Aftermarket fuel injectors ok? 2016 CX-5

[cdmain]

Hi all,

I am looking at getting one fuel injector replaced on my CX5 2016 2.5L petrol. I was quote a $700 AUD for 1 injector from Mazda dealer and was wondering if people here have any experience with using after market fuel injectors.

It it recommended to stick with Mazda injectors or are aftermarket ones like Bosh good to use.

Thanks.

Regards,
CD

 

[Lazy2.5]

Just curious what sort of symptoms you experiencing related to fuel delivery?

 

[Conrad 16.5]

Yes, what was the issue?

 

[cdmain]

Happy to share the issue, just was not sure if it was relevant to this thread.

I bought my cx5 second hand so I don't have the whole history of the vehicle. The issue I have is intermittent misfire on idle. I felt it when sitting in the car in and then put a scan tool on and when I ran the Mode 6 tests , it indicates misfire counts for the cylinders. Cylinder 4 is the worst. On the other cylinders the misfires appear randomly. But almost consistently on cylinder 4. Sometimes when sitting in the car I can see the count increment slowly but continuously on cylinder 4.


What have I done thus far:

Took it to a mechanic who swapped coils and spark plugs and checked for vacuum leaks. I also did a carbon clean on the intake valves . Misfire symptoms remain.

I have yet to do a leak down test or change ignition coil #4 wires. However mechanic thinks the issue could be a dirty fuel injector on cylinder 4.

There are no codes or engine light and car drives well on full throttle.

Mazda fuel injectors are very expensive , dealer quotes $700 AUD for 1.

I am schedule for the engine leak test this weekend. If those results are good then would be considering fuel injector or sparkplug wires.

Mechanic tells me it also could be work out cam lobe but I think that is unlikely as I have not heard of that being an issue with CX5.

So there you have it. That is what I am dealing with and I would love to finally get to the root cause of the misfires.

 

[HyFlyer]

How about run a tank of gas with fuel injector cleaner ?

 

[Lazy2.5]

Yes, try that first. And don't just throw money and parts at the car without knowing what the issue is. Does the car smell strongly of fuel? Stand outside the car while it's idling warm. No smell of fuel from exhaust? Is the oil smelling strongly contaminated with fuel If you smell what's on the dip stick?

$700 for a single injector is absolutely nuts.

 

[Lazy2.5]

I doubt it's your injector to be honest.

 

[yrwei52]

Happy to share the issue, just was not sure if it was relevant to this thread.

I bought my cx5 second hand so I don't have the whole history of the vehicle. The issue I have is intermittent misfire on idle. I felt it when sitting in the car in and then put a scan tool on and when I ran the Mode 6 tests , it indicates misfire counts for the cylinders. Cylinder 4 is the worst. On the other cylinders the misfires appear randomly. But almost consistently on cylinder 4. Sometimes when sitting in the car I can see the count increment slowly but continuously on cylinder 4.


What have I done thus far:

Took it to a mechanic who swapped coils and spark plugs and checked for vacuum leaks. I also did a carbon clean on the intake valves . Misfire symptoms remain.

I have yet to do a leak down test or change ignition coil #4 wires. However mechanic thinks the issue could be a dirty fuel injector on cylinder 4.

There are no codes or engine light and car drives well on full throttle.

Mazda fuel injectors are very expensive , dealer quotes $700 AUD for 1.

I am schedule for the engine leak test this weekend. If those results are good then would be considering fuel injector or sparkplug wires.

Mechanic tells me it also could be work out cam lobe but I think that is unlikely as I have not heard of that being an issue with CX5.

So there you have it. That is what I am dealing with and I would love to finally get to the root cause of the misfires.

Firstly, fuel injectors usually are reliable if you keep using good quality gas. If they get partially clogged, you can always try fuel injector cleaner such as Techron.

Secondly you have misfire registered but apparently the count is still within the allowable range and you don’t get the CEL and any related DTCs. I wouldn’t worry too much about occasional misfire as long as there’s no misfire CEL.

Doing the compression test and leak-down test is a good idea.

Are you using correct OEM spark plugs and OEM ignition coil packs? That’s the parts I’d spending some money on to resolve occasional misfire issue.

 

[cdmain]

You guys are super helpful as always.

I forgot to mention that I did run the fuel cleaner in gas tank 4 times consecutively.

3 times with liqui moly fuel system cleaner and followed up with techron fuel system cleaner.

No change.

Ok ignition coils are oem. Spark plugs were oem , replaced with ngk iridium. No change.

One thing I noticed was that the ignition coil wires on cylinder 4 have a black tape put on that looks different to all the other coils. Also it had pulled back as if something hot touched it , so I put some rubber tubing around it.

Not sure if the ignition coil wires are the culprit but then it shud not be misfire only on idle and also not so infrequently.

I will do the leak test and then report back.

I too don't want to spend that much on minor issue but it's also annoying me that I have not gotten to the cause.

 

[cdmain]

Regarding good quality gas , here is Australia we have 91 Ron, 95 Ron and 98Ron.

To be honest I always used 91Ron from which ever fuel station was the cheapest.

Mechanic tells me I shud have only been using fuel from BP or Shell as they maintain their underground tanks clean and also to use only 95 or 98Ron. Which is what I have been doing since running the fuel cleaners and then changing spark plugs.

 

[Lazy2.5]

Can you feel the misfire or rough idle? If no cel, don't worry about it.

 

[yrwei52]

You guys are super helpful as always.

I forgot to mention that I did run the fuel cleaner in gas tank 4 times consecutively.

3 times with liqui moly fuel system cleaner and followed up with techron fuel system cleaner.

No change.

Ok ignition coils are oem. Spark plugs were oem , replaced with ngk iridium. No change.

One thing I noticed was that the ignition coil wires on cylinder 4 have a black tape put on that looks different to all the other coils. Also it had pulled back as if something hot touched it , so I put some rubber tubing around it.

Not sure if the ignition coil wires are the culprit but then it shud not be misfire only on idle and also not so infrequently.

I will do the leak test and then report back.

I too don't want to spend that much on minor issue but it's also annoying me that I have not gotten to the cause.

“Spark plugs were oem, replaced with ngk iridium. No change.”

Do you have Mazda OEM spark plugs; p/n PE5R-18-110, or NGK Laser Iridium spark plugs, ILKAR7L11 / 94124? Be aware there’re plenty of counterfeit NGK spark plugs around.

If you noticed the ignition coil wire on cylinder 4 is suspicious, may be you can compare it to an new OEM wire or replace the wire for cylinder #4 if possible.

I still believe your misfire problem shouldn’t related to your fuel injectors.

 

[AL Cx5]

Yes run a compression and leak down tests. Also, what does #4 spark plug look like compared to the others? They are very easy to remove. Maybe post a pic of all 4.

If an injector is getting plugged up, it will run lean and the plug will show signs of lean conditions or melted ground strap or worst melted piston.

Air cleaner condition?

What codes if any are showing up.

If I thought it was an injector, and I don't, I would pull all 4 and have them cleaned and flow tested. I have an injector flow test machine for fuel rail type injectors and ultrasonic cleaner. It's a very easy process.

Let us know what you find out after a compression and leak down tests.

Your tech may have missed the vacuum leak, vacuum leaks are hard to find sometimes.

Oil look OK, not milky or brown from water. That would indicate an head gasket.

Exhaust smoking white or other color?

Also, clean or replace your MAP sensor. Have a look at your O2 sensors. Either of these could make it stumble at idle.

Has your gas mileage the same or dropped?

 

[yrwei52]

Regarding good quality gas , here is Australia we have 91 Ron, 95 Ron and 98Ron.

To be honest I always used 91Ron from which ever fuel station was the cheapest.

Mechanic tells me I shud have only been using fuel from BP or Shell as they maintain their underground tanks clean and also to use only 95 or 98Ron. Which is what I have been doing since running the fuel cleaners and then changing spark plugs.

At least in the US, Mazda recommends 87 API (91 RON) octane regular gas for our 2.5L NA, and suggests NOT to use any thing higher on octane as it won’t help to increase the horsepower. The only benefit to our 2.5L NA IMO is higher octane premium gas usually has more detergents to clean up the fuel systems.

So just stick with good reputable gasoline from name brand such as Shell. 91 RON is fine.

 

[yrwei52]

⋯ If I thought it was an injector, and I don't, I would pull all 4 and have them cleaned and flow tested. I have an injector flow test machine for fuel rail type injectors and ultrasonic cleaner. It's very easy process.

 

[AL Cx5]

I have an EFI race car that burns Methanol. Meth is hard on all the fuel components. It will foul injects. I have two sets of injects. 8 cleaned and tested, 8 on the engine. It only takes a few seconds lean to ruin an engine. I also have 8 ET sensors tied into the ECU. If a hole goes lean, the ECU kills power. Burning 2 gallons in 7 seconds there is not a lot of room for error...

I clean my friends injectors for fun. It only takes a few minuets.

 

[cdmain]

@Lazy2.5 i feel the car vibrate ever so slightly when sitting in the drivers seat on idle.

@yrwei52 currently I have the ILKAR7L11 installed. I also kept the Mazda plugs. Yes I read about the counterfeit ones. But seeing as the issue did not change or get worse....

@AL Cx5 Will send a pic of spark plugs later tonight. Engine air filter is newish, looks clean. MAF sensor cleaned, throttle body removed and cleaned. Also I took out the intake manifold and cleaned the intake valves.

MAP sensor and O2 sensors I have not checked. How do I clean / check these?

Oil and exhaust looks normal. Except my friend did the dollar bill test, holding a piece of paper up to the tail pipe and it was fluttering . But leak down test tell me with more certainty if something is wrong.

If the mechanic missed a vacuum leak then I'm going to upset . I spent a lot of time troubleshooting this LOL.

Gas mileage is pretty similar, but was better with the Mazda oem plugs I reckon 7.6L/100 km vs 8.2L/100km.

I don't have the machine to clean the injectors, if it comes to that I will ask the mechanic for a quote.

I am scheduled in for the leak down test this Sat.

 

[cdmain]

@yrwei52 mechanic was adamant that I bought this on myself by using 91RON from cheap fuel stations. Since using 98RON I do feel the car responds well under full throttle and also fuel economy is marginally better than 91RON.

Read somewhere the Mazda retards the timing if using 91RON.

My car is a 2.5L NA incase I did not already mention this. It does not need the higher octane but maybe the fuel cleaner additives are a good thing...who knows.

 

[cdmain]

@AL Cx5 Got the plugs out and posting the pictures.

I also had stored the OEM mazda plugs that I was using until 57,000km and now have switched to NGKs . Current odo at 59000km.

Cylinder 1: looks very black compared to the others. Have not had too many misfire counts from this cylinder.

Cylinder 2:

Cylinder 3:

Cylinder 4: The one with the misfires

Comparison between OEM vs NGK


Cylinder 1:

Cylinder 2:

Cylinder 3:

Cylinder 4:

 

[cdmain]

Also sending this picture showing the ignition coil wires #4. I added the black tubing because for some reason the black sheath (as seen on #3) had pulled away.