Hi, iv developed a miss-fire on my car the eml was flashing so I read the code it was misisfire on cylinder 4, I replaced the spark plugs and the ignition coil. Problem still there. I checked the injectors they were dirty and plastic was cracked so I replaced them. Now I have a missfire on cylinder 1 and 4 and there is a bit of black smoke out the exhaust any help would be appreciated.
Black smoke indicates it's running rich.
Did you use Denso injectors?
Following this thread with interest as I developed a misfire at the weekend and similarly, it manifested itself in cylinder 4.
Coil pack + spark-plug replaced, but still present.
Members on here have suggested o2 + MAF sensor checks and replacement.
I will also swap out all coil packs,spark-plugs and injectors (All Denso) asap when they arrive here.
If all of the above fails....maybe damp is getting at the ECU?
Yeah the injectors were all denso and I have done the usual swap plugs/coils to other cylinders still no change to the missfire location. I read somewhere about disconnecting the batter for 10 mins , disconnecting the 2 02 sensors and then the cam position sensor start it up and apparently it reverts the car to base map?? I will try this and I think I'm going to get it compression tested tomorrow
I also checked live data and one 02 sensor was reading between .9 and 1v and the other reading .8v to .9v
Ah - there you go!
New sensor on bank one then!
You can get a universal Denso that with come with crimp connectors to make use of the existing plug. Quite a saving on buying the specific one.
Quote from: Carolyn on March 23, 2023, 17:50Ah - there you go!
New sensor on bank one then!
You can get a universal Denso that with come with crimp connectors to make use of the existing plug. Quite a saving on buying the specific one.
Oh if I'm getting that reading is it because it's faulty I thought it was just because my engine is running rich ?
I have also tried disconnecting both 02 sensors and it is still running the same
It would run like rubbish with no sensors. The O2 sensors govern the fuelling.
The faulty sensor is a causing over fuelling.
The only sensor on the engine that affects only two cylinders is the O2 sensor.
Quote from: Carolyn on March 23, 2023, 19:01It would run like rubbish with no sensors. The O2 sensors govern the fuelling.
The faulty sensor is a causing over fuelling.
The only sensor on the engine that affects only two cylinders is the O2 sensor.
Just ordered one will fit it tomorrow when it comes hope this work thank you 🙏
I fitted the new 02 sensor now I think it has solved the misfires but it's still running rich , it's popping a lot and black smoke and it tells me on the code reader it's rich ? Any idea what this could be ?
I have also removed the Maf and sprayed with brake cleaner ?
Carb cleaner is better. Remove the O ring before you spray it.
The Maf is one item that does not throw a code. Replacing it with a known working one is the only way to reliably test it, unfortunately.
There's a few things that can make it run rich, but it's very much a trial and error process.
A failure of the fuel pressure regulator is also a possible culprit, but as the Maf is much easier to deal with, I'd start there.
Just bought some maf cleaner will try that thank you it's a lot better so thank you
Used the maf cleaner diddnt change anything ? Still running rich with no misfires. Got some reading the fuel trim when not on throttle is reading -20.31 on both bank 1 and 2. Maf air flow rate is 3.18g/s. Is the best thing to do next buy a new Maf ?
Readings on throttle?
Do they drop?
Anyone local that could possibly lend a known working one just to rule out.
As much as we like spending other people's money on unnecessary stuff.
We don't like spending on parts unnecessarily.
I've got a couple of used ones in my collection of bits. I'll put one in my car to rest it. If it's good I can send it to you for the cost of postage.
PM me with your address.
It's okay iv got one now it's coming Monday thank you anyways I think it was a cheep one from a previous owner as it also had some silicone around the seal and it doesn't say denso on it either
Quote from: Ardent on March 25, 2023, 18:44Readings on throttle?
Do they drop?
Anyone local that could possibly lend a known working one just to rule out.
As much as we like spending other people's money on unnecessary stuff.
We don't like spending on parts unnecessarily.
Throttle position was reading 12.16 at idle not sure it dropped but it does increase when reving will check if it drops tomorrow
Quote from: 2000mr2 on March 25, 2023, 15:15Used the maf cleaner diddnt change anything ? Still running rich with no misfires. Got some reading the fuel trim when not on throttle is reading -20.31 on both bank 1 and 2. Maf air flow rate is 3.18g/s. Is the best thing to do next buy a new Maf ?
The trim numbers are only valid in closed loop where they are reading the sensors. In open loop, they could be anything. If both banks are very negative on closed loop, look for something that would impact all cylinders, like a vacuum leak, intake leak, air filter or air intake problem, exhaust leak, etc. The MAF impacts all cylinders but is only one possibility.
I took the air filter out just for a short time to check, the exhaust is new and has no leaks, how would I check for vacuum leaks iv check pipes ext and nothing obvious is there a way to check leaks in the intake manifold ?
I read the live data and the throttle position doesn't go below 12.16. Also I'm pretty sure the trim numbers are a closed loop as it says it uses oxygen sensors in a closed loop. I also get codes p0175 and p0172 which show both banks are running rich.
Let's see what a new Maf does for you before we start with the inlet manifold!
The most likely vacuum leak is on the little hose that goes to the blue solenoid valve for the vapour recirc system.
The big vacuum hose that goes from the PCV valve on the cam cover to the inlet manilfold can also leak and cause issues.
But let's see what the Maf does?
Quote from: Carolyn on March 26, 2023, 14:07Let's see what a new Maf does for you before we start with the inlet manifold!
The most likely vacuum leak is on the little hose that goes to the blue solenoid valve for the vapour recirc system.
The big vacuum hose that goes from the PCV valve on the cam cover to the inlet manilfold can also leak and cause issues.
But let's see what the Maf does?
Yeah okay sounds good it comes Monday Tuesday fingers crossed it's just that
Any news
@2000mr2? , I am still following this thread with great interest.
Quote from: Gibla on March 29, 2023, 20:55Any news @2000mr2? , I am still following this thread with great interest.
People I bought the Maf from fucked me over I'm picking one up at lunch today and trying it
Language plse Dan >:( ;)
Just fitted it , it seams to drive a lot better and sounds better but the fuel trims still show it running rich and I have eml on for running rich on both banks,
Did you clear the codes or disconnect battery?
Quote from: mr2garageswindon on March 31, 2023, 15:51Did you clear the codes or disconnect battery?
Cleared all the codes
Yet still getting engine light?
Was it a new maf sensor? Or known working..
Quote from: mr2garageswindon on March 31, 2023, 16:26Yet still getting engine light?
Was it a new maf sensor? Or known working..
Brand new from a well known part company, and it runs better but still running rich.
I had it started for 10 mins reading codes all ran fine but fuel trim was still -20 but came down to about 0.8 when warm . Then took it for a blast and the eml came on telling me bank 1 and 2 are running rich .
However it feels fine to drive now.
Would mind popping the codes up.
(https://i.ibb.co/Q9VYjTf/IMG-2460.png) (https://ibb.co/Q9VYjTf)
What brand of new maf did you fit?
Quote from: 2000mr2 on March 31, 2023, 17:25Then took it for a blast and the eml came on telling me bank 1 and 2 are running rich .
Injectors.
I had the same problem.
A know working set sorted the problem.
Quote from: J88TEO on April 1, 2023, 18:15Injectors.
I had the same problem.
A know working set sorted the problem.
U know any places that sell them that are cheep that are good.
I got eBay ones but they say there denso and that there oem
I'm thinking fuel pressure regulator. It's a rare failure, but it does happen.
A used fuel pump assembly from J-Spec?
Quote from: Carolyn on April 1, 2023, 18:49I'm thinking fuel pressure regulator. It's a rare failure, but it does happen.
A used fuel pump assembly from J-Spec?
Is there any way to test to see if it is the pressure regulator? Or to test if it is the injectors ext.
when I replaced the injectors I replaced the o rings but not the insulators could it also be that ?
A pressure gauge in the fuel line is the way to test it.
Injectors require specialist testing equipment.
As you've replaced all four injectors with Densos, I think you can dismiss that one. (You'd expect at least one bank to be ok!). I can send you a set of known good ones if you'd like to try that.
The regulator is a part of the pump assembly and it might just be easier to put another assembly in. The regulator is quite expensive to buy new.
@Beachbum 's suggestion of looking for leaks in the inlet tract is usually a good one, except that extra air above the maf reading would result in lean rather than rich conditions.
I'm struggling to think of what else will cause rich running on all four, beyond the maf and fuel pressure regulator.
All suggestions welcome!!
Quote from: Carolyn on April 1, 2023, 20:01A pressure gauge in the fuel line is the way to test it.
Injectors require specialist testing equipment.
As you've replaced all four injectors with Densos, I think you can dismiss that one. (You'd expect at least one bank to be ok!). I can send you a set of known good ones if you'd like to try that.
The regulator is a part of the pump assembly and it might just be easier to put another assembly in. The regulator is quite expensive to buy new.
Thank you I believe I have a pressure tester about will try that how much should it be running at ?
And I can try my old injectors it wasn't running rich before I changed them it was just missfiring. But I know 2 of the old ones work so will try that too .
60 psi, as I recall.
Just a thought: I had it in my head that you have a new exhaust system. I've re-read the thread and I can't see you mentioning the exhaust. What exhaust manifold do you have, and have you checked it for leaks?
Quote from: Carolyn on April 1, 2023, 20:5060 psi, as I recall.
Just a thought: I had it in my head that you have a new exhaust system. I've re-read the thread and I can't see you mentioning the exhaust. What exhaust manifold do you have, and have you checked it for leaks?
It's a Milan manifold and I will check for leaks but would that cause it to run rich ? Iv had the exhaust on for a few months and it's been fine ?
Would that be 'Malian'?
Check it. A tissue flap taped to the end of a screwdriver will show any leaks. It could be leaking at the gasket, or it could have developed a split.
It happens.
The o/e manifold & cat pipe have recesses that crush ring gaskets fit into. The Malian doesn't. (hardly any aftermarket headers do) so what's in yours could be made-up or hybrid. The perforated gaskets that they come with are junk.
Quote from: Gaz mr-s on April 1, 2023, 22:03The o/e manifold & cat pipe have recesses that crush ring gaskets fit into. The Malian doesn't. (hardly any aftermarket headers do) so what's in yours could be made-up or hybrid. The perforated gaskets that they come with are junk.
The cat one shouldn't effect it as it is past the 02 sensors will it?
but I will definitely check the manifold gasket if it's bad I'll get a steel one.
Also yes it is a Malian one.
You might be right in your particular case, not sure. It's common practice to re-use the o/e head face gasket, but not everyone knows.
Just tested the gasket with tissue tapped to a screwdriver and went all the way round, and couldn't find any leaks, will wait till it's cooled down then try soapy water around it see if I can see it bubbling though .
Quote from: 2000mr2 on April 2, 2023, 08:09Just tested the gasket with tissue tapped to a screwdriver and went all the way round, and couldn't find any leaks, will wait till it's cooled down then try soapy water around it see if I can see it bubbling though .
That is a test for ambient temperature gas pressure leaks but I believe the water will boil at exhaust gas temps and give unwanted bubbles.
Quote from: Joesson on April 2, 2023, 09:02That is a test for ambient temperature gas pressure leaks but I believe the water will boil at exhaust gas temps and give unwanted bubbles.
Oh, is there any other way to test it then ?
Quote from: 2000mr2 on April 2, 2023, 09:05Oh, is there any other way to test it then ?
There may be some, likely costly, gadget for such a test but on a wet Sunday in Lincolnshire
@Carolyn 's flappy paper stick is the gold standard.
Not a recommendation. Just alternatives.
https://youtu.be/9CPqbaSgcok
https://youtu.be/zMok2y05jNE
I have put the oe manifold gasket on now the 02 sensors are reading right it goes from rich to lean like it should a lot better than before but I'm still get engine codes saying bank 1 and 2 are rich.
I also looked for air leaks by the method above and couldn't find anything.
I'll try fuel pressure next
Quote from: 2000mr2 on April 1, 2023, 18:42U know any places that sell them that are cheep that are good.
I got eBay ones but they say there denso and that there oem
I have a set of OEM injectors - I can lend them to you to try out.
PM me your address andf I will pop them in then post for you.
As a handy ref. the areas to investigate are
Injector leak, blockage
Mass air flow meter
Engine coolant temp. sensor
Ignition system
Fuel pressure
Gas leakage on exhaust system
Open or short in heated oxygen sensor (bank 1, sensor 1)
circuit
Heated oxygen sensor (bank 1, sensor 1)
ECM
Quote from: 2000mr2 on April 1, 2023, 18:42U know any places that sell them that are cheep that are good.
I got eBay ones but they say there denso and that there oem
Didn't somebody on here buy Denso injectors from ebay to find out they were fake??
I knew I read it somewhere.. see below.
Not a plea for help, but a warning and help for others.
I couldn't find my 1zz-fe original injectors, I spent so many hours looking for them. Gave up hope so bought another set on ebay. Lots of quite expensive second hand dirty grim ones, but spotted full sets of new ones for £32 to £50 on ebay and amazong etc. All listed as 23250-22040 Denso OEM injectors. Bought them, delivered in 2 days... laughing!
I fitted them not paying too much attention - they are green they say denso etc.
After a drive I thought it was running a bit rich, the smell gives it away, rougher tick over too. Then on a long cruise got the engine warning light with a fault code for being too rich:-
P0172 System too Rich (Fuel Trim) (Bank 1)
Looking at the fuel trims, they were maxing out the negatives... -25% etc.... and still the lamda was up at 0.95 0.98 etc..... we are running massively rich and the ECU cannot lean it out enough.
Thought I might have knocked the MAF so swapped it with a spare... still the same.
After loads more digging I found my original Toyota Denso 23250-22040 !
Put them in, and the fuel trims dropped to normality. No more rich code etc.
SO BEWARE OF THESE CHINESE COPY FAKE INJECTORS! THEY HAVE NEVER SEEN A DENSO FACTORY - LOOK FOR THE CIRCLES ON THE SIDE FROM THE INJECTION MOULDING EJECTORS PINS. ALSO THE PART NUMBER AND DENSO LOGO IS ON THE WRONG SIDE AND THE NOZZLES LOOK DIFFERENT.
Orange seal and lighter green are the ebay fakes.
Good fuel trims with the original Toyota Denso injectors
Hope this helps someone in the future.
Yes beware of counterfeit more than ever. In the past you could tell because there were some obvious differences but over time they kept getting better but you can still tell because the original part looks like a copy and the knock off having a better finish.
Now the parts are nearly indistinguishable and you have to look hard for markings like micro laser etching that only the factory can do. You can forget about the holograms that are on the packaging because the Chinese have mastered that also.
It's not to say you can't get original parts from eBay and Amazon but you still never know because these days it's better to go directly to the dealership. Salvage parts have never let me down as a good alternative of saving money on original equipment parts.
Had this problem myself, running rich both banks.swapped injectors still didn't solve it so tried everything else and ended back at the injectors. Spent some proper money on a real set and problem solved. Most injectors you see in line are fake.
👍