IACV Delete on my 1.6L mx-5 Mazda Miata Engine

#MG #MGmidget #IdleAirControlValve
In this week's episode, we remove the Idle Air Control Valve from the Miata engine. We do this to help clean up the engine bay, but also to solve some issues with our vacuum leak. Boys (and maybe girls?) lemme tell you, she PURRRRS now! Can't wait to show you what else we have in store! And remember, don't forget to be YOU!
Follow me on Instagram @Modern_MG
Follow my brother's build @LittleGreenMG

[@ModernGarage]

What are your thoughts on the IACV delete? 🤔 I’m a fan, what do you think?

[@jasonbenton4937]

I think I need those plates. I gotta do mine this way

[@jasonbenton4937]

I think I need those plates. I gotta do mine this way

[@ModernGarage]

@@jasonbenton4937 So far I haven’t had issues, but also don’t drive it in the cold

[@johnwilganowski5882]

@@ModernGarage Suggestions on where to get the plate at?

[@Maleficent___]

@@johnwilganowski5882 go to your local metal supply shop, they sell aluminum in all sorts of sizes. Get a grinder and a file and make your own

[@johnnycee5179]

That was a great idea swapping the engine

[@johnmacdonald3315]

A delicate balance between simplicity and tough cold idle.

[@ModernGarage]

100%

[@mundanestuff]

that's got to be a big boost in morale, it's running, connected, sounds great, the exhaust manifold looks nice, intake sorted, what more can you ask for? It's still fairly crappy outside, you have a little more time before first spring and before you know it, you'll be running the roads!

[@ModernGarage]

WOOOOOOO! lol

[@johnnycee5179]

In an MG body, beautiful. I love the MGB's but the engines the brits put in them left much to be desired from what I have heard, the Miata 1.6 is an improvement for sure.

[@GregsGolf]

great idea!

[@ModernGarage]

Glad you think so!

[@Blumpton_blueprint]

I think it would have been better to buy a replacement intake tube so you can keep the ISCV and IACV functioning, because it has a resonance chamber in it that’s supposed to boost torque in the midrange. But tbf you did a good job of deleting them so it’s fine 👍🏼

[@ModernGarage]

honestly, the biggest reason i did it was my vacuum leak, and i knew the guy that sold the part. It was a very inexpensive fix to my problem 😛 this car is very much a budget build. Also, I’m not a miata guy so i don’t really know all the normal mods or fixes people do with these engines

[@johnnycee5179]

Just a quick warning. Never use Carb cleaner on a throttle body. It will ruin throttle body. Take it from a guy that learned the hard way. Some guys like that valve cover filter ya put on it and I have tried it, it did look better but honestly the ventilation suffers from it as that filter will get clogged up without even realizing it. I switched mine back but to each his own, just keep an eye on it for clogging.

[@ModernGarage]

good to know… thanks!

[@johnnycee5179]

I cleaned my IAC with throttle body cleaner and haven't had a problem dince. You have done alot of work, painting the valve cover, colored hoses, plug wires but that all personel choice. I have a 91 with the 1.6. It runs great but needs work with oil leaks, p.s. leak, needs either a rebuilt or engine upgrade but that takes mega money. Your doing a fine job

[@ModernGarage]

when i got the engine it was rough, I rebuilt it myself before it went in the car. Was a fun learning process. I appreciate the info and the compliment!

[@johnnycee5179]

@@ModernGarage rebuilt yourself?! Wow, that's an accomplishment. I hope you upgraded pistons and rods, that would help a lot. I have read for more hp an upgrade to the 1.8 would be cheapest way to go.

[@ModernGarage]

@@johnnycee5179 Yea, there’s a guy on KZbin who has a really good video tearing down and rebuilding the engine. Went with the cheapest one I could find in the case that I blow the engine due to my lack of skill but so far so good 🤞🏻

[@roguecitizen9146]

Really cool! I'm currently running megasquirt on a 99 motor swapped into a 91 miata, having deleted the IACV on the throttle body, and was thinking of going back to the stock ecu. Glad you shared this. Also, were you running that with or without the o2 sensor? Curious if having that plugged in could help it warm up more smoothly.

[@ModernGarage]

Glad you enjoyed! The O2 sensor was installed here, but right at the end of that open header so who knows what it was actually measuring 😛 i’ve ran the car since then and it seems to have no trouble starting. That being said, I haven’t driven it since the weather has turned here in southern Ontario so it may still struggle a bit!

[@garageworm17]

You could put a euro 1.6 99 intake on it we have one on are turbo 1.6

[@camerondailey1863]

wow! Im from Texas and we dont often get too cold weather, this seems perfect. Thanks for the in depth video! Also, I need my hands on that plate! Would you mind getting a hold of that neighbor and having him whip one up for me if he wants to make some money? Thanks!

[@ModernGarage]

he has some in stock, message me on instagram @modern_mg and i’ll set you up!

[@tyshea]

@@ModernGarage Do know if he has any of these left? I'm interested in one of them as well!

[@ModernGarage]

He definitely does, hit me up on Instagram and i’ll send you the details @modern_mg

[@snygi4697]

does that effect the how rich it gona run on idle? i have a problem where the idle control valve is always open and in ispection its running too rich does that help if i remove it? sorry for my ban english im from finland😅

[@tonybarata4533]

What your friends name or website I'd like to buy that block off plate from him to do my own. Thanks for your help.

[@roselh1]

Can you install a manual choke with cable from the interior to help with cold start?

[@ModernGarage]

idk if there’d be a way to choke a fuel injected engine, but honestly it shouldn’t be a problem. I’ve started it since and it fired pretty easily 😊

[@steelwitness]

hey man i like the video but i was wondering if this was done on a stock ecu? i assume it was because you didnt talk about tuning a MS or anything

[@ModernGarage]

thanks! yea, stock ecu, so far no major issues, but I've only done a small test drive of the car. I've run it a ton though

[@steelwitness]

@@ModernGarage awesome! thank you so much!

[@jasonbenton4937]

I would also like to know

[@ModernGarage]

see the answer above, all stock ecu

[@ianrasch]

Does the local guy have a page I can buy his block off plate for the intake manifold?

[@ModernGarage]

just his instagram, @thehakunamiata tell him I sent you, he’ll hook you up

[@johnnycee5179]

Blocking the plate I have seen before. There are a few things on the engine that could be done better.

[@ModernGarage]

Like what? Would love some input!

[@alidandech3271]

How air enter the engine while the butterfly valve is closed at idling?!!!

[@ModernGarage]

There is a small port that your idle control screw feeds into that always allows air in

[@bristonhatfield9450]

I just did the delete on my 1990 Miata and I can’t get it started any ideas

[@ModernGarage]

Tough to say without seeing it. The IACV helps it start in cold temperatures, if it is cold it may have a hard time starting. Besides that, a potential vacuum leak if you didn’t seal all the vacuum lines could be a suspect. How was it running before and why did you do the delete?

[@bristonhatfield9450]

Got it running had a vacuum leak on my plate it was slightly bent allowing air in

[@BeforeZack]

You shouldn’t have a breather filter if you still have a MAF, that’s unmetered air, that little filter sucks in, not out.

[@ModernGarage]

you think i should cap it?

[@BeforeZack]

@@ModernGarage well no, the pcv sucks as much as it can but the intake is still gonna want more air, so where that breather filter is you have to run a line to intake, after the MAF and before the throttle body. If you go with aftermarket ecu and run on speed density you can put the breather filter back.