You say the idle is good for a minute. Is this consistent every time or intermittent?
What is the idle speed when the idle is satisfactory? How does the engine drive otherwise? Is this problem occuring at hot or cold temperature or both? What happens if your keep the idle speed up slightly? Do you have a video of it stalling?
carnut222https://ozvolvo.org/discussion/comment/191115#Comment_191115
Hmm, not sure what the computer sees when you disconnect the throttle sensor - probably goes out of idle control mode so it should put the IAC into a default part open setting. There is a procedure to test the throttle sensor...There are 3 pins IIRC, one should be earthed through the harness, and when the throttle is closed it should provide continuity to the other pin via earth, and at full throttle it should earth the other pin. Basically two normally open microswitches, one closes when throttle is closed, and one closes when throttle is fully open. I suggest checking out the Greenbook manual relevant to the idle adjustment procedure...there’s some info here that may be useful:
http://www.turbobricks.com/forums/showthread.php?t=321181
I doubt if it’s the MAF if the car runs fine off idle. Sounds like your base idle may be set a bit too low...try the procedure in the link above and see how you go.
Followed this procedure and all is within spec ?
ramrodYou say the idle is good for a minute. Is this consistent every time or intermittent?
What is the idle speed when the idle is satisfactory? How does the engine drive otherwise? Is this problem occuring at hot or cold temperature or both? What happens if your keep the idle speed up slightly? Do you have a video of it stalling?
Everytime since this started yesterday afternoon. Temperature doesn't change the effect. To keep it running I need to keep the revs over the ~2,000rpm
When it idles satisfactory its how it always was which looks to be at 850rpm on the dial.
Here's a clip of it doing its little dance!
https://youtu.be/Y3P4JyvnvGI
morch_66479https://ozvolvo.org/discussion/comment/191118#Comment_191118
Everytime since this started yesterday afternoon. Temperature doesn't change the effect. To keep it running I need to keep the revs over the ~2,000rpm
When it idles satisfactory its how it always was which looks to be at 850rpm on the dial.
Here's a clip of it doing its little dance!
https://youtu.be/Y3P4JyvnvGI
Wow, that’s pretty strange...not sure what to say???
PS I figured out what to say - drop it off at my place and I’ll dismember it and sell the bits LOL!
Just gonna check the diagnostic codes now and see what it has to say.
I'll get back to you
Haha, I'll need to be careful next time I visit. Wouldn't want you sneaking parts off it when I'm not looking ?
I have a fuel pressure gauge set-up to use on these...may be worth looking at that. Is the fuel level low, medium or high? Maybe feel the fuel pump fuses and see if they’re getting hot? Just thinking out loud.
I followed a YT clip on how to check diagnostics codes and mainly focused on this part where he checked the open and closed positions of the TPS.
https://youtu.be/odE9LoTQqwg?t=238
For the full throttle circuit i got a code of 3-3-2 when it should be 3-3-3
For the idle circuit i got 3-3-2 which tells me its ok in the idle position.
Are these accurate codes to go off or am I going down the wrong road?
carnut222I have a fuel pressure gauge set-up to use on these...may be worth looking at that. Is the fuel level low, medium or high? Maybe feel the fuel pump fuses and see if they’re getting hot? Just thinking out loud.
Like a gauge that goes up on the rail?
It's 2/3 full and has the new fuel pump relay installed as i encountered that not starting issue a while back. I'll have a check of the fuses later on.
morch_66479https://ozvolvo.org/discussion/comment/191127#Comment_191127
Like a gauge that goes up on the rail?
It's 2/3 full and has the new fuel pump relay installed as i encountered that not starting issue a while back. I'll have a check of the fuses later on.
Yep, I have cut up a spare fuel rail and made it into an adapter with a fuel pressure gauge so it can bolt between the rail and the input hose. The reason I was asking about fuel pump fuses (and maybe also check the relay) is it almost seems to be running out of fuel...I was wondering whether there’s something going on with the pumps and/or electrical supply to the pumps. Advise again, can you drive the car fine if you’re able to keep the revs up? Battery is OK and battery voltage check (not something odd going on with alternator causing voltage spike/drop?)
timboHave you cleaned the throttle body?
No i haven't actually, worth a shot?
Definitely worth a shot, If there's enough of an oil/carbon film on the throttle body it can cause low idle,and throw the fuel trims off. It's pretty common issue on redblocks and high km whiteblocks.i
It will be pretty obvious if that's your issue if you pop the hose off and have a look. If it's particularly dirty it's easier to remove it and give it a good clean but be careful not to split the gasket if you don't have a spare.
I did notice oil in the accordion pipe coming from the airbox but not sure if that's been there the entire time. I didn't worry it today.
I'm a little lost as to what else i could do with this now, I'm slowly running out of options and i can't find the meaning of the 3-3-2 code during my TPS diagnosis test.
I wouldn't worry about that self diagnostic test result at the moment.
Does it have any fault codes stored in fuel or ignition ecu?
timboI wouldn't worry about that self diagnostic test result at the moment.
Does it have any fault codes stored in fuel or ignition ecu?
I couldn't find any fault codes from my checks last night but i may need to double check this.
3-3-2 doesn't look like it's a legit LH2.4 code. See list of codes at URL below.
https://www.volvoclub.org.uk/faq/EngineOBDCodes.html
@Major Ledfoot it's a seperate self test that's detailed in the video that @morch_66479 posted earlier, not the regular one press fault code readout
You need to clean the throttle body
If it is half blocked which it will be if you haven't recently cleaned it, it won't want to run at idle. You need to remove it, buy a can of carb cleaner and a toothbrush, get it clean enough to eat from (surgically clean), spray the carb cleaner nozzle through the two vacuum line ports and verify the fluid sprays out of the tiny holes in the body near the butterfly valve
I have new throttle body gaskets
ramrodYou need to clean the throttle body
If it is half blocked which it will be if you haven't recently cleaned it, it won't want to run at idle. You need to remove it, buy a can of carb cleaner and a toothbrush, get it clean enough to eat from (surgically clean), spray the carb cleaner nozzle through the two vacuum line ports and verify the fluid sprays out of the tiny holes in the body near the butterfly valve
I have new throttle body gaskets
Yes, but if you watch his video, it seems to run fine for about a minute, then it starts surging then it dies...methinks something else is going on...almost as if the fuel is cutting out, or maybe a component (power stage? Fuel pump relay?) is overheating and causing a failure. I’m just speculating...if it runs fine when he applies throttle, then we need to consider other things. Could even be something like crud in the fuel tank...runs fine for a while then as the crud gets sucked towards the pick-up screen, it blocks fuel flow and dies? Really depends on whether he can get the car to run with application of throttle as it starts to die, as if that’s the case then it’s prob not something fuel related??
(this is me clutching at straws)
Are there any holes in the convoluted tube between the AMM and the throttle body? A crack or wear hole caused by that hose rubbing on another hose due to engine movement over many miles is a known issue. (It looks like it's rubbing on one of the aircon hoses in the video). If there's a hole in that tube, it throws off the actual air flow reading from the AMM, since the engine's sucking extra air through the hole which hasn't passed through the AMM.
I may be wrong, but it looks to me like the car is stalling as the ECU transitions away from relying on the IAC for cold start and and warmup and switching over to running temperature mode.
