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

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.

morch_66479

ramrod

Doing basic maintenance before chasing your tail looking at the more complicated things always pays dividends

The new distributor cap, rotor button, ignition leads and spark plugs, with a throttle body service will fix most if not all of your problems

The rotor button is held on by friction. To remove it pull it upwards, since it's been many years since it was changed (if ever) some force may be needed

As for the throttle body gasket I can post it out to you

morch_66479

ramrod
Doing basic maintenance before chasing your tail looking at the more complicated things always pays dividends
The new distributor cap, rotor button, ignition leads and spark plugs, with a throttle body service will fix most if not all of your problems
The rotor button is held on by friction. To remove it pull it upwards, since it's been many years since it was changed (if ever) some force may be needed
As for the throttle body gasket I can post it out to you

Yeah, I'm trying to go back to basics but at the same time i know it runs perfectly fine for a couple of minutes when i fire it up so if the basics were stuffed it wouldn't run at all i guess?

I used a fair bit of force prying underneath the rotor but no go, may need to go harder!!

I might call Berry Motor Group tomorrow and see what they got, I'll replace the leads and might even try borrow an IAC, TPS & AFM just to carry out some swapnostics.

carnut222

I have a decent set of new plug wires if you need them and want to come up this way.

carnut222

morch_66479
https://ozvolvo.org/discussion/comment/191246#Comment_191246
Yeah, i"m kinda trying to go back to basics but at the same time i know it runs perfectly fine for a couple of minutes when i fire it up so if the basics were stuffed it wouldn't run at all i guess.
I used a fair bit of force prying underneath the rotor with a screwdriver but no go, may need to go harder!!
I might call Berry motor Group tomorrow and see what they got, I'll replace the leads and might even try borrow an IAC, TPS & AFM just to carry out some swapnostics.

Maybe also borrow an ECU? Hopefully it’ll be something crazy simple! Maybe there’s a potato jammed up your tailpipe? ;)

morch_66479

I'm going to visit Berry Motor Group after work and get a few bits:

New spark leadsECUSensors

Hopefully one of these will help me resolve the issue!

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