard guy had a machine, he found a stored code, it said #3 had misfired.....My little code scanner could not tell me that!.....I think his was a "Snap On"

Runs perfect now, with the New $79 Coil Pack!

IF IT HAD NOT BEEN FOR THE STORED CODE, I WAS GONNA "ONE AT A TIME" SWAP THE COIL W/ THE 1ST EZ 3 TO FIND THE MISFIRING ONE......IF IT HAPPENED TO BE ONE UNDER THE "PLASTIC PLENUM"

THE PLAN WAS TO TAKE OFF AND REPLACE THE PLENUM ONE TIME ONLY!!!---BUT SWAP THE "3 GOOD" FRONT COIL PACKS TO THE REAR.....THEN "TEST" THE 3 EZ FRONT ONES (RELOCATED FROM REAR) ONE AT A TIME WITH THE "DONOR COIL PACK"

THE STORED CODE MADE IT EZ ON ME, LOCATING THE BAD PACK

THE MEDIC

I SORTA RECKON I MISSED THAT YOU NOW MAY HAVE A COMPRESSION ISSUE....WHEN I CLICKED IN GOOGLE CHROME THE AUG 25ths POST WAS ON MY SCREEN AND I .......... DISREGARD MY BABBLING ABOVE

THE MEDIC

thanks for the info but like i said I did a compression test and cylinder number four had no compresssion in it at all the others were fine but back to my question the head gasket that I need to change which is the one closest to the front of the vehicle is the RH gasket right

1 min ago

FIRT TIME LIKE TWO YEARS AGO I CHANGED ALL GASKETS TOP AND LOWERS THE PROBLEM WAS FIXED AND THAT TIME MOTOR WAS UNSTABLE
TODAY IT IS ALMOST THE SAME PROBLEM I CHANGED GASKETS AND THE PROBLEM STILL BUT AND THEN I CHANGED ALL THE SET WIRE ON COILS THE PROBLEM WAS FIXED. 6 MONTH WITHOUT PROBLEMS WORKING GOOD ( AUTOZONE LIKE 40 DLL COST SETWIRE)

Engine light codes misfire in cylinder one.i have replaced plug coilpack no vacuume leak.vehicle hesitates when starting from stopped position.dont know what to do from here.vehicle does this when warm.

You have to eliminate all the common ignition issues first but this vehicle has a known problem with burning out the PCM drivers for the coils. IF that is confirmed, the solution is to replace all the coils and the PCM which will require programming.

Hello. I have had the check engine light on for 2-3 months. My car did not pass inspection and the mechanic told me there was a problem with my spark plugs. I replaced them and reset the battery but the engine light came back. Recently it got bad enough that I dont want to drive my car until the problem is fixed. The engine shakes a lot at 65mph or higher, the car cannot accelerate going uphill, and one point the car slowed down so much that I had push the gas pedal all the way down which bumped my engine rpm to 7000 just to maintain a constant speed of 50 mph.

Yesterday I scanned the OBD and got codes p0302 and p0303 which says that cylinders 2 and 3 are misfiring. I replaced my air, fuel filter, and battery about a year ago. The spark plugs are new. The wires are worn but I dont see any damage to them. All other components are original from when the car was bought (about 4 years ago from the previous owner). After close examination it seems that my car is slowly leaking transmission fluid. Any ideas on what the problem could be? What should I check next? I will change the transmission fluid as soon as I get a chance but I doubt that will solve the problem.

Thanks.

Check the sparkplug, compression and injector for those misfiring cylinders