LH2.4 B230f Idle Issue - fixed again!!

morch_66479 · 2021-05-16T00:14:28+00:00

For LH2.4, the throttle position switch adjustment is critical. If the switch is misadjusted, the ECU doesn’t know it’s meant to control the idle speed, so i...

morch_66479

carnut222
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.

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.

carnut222

morch_66479
https://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?)

morch_66479

timbo
Have you cleaned the throttle body?

No i haven't actually, worth a shot?

timbo

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.

morch_66479

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.

timbo

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?

morch_66479

timbo
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?

I couldn't find any fault codes from my checks last night but i may need to double check this.

Major Ledfoot

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

morch_66479

Major Ledfoot
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

Yeah, i find this strange also, i double checked it and it's definitely a 3-3-2 but it ain't listed :-(

timbo

@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

morch_66479

timbo
@bgpzfm142 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

But 3-3-2 isn't even listed as a code for the full throttle test, there's no information on what 3-3-2.

I could be chasing my tail here though..

ramrod

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

carnut222

ramrod
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

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??

Major Ledfoot

(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.

timbo

morch_66479

timbo
https://cdn.ozvolvo.org/uploads/723/QM3GIG1G3O58.png

Sorry, I edited my code message on Page.1

It gave me codes 3-3-2 for both idle and open throttle but it should have been 3-3-3 for wide open throttle.

morch_66479

UPDATE:

The car will run when i apply throttle as it's about to die.

Over 6 months ago it's had a new fuel pump relay and fuel filters installed.

Checklist for when i get home tonight:

Check fuses for overheating and check voltages. (all fuses are intact)Apply 12v directly to the IAC when it starts to hesitate to see whether it comes back to lifeRe-check diagnostic codesTry find proper diagnostic process for checking the MAF & TPSClean the throttle body as this would be no harm to do anyway, {"mention":{"name":"ramrod","userID":2359}} where are you based so i can grab a gasket?

ramrod

Sydney

I can post one out to you

ramrod

There is no conclusive test for the air mass meter, other than to fit one that is known to work

morch_66479

UPDATE:

I put 12v directly to the IAC and it didn't do anything different. Starts, runs and cut out as usual after a minute or so.Checked battery voltages and fuses for overheating and they're all good. Have 12.3v with engine off and 13.6v when running.Also lifted the rear seat and put my ear against the carpet. I can hear the fuel pump buzzing as normal and then stops once the engine stopsDiagnostic codes were corrected on Page 1 - still can't find relevant code for wide open throttle code 3-3-2I replaced the distribution cap as one connection on the old cap was badly corroded, i could not remove the rotor though. How does it come off?I will need to get a new gasket before cleaning the throttle bodyAlso when i rev it to prevent it from cutting out its very lumpy and not smooth.

« Previous Page Next Page »