HELP!! Au xr8 series 1 Running rough,

[keshin]

hey guys in need of some help here,
i have an au xr8 manual, a week ago i was on a cruise and she was running fine as it has since i have owned it (over a year)
later that day i turned it off for about 10 mins then when i started it and got back onto the road it started running rough, backfiring through air box, (feels like missing)
I have ordered an elm327 to see if any fault codes are showing but it probably wont arrive until tomorrow
Car has done about 210000 k's
since having it at home it seems to rougher on idle than it did when it started playing up.

Notes:
*i have replaced the fuel filter since this happened
*air filter is not very old and clean
*i pulled maf sensor out and it looked clean (no corrosion or brown color)
*the car had new cats fitted about 6 months ago
*i have never run the car dry (out of fuel) but have had it low
*the camshaft syncronizer has not developed any squeaks or noises
*I have unplugged the ISC and the car still ran until i gave it a little rev then it died out
*the plugs, leads, coil pack do not appear to have been replaced ever
*the exhaust seems to sound alot more crackly and has some higher pitched popping noises
*i have run the car in the dark and cannot see and sparks etc. from the leads.

Im after suggestion from anyone who has any idea what is causing this, i would prefer not to go replacing spark plugs, leads, coils, pumps etc unless i am pretty certain that is the problem. I am out of work so funds obviously are a little tight at present.
Thank you guys in advance

[keshin]

just took car for a drive after fiddling with a few things, symptoms are as followed:

When driving through all gears from 0% throttle to about a 1/4 4 throttle it seems to miss a lil or at least thats how it feels. kind of like a splutter and hesitates only during initial load of each gear.

just noticed when braking to a stop the oil pressure drops to 0 then works back up

no longer backfiring

[macman]

Pre-warning: I am no expert and have asked my own fair share of stupid questions recently but I'll make some comments here as no one else has (yet).

Tempted to say that unless the car is using (burning) oil or leaking oil that the oil pressure gauge thing might be an independent and unrelated issue? Could be down to a bad connection or a voltage problem? You say when braking the gauge drops - bad earth somewhere? Here comes the stupid bit: do the brakelights work? Is there a correlation?

210,000k's with original Motorcraft plugs and leads isn't great. That said, I bought my TE50 at 215,000k's and it still had original plugs and leads too. I replaced them soon after, coil packs too.

I've recently replaced my second round of plugs as it seems they were compounding my problems and causing some issues (pinging). The plugs were "only" 40,000k's old this time but general consensus said this was still too long to leave plugs for.

I know you said you don't want to touch the plugs if it's not confirmed to be the issue but I'd have to recommend you take out the plugs and have a look. Plugs (standard, not platinum or iridium) are not expensive, less than $6 each I paid for NGK BPR6EF's just last week at SuperCheap Auto. The condition of the plugs might tell you a story as well.

You only need a plug socket, preferably one you can put a spanner onto (rather than a ratchet only type plug socket).

Hopefully you can get that ELM327 up and running soon.

[keshin]

thanks mate, oil issue is sorted was a loose wire (duh) anyway, i was cautious about plugs as i was under the impression we shouldnt run anything other than iridium in them, if im mistaken then i will gladly go buy some new plugs now lol
thank you for commenting, its driving me mental, hopefully this elm327 gets here soon so i can pull these codes

[keshin]

well bugger me, pulled the plugs and dammmmn id say they need replacing lol, on a side note tho, will this cause it to play up immediately eg turning car off then starting again

these are NGK iridium tr55ix at 211xxx
i also smelt each one upon removal and had barely any noticeable fuel smell

[keshin]

i should note i just did a ohms test on the plugs and all came out at about 4200ohms, on a high ohms test they all came back at 0, according to a spark plug testing thing 5k ohms (plus minus 1k) is good, so by that this means they are not buggered (yes the electrode is pretty much cactus)

so my question is now, would just spark plug gap cause my issues of what feels like the engine is missing and spluttering

[xrxystu]

If you're worried that the centre electrode looks tiny and suspecting they're worn away, that's not the case.
Iridium plugs have a very small diameter "precious metal" electrode.

They are kinda dirty though...

Stu

[keshin]

ok guys got an update just so if anyone runs into this problem its here,
first up i was wrong about plugs, leads, they tested well within specs, however i have replaced the plugs regardless,

Now my ELM327 arrived today and i have run tests and the results are as follows:
diagnostics code PCM0116 fault code (points to temp sender, however this is not faulty)

live data streaming shows CMP_F Fault Yes (points to camshaft position sensor is faulty)

now before i fork out $300 on a new CMP i am getting my mate whos xr8 has a faulty CMP and we have not replaced it yet, so i will run the same tests on his and hopefully we get the same result.

I will update when i am sure this is the problem.
Note: i have no squeals or noises from the CMP which is why i am hesitant as all reports of failure of the CMP i have heard resulted in squeaking/squealing

[keshin]

ok guys i cant seem to delete my last comment and it is wrong, after more research and watching the live data i will post a video and hopefully someone can work out whats going on, appears its running lean according to the oxygen sensors

[macman]

Yeah those plugs don't seem overly bad. Maybe just carbon fouled and overdue being changed out. Are they "sooty" or are they oily? They look sooty to me. I'm under the impression a fouled plug can cause misfiring.

I don't know much about iridium plugs but I do know the electrode is supposed to be smaller than a standard plug so the tiny electrode seems normal, as "xrxystu" said above. I don't know however if that gap is normal for an iridium plug. My standard plugs are gapped to 1.1mm and those iridium's look a lot more than 1.1mm (Ford w/shop manual says 1.3mm for 5.0L from memory). An oversized gap can cause misfiring and extra strain on the ignition system (coils). I suspect on that theory a gap too big combined with original (old) coils could well cause the problems. In my opinion and in theory. Maybe see if you can confirm what the gap should be for an iridium plug and see what those old ones measure at.

As for the camshaft position sensor and synchroniser. Just because it's not squealing or whining doesn't mean it's not faulty. The sensor can be faulty without the bearing being dry and the bearing can be dry without the sensor being faulty. It's unlikely there'd be any buildup/dirt on the sensor but wouldn't take a moment to whip the cap off and look.

Sorry for the dumb question but is "CMP" actually the camshaft position sensor, (or the camshaft synchroniser)? Or is it the crank angle sensor, down near the harmonic balancer?

I look forward to seeing the live data. Something I haven't tried with my AU yet.

[keshin]

ok guys heres a video of what its showing me.
also i am getting error codes p0116 and p0507
EDIT: I should mention these codes are only coming up on the "key on engine on test" i have no codes in the DTC
hopefully someone can shed some light for me as its starting to drive me crazy

https://www.youtube.com/watch?v=ehmgTW3nLBY

[keshin]

Originally Posted by macman

Yeah those plugs don't seem overly bad. Maybe just carbon fouled and overdue being changed out. Are they "sooty" or are they oily? They look sooty to me. I'm under the impression a fouled plug can cause misfiring.

I don't know much about iridium plugs but I do know the electrode is supposed to be smaller than a standard plug so the tiny electrode seems normal, as "xrxystu" said above. I don't know however if that gap is normal for an iridium plug. My standard plugs are gapped to 1.1mm and those iridium's look a lot more than 1.1mm (Ford w/shop manual says 1.3mm for 5.0L from memory). An oversized gap can cause misfiring and extra strain on the ignition system (coils). I suspect on that theory a gap too big combined with original (old) coils could well cause the problems. In my opinion and in theory. Maybe see if you can confirm what the gap should be for an iridium plug and see what those old ones measure at.

As for the camshaft position sensor and synchroniser. Just because it's not squealing or whining doesn't mean it's not faulty. The sensor can be faulty without the bearing being dry and the bearing can be dry without the sensor being faulty. It's unlikely there'd be any buildup/dirt on the sensor but wouldn't take a moment to whip the cap off and look.

Sorry for the dumb question but is "CMP" actually the camshaft position sensor, (or the camshaft synchroniser)? Or is it the crank angle sensor, down near the harmonic balancer?

I look forward to seeing the live data. Something I haven't tried with my AU yet.

CMP is camshaft position sensor, i believe that to be also known as camshaft syncronizer (i may be wrong)

[macman]

Originally Posted by keshin

CMP is camshaft position sensor, i believe that to be also known as camshaft syncronizer (i may be wrong)

That's cool. I wasn't sure, just wanted to confirm we're talking about the same thing (we are).

EDIT: what did the 'static' diagnosis tell you? I mean, with engine off but ignition switched ON did you get any sensor failure codes? Just out of interest.

[Evgeni]

I use these guys for sensors. Lists an Au v8 cam sensor for $79.
http://www.cyberspaceautoparts.com.a...le_Sensor.html

Just some initial thoughts with the video.

TPS voltage is a little high. May point to a previous adjustment. Might explain the 507 code.

Most of the video is of the system in open loop. Can you ask Forscan to display long term fuel trims for both banks. Once the system drops into closed loop, bank 2 (drivers side?) is running alot richer.

[keshin]

ok ill run it again with the long term in replacement of the short term, and particular amount of time i should run the car/record for

EDIT: also i haven't adjusted anything yet, will need to find a walkthrough on doing it as this is my first time working with fuel injected cars (always worked on carby)

[Evgeni]

Please keep short term in - get rid of something else.

Short term is the PCM's response to the o2 sensors. The long term trim adjusts to keep the short terms as close to 0 as possible to give it the maximum range of adjustment. It would be good to get this picture.

Rather than running the car for a period of time, one of the codes (116) points to a coolant temp sensor issue. The range for a sensor working off reference voltage is 0 to 5v. It would be good to get a reading when the car is cold and then again when you are at operating temp and see what voltage reading the coolant temp sensor (ECT) is giving.

[keshin]

alrighty i think i got it, i have set it up to show both long and short term fuels, the car has been off for about an hour ill leave it sit another hour (coolant isnt hot enough to burn at the moment) then i will do a recording of it from cold, then ill add the second recording of it at operating temp (just to be certain, how long should i run it to get to operating temp)

Thank you heaps for your patience im sure half the questions im asking are basic ones lol

[keshin]

another question, i just pulled the motorcraft coil packs out and did a ohms reading on them and got 1.6 - 2.2 throughout,
Is there anychance somone would be able to test theirs or know if this is within spec? i cannot seem to find any spec sheets on these. Thanks

EDIT:
I have just removed the CMP Top and this is what it looks like.
I dont suppose these a cleanable are they?



ok that was another stupid question....................wiped with a rag and its all clean now.... sorry guys just having one of those days

[macman]

That sensor looks like poop. I figured it could be dirty but didn't really expect it... Looks like rust staining? And some metal filings stuck to it? That can't give a great signal.

Depending on what that buildup is and how easily it comes off, I'd be using a toothbrush or a brass wire brush or maybe just a rag with some WD40 to clean that up.

EDIT: while you've got the sync cap off, I'd personally drop a little engine oil down the shaft too just to keep the bearing oiled (to prevent the squeal).

[keshin]

Originally Posted by macman

That sensor looks like poop. I figured it could be dirty but didn't really expect it... Looks like rust staining? And some metal filings stuck to it? That can't give a great signal.

Depending on what that buildup is and how easily it comes off, I'd be using a toothbrush or a brass wire brush or maybe just a rag with some WD40 to clean that up.

EDIT: while you've got the sync cap off, I'd personally drop a little engine oil down the shaft too just to keep the bearing oiled (to prevent the squeal).

thanks mate, i simply wiped it with a rag and it came up clean as, inside the CMP was clean as not a stain or mark on it, i already have it back together but once later on i will do that. great thinking

I am currently uploading the cold run video, will wait until i get comments before i try a operating temp one as something weird happened i think so ill await comments once i upload it

[keshin]

Ok guys heres the video, for some reason it didn't display anything in the long term fuel,

https://www.youtube.com/watch?v=hobcRBb-fa8

Is it just me or doe's it seem im losing fuel pressure ?

[keshin]

guys just done another key on engine on test new codes

all are Module: Powertrain control module

p0116- suspect sensor
p0172- HO2s sensor mixture constantly lean
p0175- system too rich bank 2
p0507- IAC valve duty cycle higher than expected

[keshin]

anyone know what this hole is, its open not blocked

also iv read that a faulty temp sender can cause these problems for the 2 new codes i got. is this accurate?

[keshin]

pulled maf sensor out, i don't know if you can see but the shorter one does have a little white buildup on it, would this cause issues?

[Evgeni]

Thanks for posting the vid.
Your cam sensor looks ok. Usually what happens is the resistance in the sensor and wiring increases and this is what registers the low cam signal. They are pretty resilient as the computer is looking for a high low electrical signal. The sensor actual outputs a analogue sine wave that gets interpreted by the pcm and only the peaks and troughs register. Unplug the sensor and get a voltage reading from the harness with the key on. This will tell you that the computer is providing a bias and the low signal is most likely a result of the sensor and not the harness.

Re: checking ignition coils and leads. Ignition systems draw about 7 to 8 amps. When you test resistance with a multimeter, it sends something in the ballpark of 100 milli amps from one lead and looks for it on the other. It can give a false reading. Something that can carry a small current, may not be the case when the current is increased 800 times. Without special equipment, the easiest way to test is to connect a test light to a ground point (preferably not the battery in this case) and pull off a lead. Hold the lead near the test light to give the spark somewhere to go and gradually pull the lead away to see how far the spark can jump. You want about 20mm.

One of the possible reasons why long term is not registering is that the majority of the video the car is in open loop. The worrying signs don't show until the car drops into closed loop. The o2 on bank 2 is reading rich and short term is taking away up to 40% of the fuel delivery, and the long term is not correcting.
First thing you should probably do is confirm the o2 signal. Pull a vacuum line and see if the o2 sensors drop in voltage towards 0.1v. If this is the case, it will tell you that the system is running rich and it is not a case of a false reading. I wouldn't worry about the IAC count until this is resolved as it is only happening on the one bank.

You are not losing fuel pressure. That parameter looks like injector pulse width. I'm not aware of a pressure sensor for the fuel system, or at least one that is digital.

Coolant temp sensor was a little over 2 volts with it at 35 degrees?. Scale is 0 to 5v, so try and keep a track of what temps give what readings and this will tell you what kind of scale and range the car is working off. Unlikely that the reference voltage is dropping and likely that resistance in the sensor is increasing. The 5v will be shared, so use a diagram, find what sensor the ECT shares reference voltage with and you can measure it from a sensor that is easy to get to.

[Evgeni]

A dirty MAF can cause problems, but you only have one MAF and the problem is on one bank. The MAF is not looking like a suspect at the moment.

[keshin]

thank you, i just tested the vacuum while running and the car only just kept running and the o2 sensor that was varying all over the place stabalized at 1-1.1v

Voltage going to Cam sensor is 9.44v

[Evgeni]

Just watched the vid again.
When the system is in open loop the bank 1 o2 sensor looks like it is switching.
It shouldn't be doing this in open loop. Switching is done by the pcm via the injectors. The o2 simply reads what is in the exhaust.
Problem may be with the bank 1 sensor if it is giving a false reading. Strange to have one bank go rich - you would think leaking injectors if this is the case.

[Evgeni]

Originally Posted by keshin

thank you, i just tested the vacuum while running and the car only just kept running and the o2 sensor that was varying all over the place stabalized at 1-1.1v

Voltage going to Cam sensor is 9.44v

Input to cam sensor is fine.

O2 sensors are suspect. You are adding air and the system is reading rich. Was this in open loop or closed? Just want to make sure that the computer didn't try to correct the leak you created.
If it was open, then things dont read right. How big was the leak you created? What happens when you create a big leak, like pulling off the brake booster? If it still reads rich, there is either an o2 sensor issue or a wiring problem eg o2 signal shorted to power on the heater circuit. Computer would be doing well to correct a massive air leak to make the o2 read rich.

[keshin]

ill record another video for you so you can see what it does (you should also hear the sound when i remove the pipe so you will know when i have removed it) , im only just understanding most of this, again thanks heaps for your patience and helping me