Having issues with high idle 4g94
Hey guys I just bought a 2002 Parjero iO last week. I was looking online for some info and came across the forum, started reading and signed up. There is some great info on here! My iO is a 5 door, automatic transmission, 4g94 engine (I think it’s MPI) and has 90000 km. It had been sitting for about 6 months before I bought it and needs a little TLC. She’s drivable but I’m trying to get her tuned up. Right now I’m getting pretty bad fuel economy. So far I have changed the oil, coolant, and air filter. There a little hesitation when I first start pushing the gas pedal but after that it’s fine. (Probably need to change the plugs but haven’t gotten to that yet. Any suggestions on plugs btw?) Also I cleaned the throttle body but I am having an issue with high idle. I have checked for a vacuum leak but can’t find one. When I start it from a cold start idle is 1500 and within a minute or less is at 2000 and stays there. If I leave it in park and turn on the AC to high the rpms drop to about 1500. With no accessories on I put it in gear with my foot on the brake then rpms drop to 1000-1100. Also I noticed that sometimes when I am costing at maybe 20 km/h or less with foot barely on the pedal or not on the pedal the rpms with fluctuate between 1000-1500. It will go up to 1500 then drop back to 1000 then repeat in about 1-2 second intervals. Any ideas of what I could check? It is difficult and expensive to get parts here so any help would be greatly appreciated. Thanks.
plug
I fitted the NGK iridium on mine, same engine as yours and I was very happy with them, the ref could be NGK iridium BKR5EIX-11 but check the reference before ordering. They are a bit more expensive but will last longer and I found that the engine run a bit better. (could have been because of the plug being new!)
NGK have always been my choice of plug, iridium or other.
Happy io
Plugs
Just picked up those plugs (5464) ngk bkr5eix-11. They are the same plugs BOB_OZ mentioned in another thread.
This might be a dumb question but do I need to adjust the gap before I install them or do they come at the right gap? If gap needs to be adjusted what should it be. Thanks.
plug gap
Just picked up those plugs (5464) ngk bkr5eix-11. They are the same plugs BOB_OZ mentioned in another thread. This might be a dumb question but do I need to adjust the gap before I install them or do they come at the right gap? If gap needs to be adjusted what should it be. Thanks.
Never adjust the gap on any iridium plug...no such thing as a dumb question !
Happy io
IAC value cleaning
Thanks. I went ahead and pulled off the throttle body this afternoon to give it a real good through cleaning. I also took out the IAC value and cleaned it. Put everything back together with high hopes but still exactly the same. Idle is still sitting at 2000 in park and 1000 in gear. Any other thoughts on what it might be? Appreciate the help.
Idle control valve
I have issues similar with my mpi however currently they are on the low side.
I've found that the air intake for the IAC is on the low side of the air horn and i tend to collect oil and debris in there - it also can clog with liquid cleaner etc.
Cleaning the MAF sensor with the correct cleaner and running a good tank treatment is the best bet - the IAC die around 280,000kms so mine is likely on the way out (320,000kms)
Also the o-ring on the IAC can get debris on it and not seal if you are not careful.
If you were in brisbane i'd offer to swap IAC's and see how yours behaves
IAC value
Thanks for the offer but since I'm on a small island in the Caribbean that would not be possible at all. I do have a friend here though that has an iO with a blown motor. I'm not sure if it's a 4g93 or 4g94. I think it's MPI because I don't remember seeing any GDI badging. Do you know if those IAC values are the same on both engines? Are they the same MPI and GDI?
I did pull out the IAC value and turn the ignition to the on position and the value does vibrate for a second. I know that's not a definitive answer to whether or not it is functioning properly but a least something is happening. I might have to try and find a multimeter somewhere and test it.
I will try out the other things you mentioned as well. Thanks a lot!
GDI engines don't have an IAC valve.
The GDI engines are "drive-by-wire" - there is no throttle cable linking the accelerator pedal to the throttle body, the connection is electrical and the ECU simply adjusts the throttle plate to set whatever idle rpm is required.
High idle update.
Just a quick update. I went over to my friends house this afternoon to take a look at his iO. It has a 4g93 MPI. Mine is a 4g94 MPI. I could not tell if the sensors were exactly the same but they look exactly the same. So I tried them one at a time. First I tried his IAC value but my idle was still at 2000. Then tried his MAF sensor but idle still at 2000. Then tried his Throttle Control sensor but still at 2000. Each time I tried a part I took it back off and put on my original part before trying the next sensor. So end of it all nothing helped it still functioned the same each time. Not to say that I know for sure that his sensors were all in good working order I don't know that for sure. Do you guys have any other thoughts? Thanks.
A vacuum leak ...
I know you say you've checked - two possible places that are hard to detect are the brake booster and the PCV valve - the hoses can be removed and capped with your thumb for test purposes. There should also be a couple of small diameter (abouth 1/8" ID) rubber hoses, one for the front freewheel mechanism, and at least one more for the charcoal canister purge system - again, these can be capped for test purposes
Vacuum leak
I know you say you've checked - two possible places that are hard to detect are the brake booster and the PCV valve - the hoses can be removed and capped with your thumb for test purposes. There should also be a couple of small diameter (abouth 1/8" ID) rubber hoses, one for the front freewheel mechanism, and at least one more for the charcoal canister purge system - again, these can be capped for test purposes
I had vacuum leak issues and the symptoms are exactly the opposite. Unmetered air into the system caused poor fuel mix thus low idle-almost stall. Spreying on the engine to find the leak raised momentarily the idle.
For you to find the solution you must identify if you are on open or closed loop fuel control first. If the symptom is on closed loop you might check your lamda (oxygen) sensors
How large a leak did you have?
I had vacuum leak issues and the symptoms are exactly the opposite. Unmetered air into the system caused poor fuel mix thus low idle-almost stall. Spreying on the engine to find the leak raised momentarily the idle.
In most cases, vacuum leaks on EFI equipped vehicles will cause high idle speeds - open loop idle should occur only after a cold start - at which time the engine management system should be already holding the idle speed high and the mixture rich enough that it does not stall, once the engine reaches operating temperatures the system should switch to closed loop at which point the fueling is determined based on the O2 (lambda) sensor, and the system should detect and compensate for the unburned oxygen in the exhaust by adding fuel - more air + more fuel = more rpm.
idle
May be a silly idea but could it be the cable that connect to the gear box not adjusted properly ? or the accelerator cable under too much tension somewhere ?
It maybe a good idea to try disconnecting them at the engine side and see what happen ....
Not sure...just trying to give some idea !
Happy io
Syndicate
Before we can offer any sort of reasonable advice...
we first need to know what we're dealing with - the 4G94 in the Pajero came in both MPI (multi-point-injection) and GDI (gasoline-direct-injection) - two very different technologies.
Do you see any GDI badges on the outside of the vehicle? Is there a GDI light on the dash? Is there a big plastic cover with the word GDI on it over the engine? Can you see the ignition coils on top of the engine - are there two coils or four?