to be honest i dont know how to describe my problem

[ffemtcurrence]

ok 2 weeks ago a coolant line split open and my engine got hot so i fix the leak and ever since then my car has been missing, sputtering, and completely junk...so earlier tonight i took apart and cleaned the IAB/IAC Valve "the nostrils" and the throttle body...and wow no more codes no more stumbling and lots of power....well after driving around for an hour i come to a stop light and what do you know another coolant leak (not near water pump, bit the hose under the throttle body) and my car is now throwing codes again and stumbling and the strong smell of gas...so my question is how would leaking coolant basically **** the performance of my engine....so tomorrow do i have to take apart the iab again which to be honest was a pain in the butt and clean it...or what this is really driving me insane..i mean a 3 hr job destroyed in an hour....
the codes were

172 (R,M) Oxygen sensor not switching - system is or was lean - Single, Right orr Rear HO2S - Fuel control

181 (M) Fuel system was lean at part throttle Single, Right or Rear HO2S - Fuel control

412 (R) Idle speed system not controlling idle properly (generally idle too low) - ISC


i have new o2 sensors on, and like i said after cleaning the valve every code and problem disappeared...please for the love of god :thankyou::thankyou::thankyou:

 

[bittertech]

I had a sneaky leak in my miata that would cause air bubbles in my coolant. Air bubbles would make the coolant sensor read hot, which the computer would try and compensate for by pulling fuel (colder = more fuel, hotter = less fuel)

Fix the leak, burp the system. And yes, the coolant sensor is right there near the throttle body.

 

[ffemtcurrence]

how do you burp the system

 

[bittertech]

with the car cold, open the radiator cap. Start the car, run the heater with the fan on low. You'll probably want to use your hand to open the throttle some as waiting for a car to warm up at idle and the heat on can take awhile. Have some coolant ready. Right before the thermostat opens and the radiator fan kicks on, the coolant will be bubbling out of the radiator. Once that thermostat opens, the coolant will be sucked down the radiator and into the engine - so be ready to pour coolant in.

Let the fan cycle twice, as soon as its filled the second time toss the radiator cap on. That should have gotten the majority of the air bubbles out of the system.

Also, if you don't know about it - you can borrow a coolant system pressure tester from Autozone for $80 (return it and you get your 80$ back). It's a little hand pump that fits in place of the radiator cap and will make almost any leak in the coolant lines spurt out and be obvious to catch. I would have never caught the slightly cracked line in my miata if it wasn't for the kit. Once pressurized, it was obvious where it was ******* from.

 

[ffemtcurrence]

ok guys seriously i need help before i take this car to a junk yard out of frustration.....i keep getting the codes

181 (M) Fuel system was lean at part throttle Single, Right or Rear HO2S - Fuel control
412 (R) Idle speed system not controlling idle properly (generally idle too low) - ISC
538 (R) System did not receive "goose" test

ive replaced the TPS, IAB, O2 Sensors, New DIS, fuel filer...cleaned the MAF...im still getting a horrible miss and my car just doesnt want to go anywhere.the 1st start of the day is flawless...but when i turn it off after its warm it takes forever to start the 120k was done at 100k...the cylinder balance test says #3 is weak...im getting spark on all the coil pack contacts....i also have a strong smell of gas when the car stumbles and the check engine light comes on...im down to the last 200 bucks that ive had saved up for this car

 

[hawkeye18]

Sounds like when the coolant shot out, it soaked the rear of the engine and fouled out the #3 spark plug/wire contacts. #3 cylinder is the back right cylinder... right by the throttle body and said coolant hose.

When the spark at #3 gets extinguished, the spark at #4 gets extinguished as well, due to the dual-spark nature of the engine. Since your engine is now running on 4 cylinders, it feels like crap and has no power.

However, it seems that this would cause a rich code, vice a lean code. Perhaps a vacuum leak? You should reset the codes (remove the paperclip/code reader while the codes are displaying to reset them)

Start off by replacing the spark plugs, all 6 of them. If that doesn't fix it, replace the wires. You don't have to remove the intake for the plugs (a long extention and a wobble joint are your friends here) but the wires will probably require the intake to be removed.

I've heard it here before, and it still stands true, 80-90% of all stumbling/misfire problems can be traced back to the plugs and wires.

Oh, and the 538 is caused by not nailing the throttle during the KOER test after the single blink of the CE light. Of course, if the engine doesn't have enough power for the RPMs to go up enough, then you're screwed really, but that test is only to test the knock sensor. Ignore it if there are other faults.

And the 412 is there because it only has 4 cylinders to idle on!

 

[ffemtcurrence]

thanks hawkeye i forgot to mention i already put in new plugs and wires and the plugs are correctly gaped.....i cant hold the throttle and cruise it will buck...another weird thing is is if i stay in 1st gear and keep the rpms at 5-6k and then floor it and slam it into 2nd the car feels like its really alive it has most of its power until i let up then the CE light comes back on and the car bucks again...could it be a fuel problem but then why would it buck at part throttle and not full throttle and high rpms...like i said when the CE light turns on a very strong oder of gas comes from the engine and you can smell the unburnt fuel through the exhaust...which would make u think it would be running rich but theres a lean code so im stummped as you are....if you have anymore advice thanks....maybe one day i can return the favor of helping you with something lol even though i dont know much