Commodore won’t idle!

[charliesvx]

Hey guys
I’ve tried absolutely everything to fix my L67 vx but I’m all out of ideas… Everytime I cold start the car it shakes and shutters for about 5 seconds and then goes up to operating rpm but continues to misfire. I’ve replaced Spark plugs, leads, IAC valve, tightened the throttle cable and cleaned the maf sensor.

Just today I went to turn the car over and it starts but goes in between 200-300rpm and then stalls out I don’t think it’s a fuel related problem as the pressure is fine. It could potentially be coil packs as they haven’t been replaced by I highly doubt it as the engine sounds as though it’s choking (lacking air)

What are you guys thoughts…

 

[lout]

clean the throttle body
there are 2 iac valves, did you get the correct one
how many km
what crappy fuel do you use
when were O2 sensors changed

 

[charliesvx]

clean the throttle body
there are 2 iac valves, did you get the correct one
how many km
what crappy fuel do you use
when were O2 sensors changed

I changed the IAC valve that’s sitting ontop of the throttle body
it’s got 227xxx kms
I put 91 in it
And I only got the car a few months ago so not sure when O2s have been changed I’m assuming not for a while …

 

[lout]

each throttlebody has one iac , but there are two variants
re fuel, i also meant budget brands or name brands
always important to list that you bought car this way as opposed to new problem
it adds another 100 variables into the mix
remove tps and check little square adaptor is in place, many people lose these

 

[charliesvx]

each throttlebody has one iac , but there are two variants
re fuel, i also meant budget brands or name brands
always important to list that you bought car this way as opposed to new problem
it adds another 100 variables into the mix
remove tps and check little square adaptor is in place, many people lose these
View attachment 267207

Ahhh ok, yeah I only just made an account and didn’t realise that would be important to add… the rough idle has been a problem since I bought the car but only now has gotten much worse. I’ll check the tps now

 

[lout]

try turning ignition to reds for 5 seconds
then switch off, then attempt to start
this allows the fuel pump to prime
in case it is a fuel pump check valve problem
they should hold pressure for weeks
but sometimes they bleed down over a few hours

 

[charliesvx]

Hey man
I don’t want to say it’s not fuel pump but I’m fairly certain it isn’t. The pump primes Everytime I turn the key and I can’t hear any abnormal noises. I was able to start it this morning and push the gas down and held it at about 2000-2500 rpm for about 15 seconds and then let off and it idled but really low… not sure tbh man

 

[lout]

Hey man
I don’t want to say it’s not fuel pump but I’m fairly certain it isn’t. The pump primes Everytime I turn the key and I can’t hear any abnormal noises. I was able to start it this morning and push the gas down and held it at about 2000-2500 rpm for about 15 seconds and then let off and it idled but really low… not sure tbh man

ok , that kind of rules out fuel pump

 

[Lex]

ok , that kind of rules out fuel pump

Fuel filter?

I'd be checking the throttle body & iac.
The l'd be testing the dfi & coils?

 

[Fu Manchu]

I say it every time. Check for vacuum leaks. It’s so simple and easy. Cost is minimal other than making a smoker with a small air pump. Intake fills with smoke and smoke comes out of air leaks.

Tick off the list if it checks out ok.

Move on to next thing.