Idle an timing adjustment.

[Beowulf.50Ram]

Ok so I have a 90 2.4l F.I model an I can't seem to find the correct adjustment for the idle screw. I know on old carbs it's 1.5 turns in then adjust from there. So is there a starting point for the idle set screw so that I can go from there an then set my timing? Thanks in advance.

[geezer101]

You shouldn't need to adjust the throttle stop at all unless somebody has already messed with it (I would check the throttle cable for slack and adjust it though, you'd be surprised how much a cable can stretch over the years). Being FI you will need to put the ECU into diagnostic/tune mode by grounding out the connection in the engine bay and resetting the distributor for base timing. If you adjust the distributor without grounding the connection the ECU will ignore the changes you make and you'll be stuck where you are now. I have recommended 'dynamically tuning' on a number of other posts. It's simply a matter of holding the engine @ 2,000 rpm and gently 'swinging' the distributor back and forth until you find a sweet spot that causes rpm to jump by themselves, then dialling it back a touch to compensate for lack of load on the engine. You should find an improvement in engine response out on the road and depending on how far out of tune it was prior to adjusting, maybe a chunk of hidden HP.

[Beowulf.50Ram]

My friends father replace the timing chain and they timed it incorrectly I believe after that they started adjusting the distributor and the idle just to try to get it to set right. So I've been playing Hell to try to get it right it seems like every time I ground it out and set the distributor it runs fine for a while and then changes I'm not sure if the ground wire is working correctly. So I'm trying to set the idle back to factory spec so that I can readjust the timing re-Stabley distributor and retirement from there

[pennyman1]

did you check the timing belt install? most people get the belt on 1 tooth off. There are threads on here to time it right.

[Beowulf.50Ram]

He told me he believed it was a tooth off but they adjusted the idle to compensate in colder weather. So I need a starting point on the idle so that I can redo the timing chain an don't have to screw with everything. There has to be a set point for if you have to replace the cable or it's taken apart somthingyso that I can set it then deal with the chain.

[geezer101]

Need to confirm - is it a belt drive (4G64) or timing chain (4G54). Either way, if the timing isn't set correctly it won't matter what you do with the distributor... If it is a 4G64 it will be a simple enough issue to rectify. With all the timing covers off the alignment marks are easy to spot and there are plenty of images to refer to on site to guide you.

[Beowulf.50Ram]

Not sure if this one is a belt or chain I will have to look into that. I had no intentions of dealing with the distributor I wanna adjust the idle then deal with the timing chain/belt then restab distributor.

[geezer101]

This is the chicken VS egg thing. Without having your ignition and valve timing set to run on #1 TDC you will be unable to ensure your base line for idle rpm will be correct. Like trying to compensate a high or low idle speed due to a poorly adjusted carb by over adjusting your distributor, it will adversely affect how the engine runs overall.

[Beowulf.50Ram]

I understand this I plan on redoing the timing an changing the water pump an everything else. I just need to know what the base setting is on the idle screw so that everything is correct when I get finished. My plan is to set it where the factory starts to set it then without running it tearing the front of the motor off an changing the belt/chain an all the needed components then adjusting from there all I need is how to set the idle screw correctly as though I'm starting with a new one PLEASE.

[geezer101]

https://www.ericthecarguy.com/kunena/8-Service-and-Repair-Questions-Answered-Here/46388-mitsubishi-2-4-idle-adjustment

The base idle adjust screw should never be tampered with. It is intended to be a factory set and forget deal (not your fault but this is what happens when someone doesn't follow the rules) I think the only way you're going to get even close is to wind it in all the way and keep doing 1/2 turns until it gets into the ball park. As long as the rest of the tune is out you're taking shots in the dark. Sorry I can't offer much advice as I am not familiar with the FI set up (I'm more a neanderthal tech guy)

[Beowulf.50Ram]

I understand that as I too prefer carbs much simpler to mess with. Yes they messed up a lot of things because he knows nothing about cars. I'm actually fixing another car of his too. Long story short caliper locked up they broke it free with a C-clamp an he drove it like that until it locked up again an it destroyed the abs control/distribution block so I'm fixing it all. A

Thank you for the advice that you've given I'll just go that route as I was going to adjust all the way out an start turning it in quarter turns if I couldn't find answer anyways.

[Beowulf.50Ram]

I need a better note I just found a 91 ram50 with 86xxx Miles for 2000 obo so I'll have another to start my dohc swap on as mine has high miles an way to much rust for me to want to mess with it. It will just be a point A point B vehicle that gets decent gas.