Shop Mazda Intake Manifolds

Noises tough even with the video. For now IDK but will show it as a link.........



To me that noise is more like an electric motor failing. Why the idle not so sure so let other chime in.


Code - please post the # but it has one and may have nothing to do with the noise,


T

Thank you so much I dont have the code was at Advance this morning. I just find it hard to believe that sensor is causing that whining noise.

I may not be around too much for some of the day but will suggest some things you could try if you can.
To me the noise could be travelling away from where you might think the source is. It's clear enough you could probably hear it with a mechanic's stethoscope or just a listening rod to your ear. Careful doing that around moving parts.


Could rule out any belt driven item by taking belt off and just run for a quick while to see if noise goes away and if so spin the items on that belt by hand for feel.


To me that noise sounded almost exactly like a small electric motor like a washer pump - power door lock size motor type something gone bad or disconnected and would have to be to spin that much but not near the engine at all. The ticking sounded like normal noise to me from injectors.


That's about it until you can peg it down more precisely. I doubt crank sensor makes that noise even if there's a problem with that circuit?


T

heres another video where it starts to make a hallow like grinding

First things first, I would get that cam sensor code resolved.

That noise is tough. Would need to be there to hear what area it is coming from. Smog pump,alternator, cooling fan, anything that moves really could make that noise, including engine components.

Welllllll! That would do it! Dang plastic engine parts Glad it's found and fixed,


T

White smoke generally means burning coolant, usually a blow head gasket. I would do a compression test before anything else.

Did you pull the vacuum hose of the regulator and check for raw fuel?

What happened with the check engine light? Did you solve that problem?

http://autoforums.carjunky.com/Automotive_Repair_C1/Engine_Troubles_F16/mazda_miata_help_gas_in_exhaust_P104035/gforum.cgi?post=103532;t=search_engine#103532


Believe this or not if you get enough fuel in the cylinder(s) that it doesn't burn at all cause the spark plug is gas fouled, it will produce white gas vapor out the exhaust.

Thank you soo much i will try this in the morning sence it is too dark now and very cold. Is ther any other thing u think it might be if not this regulator?

Leaking injector.

Shane: Check the oil now and just crank for now for tests. Oil could easily be too full now and if you drive it with gas in the oil it won't lubricate diddle or cylinder wash hurt anything lubricated by that much gas. Would hate to hear of perhaps a small problem be the disaster that takes the engine out,

T

M sorry u kinda lost me on the diddle and wash was the sposta say wont? I apreciate any help

Diddle = Not much

Wash in this usage = washes off lubricating oil. No lubrication of cylinder walls will cause rapid wear.

Check that regulator. As said just crank this for test if oil is found too full or smells of gas if this engine is to be saved. If you think there's a chance now change it now even for testing and change again if you find the source problem and fix it before driving it,

T

Have codes read & come back & post the numbers.....Most parts stores will do this for free

The engine light doesnt stay on will it still show a code if the lights not on? It only comes on while driving. But i let off on the gas pedal and the engine light turns off. This happens time to time and sometimes multiple times while driving. Iv never owned a miata and jus bought this one a couple days ago. The speedo says 390,xxxmiles but the engine dont look like thats on it or even the car itself

Yes, the code should be stored in memory but you may have to pay a shop to do that one since it's OBD1.

Ok sweet thanks ill get back with the codes if they dont kno what it is.. do you know what the ticking noise in the top end might be? It isnt always there is comes and goes too

You'll have to make it louder. I can't hear it.

That one you can retrieve trouble codes without a scan tool. There is a diagnostic connector under the hood. Jumper TEN and GND together in the terminal and turn the ignition on. The check engine light will flash the code(s) in two digit format.



Ticking noise could be from the valve train. The hydraulic lash adjusters (HLA) are supposed to take up the play in the valve train as things wear. With the mileage the valve train is probably worn out or you could have HLA problems. Change the oil and make sure you use the correct viscosity (10W-30) to see if that helps.

Code 12 means the engine computer detected an open or short in the throttle position sensor circuit.

This means you need to monitor the throttle position sensor voltage to see if you have a defective TPS, a wiring problem, or a computer issue.

To check the throttle position sensor, you need to use a volt/ohm meter.

This video goes over TPS diagnosing. The TPS operation is the same on most vehicles.

I wud like to know if fuel injector number four, cracked and flooding piston four, would also make piston number 2 not work

You have too many threads open on this vehicle for the same problem. We are telling you what to test and your not giving us any feedback. With the other threads, your making it confusing and leaving other hanging in the wind. Please keep it in the same thread.

Link to another open thread:

http://autoforums.carjunky.com/Automotive_Repair_C1/Engine_Troubles_F16/Re%3A_1990_mazda_miata_P104227/gforum.cgi?do=post_unstick;redo=post_view_flat;so=ASC;sb=post_latest_reply;root_id=104035;post=104035;t=search_engine

Sorry m jus getting use to this site and m kida comfused myself.. i dont have access to an ohmeter can u use one in autozone? Sorry fer the comfusion i jus bought this car m jus tryn ta figure out what is goi. O. With it. And need to learn this site better. Thank you for your help if u have an answer to the last question ill only post on this one link. Can u delete one after youve posted it?

Is that what happened? You have a leaking injector on #4? Did you see if the regulator is leaking?

Is #2 cylinder flooded also?

I don't think that a cracked injector in #4 would flood out #2, so it probably wouldn't be a bad idea to replace them both.

In fact, if you have the money, it probably wouldn't be a bad idea to replace all four injectors just in case #1 & 3 let loose later.

If the injectors were leaking fuel into the cylinders, its possible that those two cylinder could be washed out. That means they may have no compression, so you'll have to squirt a little bit of oil in those cylinders to get the compression to come back up while cranking the engine with the plugs removed, all injector connectors unplugged, and coil unplugged.

You don't want gas or spark going on while your trying to restore compression while cranking the engine.

Yes hopefully this is the only problem i had ordered some racing injectors all four

Shane: I suggest staying OE for replacement parts or could confuse the fix - not certain but may open Pandora's box requiring other alterations to accommodate doing that. Yes it's now an old car but not old enough IMO to fool with things aftermarket, performance or other things,

T

Hey guys i have two questions..1 is when i put cold air intake what happens with the mas air flow sensor plug thats pluged into the stock intake box? What do i do with it and with it not pluged in what will it do?.....2nd i need new wheel bearings in front my car is the 1990 base model, does it have ABS? the bearings i found come together with lugnut bolt hub assembly i need to know wether my car has abs or not....thank you!!

You need the MAF sensor, the engine won't right without it....If that kit is for that model, there should be a way to mount it in to your new system. That part can't be eliminated.

For your wheel bearing, just look at the dash. There should be an ABS light that comes on for a few seconds & then goes out when the car is started..... Or you could just look at the hub assembly, see it there is a sensor with a wire going to it, also there should be an tone ring on the axle....

If you have any issues with the bearing start a new thread......

So what was the final outcome with the running problem??? Did you get it fixed??? What did you do???

Thank you. Ther was a cracked fuel injector and the wire harness for the fuel injectors was bad. As for the white smoke i had changed the oil and put the 5 litter oil change jug into the engine when the engine only takes 3.2 litters off oil. Changed oil again runs great. Still havent figured out the check engine. It blinks once then twice im taking that as a 12 but anywhere i go they cant figure out what it is.

I did the thkng and it blinked once then twiceso m guessin thats a 12 and the book at auto zone said it doesnt apply to my car

At that mileage it is very possible it's your motor mounts. To verify this if you put a floor jack under the engine & slightly jack up engine (with a piece of wood or something so as not to damage the pan) to take take the weight off the mounts & your vibration goes away( while the engine is running), then it's the mounts for sure.....

Don't want to beat a dead horse here but is there absolutely no way to reprogram the computer to increase the idle speed? An increase of 100-150 rpm's seems to make all the difference in the world.

Thanks again.

plsmoothy; The idle spec for your car is 550-800rpm, so as Hammer stated, it is within specs. And, as he said, the idle speed is computer controlled. If the engine is running rough and is within idle specs, you have an underlying problem that is causing the roughness. Changing the motor mounts won't fix the roughness. May even make it more noticeable.
Have you had the injectors ohm checked? Have you cleaned the throttle body and IAC? Compression test? Valve clearances? So many things can contribute to this.....No easy answer.

Sounds like the intake is pretty dirty. Cleaning the throttle plate is good but most shops offer services that run cleaning solvent thru the intake & also disable the fuel system & run it thru the rail also to clean the injectors.

The method I told you about you don't loosen any of the mounts, just put a just under the pan w/wood & a couple of pumps to support the motor & run it. On the ones I've done that had bad mounts this would either eliminate the vibration or make a noticable improvement.

Now I'm assuming you've check all the mounts & none are broken. This method is only to check mounts that have hardened & are transmitting the engine vibration..

Hi there,

I have a 1993 and the same problem. To adjust the idle the computer needs to be re-adjusted. Place a wire between TEN en GND inside the diagnoses connector. Adjust the idle with the flathead screw on the right top side of the t throtthle body. Rotating counterclockwise will rise the RMP. Turn the car of and remove the wire. I have tried it and the RPM are now 950 rmp but it is still a little bit rough. Also cleaned the EGR valve, clean the IAC valve, cleaned the injector etc....

Cleaning the throttle body and idle control motor may help.

Loren, The idle is right where it should be. He just thinks if he runs it higher, the vibration will go away.

The idle for that car is entirely controlled by the computer and not adjustable in any way.

If your getting a vibration, the motor mounts will likely cure it.

Sounds to me, that it is actually overfueling. Could be from a vacuum leak causing the computer to see a lean condition and compensating with fuel? When you mentioned intake manifold, you meant plenum?, right? If any coolant lines were breached, could have air in the cooling system which could affect the CTS reading, again causing a rich condition. If you connected the wrong vacuum line to the EGR, could be opening at the wrong time causing a massive vacuum leak.
The odds of the timing jumping during this process are slim, but if it backfired at any time, could happen in a heartbeat. Check cooling system to make sure it's full. Check CTS connection. Check vacuum source to EGR. Make sure you have no air leak between the MAF and the plenum. Make sure the MAF is plugged in. (BTDT).

Check cooling system to make sure it's full. It is. Check CTS connection. Will do. Check vacuum source to EGR. It is good. Make sure you have no air leak between the MAF and the plenum. No leaks. Make sure the MAF is plugged in. Connected and voltage test good. (BTDT).

You're taking the right steps, double checking everything you did. If the car ran fine before & now doesn't it would seem to be in the area you worked. No SES or codes pretty much tell you all the sensors are plugged in & no wires are pinched (I'm assuming you have a SES light on with the key on engine off).

With the no SES now you are looking at mechanical, fuel, air. stuff not computer controlled. If you drove it far enough you would probably get a rich bank, lean bank, cat code, etc. But you don't want to do that.

After you've triple checked your work, I would start looking at the basics. Pull the brk booster line off while it's running, if it idles up & runs better it's getting to much gas. Put a vacuum gauge on it & check your vacuum. If its low & shaky, it's possible your T belt jumped a tooth. After its warm if the vacuum is slightly low & steady @ idle & drops to almost nothing under load you might have a restricted exhaust. You could pop an O2 out when it's bogging & see if that helps...

I still think it's is something you are overlooking when you put it back together but it sure wouldn't be the 1st time something else on a car failed right after a repair was preformed correctly..... BTDT

Pull the brk booster line off while it's running, if it idles up & runs better it's getting to much gas. Put a vacuum gauge on it & check your vacuum. If its low & shaky, it's possible your T belt jumped a tooth. After its warm if the vacuum is slightly low & steady @ idle & drops to almost nothing under load you might have a restricted exhaust. You could pop an O2 out when it's bogging & see if that helps... Engine will no longer run. It started today ran for a few seconds stalled and won't restart. It just cranks. So I can't check these items.

I still think it's is something you are overlooking when you put it back together but it sure wouldn't be the 1st time something else on a car failed right after a repair was preformed correctly..... BTDT I dont' know about this any more. I have checked, checked and rechecked all connections. My work may have caused it but something else has failed subsequent to and outside of the gasket job. About to throw the towel in and tow it to a shop. My substitute transportation is my F350 dually diesel crewcab and she's thirsty and a handful.

Charged battery and trudged on. Started back at basics. Fuel + air + spark + rotation = running engine.

Starting with fuel I found I had no pressure at the rails and could not hear pump running. Fuel regulator relay tested good. Loosened gasoline fitting at rails. Turned key on - no fuel. Pulled pump relay and shorted connections - fuel spray. Looks like the relay is bad?

But while shorting the connections (with fitting tightened) the engine would not start. Sort of makes sense as I had pressure before and it would not start.

Will pickup light for testing plugs cables for spark.

Reg

It's tough not being there. It really sounds like you've covered your work. I know the Mazda's are a little hard to test fuel pressure due to no port but a gauge would really help. The system will only power up for 2 sec with KOEO (key on engine off).

Going off what you saying, IF there is no fuel pressure and spark, all the grounds have been verified good (along with all the other basics). I would start looking at the Main relay & wiring. The Main feeds the control side of the fuel pump relay along with other systems.... You might want to get a good wiring diagram. Maybe Tom, Loren or Hammer could post one for ya....

But before you jump into this, here is the most important step........

Take a break....Walk away for a day or two... Sometimes when you get caught up in a problem child like this it is very easy to overlook something simple due to tunnel vision... Don't even think about this POS (it's a POS cuz of the problem right now...once you get it handled then it'll be a nice ride again) come back in a day or two with a clear mind & you nail it right off the bat.....

Thanks I appreciate the kind words.

I got another relay from the junkyard to use for testing purposes. Better than buying from the dealer. $2.75 vs $27.00.

After doing a dry run on the junkyard's I tested mine. Guess what mine is good. After a "Look at the sky, scratch head, ask WTF" moment I checked the fuse box side connectors and found an open in the ground circuit for the relay. Control circuit not pump circuit.

I don't know where the box wire reaches ground but if it joins others and thus there is a common ground then that may explain a lot. Something broke or vibrated loose.

More to come.

Reg

Need to find what makes turns on the fuel pump. One person responded that the PCM must see a spark signal to allow fuel. Where do I test for this signal? The spark plug wires themselves?


Each time I try to start the engine it sounds worst than before. It actually did a mild backfire yesterday.

Reg

The trigger ground is how the computer controls the relay. It's simply not turning it on. This can be for any number of reasons. See if you have lost spark also. Check the power feed to the injectors from the ASD relay and see if first, it powers for 2 seconds with key on and then comes back on when cranking. It's common for these to lose a crank sensor and that will shut everything down.

She got a spark and power to the injectors. Got a puff of smoke from below the MAF area on first start this morning and no smoke on second cranking.

I've run out of time on this one. She's being towed in today. Today's my last day off this week then I work 8 (4 12 hour and 4 8 hour days) with only one off in between.

Thanks for all the help. I really appreciated the assistance. Will post what the garage finds.

Moving on to my F350 with oscillating voltage, the 911's O2 sensor installation, shift bushing replacement and tune up and the wife's Camry with a host of needs. Actually the Camry's being replaced. I'm only one man.

Reg

Problem found.

The good news: the problem was found and equally important it has nothing to do with my work.

The bad news: It was the last place the garage looked and the last place I was starting to look before throwing in the towel.

Where you ask? For those who mentioned timing pat yourselves on the back. The timing was off five teeth.

The belt had not skipped because of oil on it but because the tensioner has failed. I incorrectly believed that a skipped belt would show damage. It won't if there's no tension on it.

This will go down as the most expensive timing belt change for a non exotic car. The final bill? I can't bring myself to post it. Lets just say that for five times that I could buy another 626.

The moral of the story: approach a new problem as just that - new. The valve cover job became a distraction for a completely separate failure. The engine started and ran properly after my work thus that repair was done correctly. Things can break at any time whether thousands of miles or years after the last repair or the next minute and 100 feet out of the driveway. The last is so true. I did some work once on an Explorer I once owned. Afterward I went to start the engine and the starter died. Completely separate but we would all likely blame a repair shop had they done the former work. The shop manager for the garage doing work on the 626 says it happens all the time.

I learned something here about troubleshooting and perseverance. I hope there is something here for others to take away as well.

Thanks to all.

Reg

Thanks for coming back & posting the fix......

Yes it's very easy to get "tunnel vision" on a certain area, especially right after a repair.. and a lot of the time, that is the area you need to be.... an old saying " A new problem??? Show me the last area to be worked on and that's where the new problem will be" It's unfortunate you ran out of time and I know you are hatin hindsight at this point.....


But I will say, good job on sticking with it for as long as you did and if you had a little more time you would've got there. I can tell from your posts that you have better than average repair & daig skills (probably better than some of the guys I work with ), so thats a leg up over alot of people. Everyone has had a problem child like this & if they are tellin ya the haven't, then either they're lying or just working on gravy stuff & walking the hard diags....Some days you get the bear & other days the bear gets you....


It sux but at least you were able to take some important things away from this, so I won't call it a loss but a wash.

Good luck with the rest of your projects & don't be a stranger.........

Went to start engine today and battery is discharged. Looks like I also have a ground which might be (part of) the problem.

The entire intake manifold had to be removed to access the rear valve cover. Several hoses and sensors unplugged. I am sure I have reconnected all properly but . . .

What tells me I did is that the engine started and ran normally for a good distance.

No sound of air leakage. The only breach I have found is a large crack in the intake tube upstream of the MAF.

Will look at areas you mentioned. No backfiring occurred. Also plan to unplug and replug sensors in case of bad connection however again scanner saw nothing.

Thanks for reply.

Reg

All of the above "Guests" are me. Thought I was logged in.

I think we are still missing a valid point. Why did the engine start and run well for miles to begin with? Well after it had warmed. What sensor comes into play after the engine is hot?

Reg

The only breach I have found is a large crack in the intake tube upstream of the MAF.

If by "upstream" you mean between the sensor and the throttle body, then that could definitely be your problem. You can't have any unmetered air coming in, in that area or you will have a lean mixture.

The only breach I have found is a large crack in the intake tube upstream of the MAF.

If by "upstream" you mean between the sensor and the throttle body, then that could definitely be your problem. You can't have any unmetered air coming in, in that area or you will have a lean mixture.


No between the MAF and atmosphere. There are no other sensors upstream of the crack.

Reg

Also one thing you can check is the ground straps. I believe there are 2 or 3 grounds on the back side of the plenum, back by the firewall. Look back there & make sure they all got bolted back on to the plenum.