engine sputtering bad need help

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07-23-2009, 06:02 PM
Jiggerachi

engine sputtering bad need help

A few days ago I noticed a shutter on takeoff. I thought it was the clutch starting to slip. Today on the way home at a light it sputtered an backfired but didn't die, felt like it was running out of gas. The CEL came on for a second but went off. Shut it off thinking the timing belt or plugs. Cranked it up and started fine. Engine pulled strong as ever, but if the RPM dipped lower than 2k it would sputter and run like shit. I was able to limp it home but had to rev it like crazy at stoplights to keep it running. Now its a gamble when I crank it it runs fine or sputters.

I'm thinking a sensor or vaccum hose, but need advice on where to start. The sparkplugs are overdue, would they do this?

Sorry for the jumbled post, I'm posting from my phone...that's why I haven't searched yet.

Thanks in advance.
07-23-2009, 06:06 PM
Jiggerachi

Oh BTW yesterday I blew a heater hose. After replacing it I hosed a bunch of old old grease angd gunk off the front of the engine trying to see if I had a front main leak. But it was doing that 'shudder' before I did this and I believe that shudder has grown into this.

Again NO CEL at this time...only blinked once.
07-23-2009, 08:21 PM
Rogue

NGK Blues
http://www.buymazdaparts.com/parts.c...=MIA97&catid=4
NGK Plugs
http://www.buymazdaparts.com/parts.c...=MIA97&catid=4
Do the Fuel filter,
http://www.buymazdaparts.com/parts.c...=MIA97&catid=4
and add a bottle of Techron Concentrate.
07-24-2009, 07:52 AM
MadMerv

Ditto on plug wires.
07-24-2009, 09:54 PM
Jiggerachi

I think I found my problem. I pulled the plugs to let the plug sockets to dry out if there was water in them. When I put them back in I noticed this...Are these chew marks?? Do I have a squirrel chewing on my engine?

http://img.photobucket.com/albums/v4...i/P1060391.jpg
http://img.photobucket.com/albums/v4...i/P1060392.jpg
http://img.photobucket.com/albums/v4...i/P1060393.jpg
http://img.photobucket.com/albums/v4...i/P1060395.jpg
http://img.photobucket.com/albums/v4...i/P1060396.jpg

Im picking up new plugs/wires tomorrow. That should clear this up. It's surprising they can go this bad so quickly.
07-24-2009, 10:11 PM
channelmaniac

Pick up a rat trap or 2 and place 'em under the engine bay on the ground. See if you catch the little bastards that are chewing your wiring.

You may want to check other wires like on the back of the alternator for chewing too.
07-25-2009, 06:11 AM
71dsp

I have a set of plug wires from my wife's 99 that I'd sell cheap. They're Magnecor wires. I bought another set when I was trying to figure out why her car wouldn't start. So now I have a second set that's perfectly good, so I'd be interested in selling them.
07-25-2009, 01:42 PM
Jiggerachi

Ok so I changed the plugs and wires...no dice. still sputtering...

Next is the fuel filter, but man I really really don't want to replace the fuel filter. Probably the worst job ive done yet on the car, i'd hate to go thorugh all that and it not be the problem. Is there anything that I coud check first before doing the filter?? I noticed there was a few small chew marks on a hose or two...are there some particular vaccum hoses that could be bad? Im sure they haven't been replaced in the 160,000 miles the car's been on the road.

Im going to pick up one anyway, but i'd love it to be something easy.

What's the life on an O'Reiley's filter? I think I have about 35k on this one, do they go out this quick?
07-25-2009, 01:56 PM
71dsp

I'd think your filter is fine. Too bad you can't bring the car here. I have a spare cam angle sensor and coil pack that you could try. You think it would make it all the way down to my place?

My guess would be one of those two. They seem to be common failure points for some reason. My wife's started to sputter some when I replaced the coil pack and cam angle sensor last time.
07-25-2009, 02:06 PM
Jiggerachi

well...now that you mentioned it after I blew the heater hose I cleaned the CAS a little and I just noticed a fretch batch of oil leaking out. I thought the CAS O-ring had sprung a leak, maybe the two are realated??

I did notice that the problem only showed up when it warmed up. it ran perfectly fine for 15 minutes then started clunking.

I could probably make it back down there...but it would be tough. It only seems to die at stoplights...I think I could keep it runing, but i'd risk breaking down on 360. Do you have the time today?
07-25-2009, 02:31 PM
Jiggerachi

http://forum.miata.net/vb/showthread...+sensor&page=2

Reading this thread, sounds like it could be the coil packs or the fuel pump. Also rules out the fuel filter since the problem goes away at higher RPMs. Since my car was/is low on gas im going to limp it to the station and fill it up see if the problem changes..this guy says his problem got better the more gas was in the tank,and his fuel pump was going out as well. That might help narrow it down.
07-25-2009, 03:00 PM
Jiggerachi

Filled the tank...exactly the same. The problem seems to be slowly getting worse. Before I turned it off is sounded like it was running on two cylinders, untill I could get the revs up, then it would pull nice and strong. Now it's throwing a CEL when it dies...but gows away when I crank it.

A few quotes from that thread...

Quote:

A coil-misfire will throw a CEL pretty quickly, are you getting one? Most times it will be flashing when it starts missing.

Quote:

The coilpack swap fixed the major "hiccup" while driving.

The new fuel pump fixed the power loss on cornering.
07-25-2009, 03:09 PM
71dsp

Not today, but I should have some time tomorrow afternoon. The cam angle sensor on the 94 is on the front of the valve cover right? That's where it is on the 99. I know some year models (1.6L?) had the cam angle sensor in a different location.

IIRC, the coil packs are the same for 94-99.
07-25-2009, 03:33 PM
Jiggerachi

http://www.flickr.com/photos/pethier...7594256422537/

The CAS is on the driver side of the back of the valve cover. Are the same for the 99 cars?
07-25-2009, 03:51 PM
71dsp

No, 99 is front right side of the valve cover. Coils are the same, IIRC, though.
07-25-2009, 06:11 PM
POS Racing

Did your Rats eat a vacuum hose also? I'd look for more stuff they ate I'm sure they didn't just eat the plug wires.....
07-25-2009, 07:09 PM
Jiggerachi

Yea ive been looking around, but honestly I don't know what im looking at. Im a novice at car stuff, I can do basic work but the vaccum system is beyond me. Any particular hoses to look for? I checked the ground wire on the front of the engine, it felt tight.

I noticed this on one of the plug sockets that came off the car. Does it look like a condensation buildup? Looks kinda like what I found on the magnacore website. http://www.magnecor.com/magnecor1/main.htm

I pulled them yesterday to let any water dry up, but it started raining while I was at the library (hood was closed though) so if there was condensation it might not have dried out. Would the new plugs / wires have solved this though??

Here's the pic...
http://img.photobucket.com/albums/v4...i/P1060402.jpg
07-28-2009, 08:19 AM
Jiggerachi

So last night at the advice of William and Gary I checked for engine codes: none, jacked up the car and banged on the cat with a rubber mallet: no marbles, very solid sounding. Then I cranked it and bumped up the idle. Funny thing, the car ran solid no spuddering for about 30 minutes. I decided to take it out on the road. Felt good so I drove it a good 40 miles up to Stevans place at Propwash. He checked all the vaccum hoses and everything else, we hung out for a bit, then drove back home in the rain. No sputtering at all. Drove fine to work this morning, pulls as strong as she ever did.

3 things I noticed. First, it might be the advanced idle, but the car feels like something's not right, the idle is funny. When you let off the gas it idles at 1.5k for about 5 seconds, then drops back to ~800. Also seems to be up and down like this by itself periodically.

Second, the lifters were clattering something awefull. Ive never heard them clatter that bad. It is time for an oil change, that must be it. That was going to be last week before all this crap happened. I'm not saying it's related at all related at all, just very strange.

Third, there is a noise we noticed under the hood while running, an intermittant, holow plasticy bump noise. Sounds like gurgling coffee pot, or something bumping the hollow intake. Steven listened to the engine and concluded it was not in the engine, but in the intake or something like that. Again, maybe not related, but just very strange.

This weekend im going to attempt to change the oil, air filter, gas filter, run a bottle of Techron, and do a seafoam job. We'll see if it comes back when the gas tank get's low. For now im still...:confused::confused::confused:

I really appreciate this forum and everyone's help. Yall are a real lifesaver. I'd be in bad shape if I wasn't on here. Thank you everyone (71DSP, Black Roadster, Gary @ TDR, and Rogue in particular).
07-28-2009, 08:21 AM
sammm

What is the timing set at? When's the last time it was checked?
07-28-2009, 08:25 AM
Jiggerachi

Umm...Titus set it for me a couple years ago. IIRC we set it to 12. Is there a possibility of it slipping out of time...over time by itself?
07-28-2009, 08:32 AM
POS Racing

Cleaned the throttle body lately?

Mine was loaded with ick cleaned it up and now it idles real nice!

YMMV see dealer for details.
07-28-2009, 08:37 AM
Jiggerachi

It's been a long time since I seafoamed it, and it shows. It was pretty nasty in there. That's top of the list saturday, with oil change.

Anything special to cleaning the throttle body? Other than hosing it down with Deep Creep and wiping the butterfly?

Edit: sorry, I meant cleaning the intake. I am planning to wipe down the inside of the throttle body while im doing the deep creep thing.
07-28-2009, 08:43 AM
sammm

Quote:

Originally Posted by Jiggerachi

Umm...Titus set it for me a couple years ago. IIRC we set it to 12. Is there a possibility of it slipping out of time...over time by itself?

Only if the CAS is loose or the belt has some bad teefus. :tooth: I ask because you said it was clattering badly. It could be detonating because the timing is way off. BTDT.
07-28-2009, 08:47 AM
Jiggerachi

Quote:

Originally Posted by sammm

Only if the CAS is loose or the belt has some bad teefus. :tooth: I ask because you said it was clattering badly. It could be detonating because the timing is way off. BTDT.

But could that correct itself?? At 160K the timing belt is definitely due. (2nd belt BTW)

At it's worst it sounded like my friends 351 ford when he accidently had his distributer instaled 180 degrees off.
07-28-2009, 08:51 AM
sammm

Quote:

Originally Posted by Jiggerachi

At 160K the timing belt is definitely due. (2nd belt BTW)

Could the timing belt be on the way out and jumping or missing teeth? That will mess with idle, timing and make the car run like ::turd::
07-28-2009, 08:55 AM
Jiggerachi

Quote:

Originally Posted by sammm

Could the timing belt be on the way out and jumping or missing teeth? That will mess with idle, timing and make the car run like ::turd::

Im worried you might be right. No more long trips, untill I can get it changed. For now though, i'll do the basics and we'll see what happens.
07-28-2009, 08:56 AM
black roadster

Didn't you tell me you recently replaced the CAS O-Ring? Did you mark it's position first so you could set it back to the correct advance?

I'd check the timing.
07-28-2009, 09:19 AM
Jiggerachi

I changed it about 2 years ago, and yes I marked it and set it back. It's leaking again though, and blew the heater hose tuesday. I replaced the hose wednesday night, before this started. I didn't mess with the CAS at all, but the seal needs to be changed.
08-03-2009, 08:26 AM
Jiggerachi

New problem, maybe related

Didn't think it was worth a new thread.

This weekend I changed the oil, and did the ful seafoam intake treatment. Have a bottle of techron will put it in with the new tank of gas tonight or tomorrow. Idle is smoother, but something stranged popped up this morning on the way to work. Every stoplight the engine would rev at idle. Would this point to a sensor or the AFM?? Could this be related to my original problem?

I managed to catch it in the act with the camera...enjoy.

Pay special attention to this 3rd one. This is what makes me think it's the AFM. Watch the engine revving when im parking, then watch the idle, it jumps up to 2k all by itself, then straightens out. This is not in relation to the AC cycling.

Also of Note, my idle has done things like this off and on since i've owned the car, but now it's much worse.
08-03-2009, 08:56 AM
johnwag

My '94 would do that crazy idle dip thing. I cleaned out my EGR for inspection and the idle issue never came back. It's easy and worth a try.
08-04-2009, 10:09 AM
jerrykr

I know you guys checked the vacuum hoses, but this sure sounds like a vacuum intake leak (stumbling at idle, reving, and run smooth at higher RPM).

I had my battery changed on my PT, and after that the idle went crazy. Turned out I found that the guy broke the plastic PCV valve that is in the general area of the battery, causing a vacuum leak and it was really hard to spot the break, as the hose did not fall off.

In the old days of non computer cars, vacuum leak would be low RPM stumble, smooth out at higher RPM.

These days the computer constantly trys to correct things, and symptoms go nuts.

Remove each hose, one at a time, at the intake, plug with your finger/thumb on the intake, not the hose. If everything suddenly smoothes out, you found it. Of course, put each one back as you go, so that you are checking one hose at a time.

I'm probably wrong! :D
08-04-2009, 10:19 AM
sammm

Doesn't the Miata have an idle control valve? I've never had to mess with one.
08-04-2009, 11:07 AM
Darron65

Quote:

Originally Posted by jerrykr

I know you guys checked the vacuum hoses, but this sure sounds like a vacuum intake leak (stumbling at idle, reving, and run smooth at higher RPM).

I had my battery changed on my PT, and after that the idle went crazy. Turned out I found that the guy broke the plastic PCV valve that is in the general area of the battery, causing a vacuum leak and it was really hard to spot the break, as the hose did not fall off.

In the old days of non computer cars, vacuum leak would be low RPM stumble, smooth out at higher RPM.

These days the computer constantly trys to correct things, and symptoms go nuts.

Remove each hose, one at a time, at the intake, plug with your finger/thumb on the intake, not the hose. If everything suddenly smoothes out, you found it. Of course, put each one back as you go, so that you are checking one hose at a time.

I'm probably wrong! :D

That's good advice; sometimes we forget that old time solutions exist too. Your story reminded me of a pesky vacuum leak years ago when VW routed the throttle cable over the fat vacuum hose to the brake booster. It took several years but eventually the cable housing wore a nearly perfect groove in the plastic check valve. I guess I was never on the brakes long enough to notice but I was going nuts trying to figure out the idle fluctuation. To VW's credit, the replacement hose was shaped different to avoid a repeat.
08-04-2009, 11:33 AM
channelmaniac

Yes, check the IAC valve on the intake.

RJ
08-04-2009, 06:25 PM
SirHustlerEsq

yes, clean the pcv out by dousing it in carb-cleaner.
08-09-2009, 11:24 AM
Jiggerachi

Much thanks for the advice guys. I have been on the couch, sick as a dog all week, and impulsively bought another motorcycle yesterday. I hope to tinker with the car tonight after work.

I know where the PCV valve is, but is there any tricks to cleaning the IAC and EGR valves? Or just pull them out and douse them with seafoam?? I searched all this on Miata.net, but couldn't find any pics or anything.

The IAC is on the underside of the throttle body right? Dies it just come right off or is there a bunch of stuff in the way?

The EGR valve is on the header right?

Seafoam is just as good as carb cleaner, they're both high petroleum products right? or should I just get some proper carb cleaner?

I'll open it up and try to figure it out tonight.
08-09-2009, 11:30 AM
sammm

Quote:

Originally Posted by Jiggerachi

Seafoam is just as good as carb cleaner, they're both high petroleum products right? or should I just get some proper carb cleaner?

DO NOT use carb cleaner on the Miata intake (or any other bits). You need throttle body cleaner. Carb cleaner will eat the finish off of it.
08-09-2009, 12:04 PM
Jiggerachi

^noted. Hopefully I can get to Vatozone before they close.
08-16-2009, 09:21 AM
Jiggerachi

Well, looks like I fixed the wierd idle problem... seems it was a dumb mistake all along.

When I had my original stalling/sputtering problem, I bumped up the idle hoping to limp it back to life. I then read the proper procedure for setting the idle on Mnet, jumping the TEN/GND and going into diagnostic mode before adjusting the idle. I noticed that I did not do this. I had cleaned out the PCV and spraid out the TB as well as I could, I was planning on pullign the TB and completely cleaning out the TB and IAC. I thought i'd set the throttle the 'correct' way to around 850rpm before tearing everything apart. Idle has been silky smooth ever since. Glad I tried this before pulling the TB. I guess the computer was bouncing the revs around trying to figure out what happened to the idle.

:punchout: Another lesson learned...

I am still going to replace the PCV valve when I can get around to it, and I have a spare TB on the way (found it on da dumpsta on Mnet) incase anything ever goes wrong down the line. Cars running fine, and never really did anything to fix it, or pinpointed the original problem...for now i'll throw some rat traps where I park and around my bike in the garage, be more careful next time im washing the engine, and call it case closed.

Thanks for all the help and advise guys, im sure some mechanic would have emptied my wallet by now if it wasn't for yall's help.