Mykl

My car's ability to act up at the worst possible time makes me want to take it out and firebomb it. I'm leaving for Saudi Arabia in less than two weeks, and all I wanted was to go home and visit my family before I left, but now I can't because of my "reliable" n/a. Yeah, I'm upset.

Here's the story...

Cars running decent, a little sluggish because it's ready for a tune-up. I change the spark plugs and fuel filter. Take her out for a couple runs and she pulls to redline beautifully, no hesitation, no burps, nothing, pulls strong, smooth, and hard to the rev limiter.

After a couple runs it goes straight down hill. No more hitting redline and it sputters really bad all the way to about 7500 RPM's when it stops accelerating.

Drive it around for a while, can't figure it out. I wiggle the trailing plug wire where it connects to the plug and make sure it has a good bite. Viola! Oh wow, it runs great again! Then it eventually deteriorates back to how it was before.

So today, I drive it home from work. Not running better, not running worse. I pull the trailing plug on the lead rotor, dead black, rich. The plugs are only a couple hundred miles old, AT MOST. The old plugs looked fine after 10k miles, far from black, perfect actually.

Put the plug back in, attach the wire, WHAMMO, now the car barely holds an idle. Idle speed drops to zero, somtimes it dies, sometimes it doesn't, then surges up to 900, then drops to just about dead, then surges, etc etc.

My ******* MSD plug wires haven't come in yet, even though I ordered them two weeks ago. So I go out and buy cheapos to see if it changes the situation any, it changed nothing.

Now get this, this is really fucked up. When I turn on my headlights the idle smooths out at 500 RPM's, still idles poorly, but at about 500 RPMs and doesn't attempt to stop running.

The car is also running so rich it's nauseating. Normally my exhaust feels like a hair dryer, no real smell. Now it smells so strongly of gasoline you expect the **** to spray out.

I've messed with the TPS, played with the TB, checked the resistance on the secondary injectors, checked the timing, checked the compression, and everything checks out just fine.

I have no idea why it's doing this, I would appreciate any advice. If you've gotten this far, thanks for reading.

Mykl

Oh yeah, and right now, as it sits...

Not only does it idle like described above, but it runs like total ***. Burps like crazy, power feels "mushy", doesn't hit redline (stops at about 7200 RPM's), and when in neutral the car can't hit redline, only about 7600 RPM's before it starts popping like crazy if I have the pedal floored.

The engine isn't blown. I've lost compression on one engine and this isn't it.

Oh, and another interesting little tid bit. Before when it was running good it would always make one big POP when I shifted at redline. Now there's no more big POP at redline, but it sputters a bit on the way down.

Erik

hey, as for your last post...the not getting pops when you shift at high rpms...over the summer my n/a had a little "spell" for about a month where it did that. i was mostly driving my gf's civic as a daily driver so the rex was just under a car cover since the civic gets mad gas mileage...anyway...mine would always pop before that and then it just stopped...and would stop revving at around 6000. after i had Ito at JR rotary adjust the ports (i'm guessing 6-ports), put in a new O2 sensor, and clean the injectors it runs perfect again.

did you try checking the codes? that might give you a direction to go in. or how old is the O2 sensor? after i got mine back my assumption was that it was mostly due to the 6-ports sticking or not working. cause it returned back to its normal "meaner" sound under WOT. hope you figure it out man

skibum9199

Yeah, my "reliable" na has a similar personality... Did you check the spark coming from the coils? Was it you who said your trailings only fired sometimes? I'd definetly look into the o2 sensor... it sounds like your computer is rather confused and may be in a "limp home" mode running super rich so as to not damage the motor. Did you run the error codes for it? Good luck, I hope ya get it sorted out..


~Jesse

skibum9199

whoops, erik already said a lot of that... that'l teach me to skip the replies...


~Jesse

Mykl

Earlier on it was flashing OT sensor codes. I didn't think that would have anything to do with the idle though.

The sixth ports are working fine, I can move the plunger in and out with my hands.

I'm developing a list of things to be checked an replaced, but I won't be able to play with it until I get back from Saudi in January. I think I'm gonna strip the intake down to the block and, clean everything out, and send the injectors away for some professional cleaning. A new set of gaskets will also be in order.

I'm typing this post to the best of my ability right now, I'm a tad under the influence. I was so pissed I felt the need to consume.


Like I stated above the only code I rrecieved was the O2 sensor code. I just have to wonder if that is as a result of running super rich though.

One thing I dislike about this car is there are so many nit picky ystems that mess with

UniqueTII

The rich condition is a result of the O2 sensor going bad, not the cause. Like skibum said, if the O2 sensor stops sending a signal, the computer throws itself into "limp home" mode and runs mad rich, so as not to damage the engine. An aftermarket sensor is pretty cheap, so I'd suggest replacing it first. When my TPS was shot, I also had a lot of these symptoms, and the voltage checked out fine. The thing would crap out every time the RPMs went up.

j9fd3s

iTrader: (3)

the o2 sensor code, if its the feedback one is a symptom of the car having a bad mixture, not the sensor. for example a vacuum leak

mike

HAILERS

Did you try putting the old plugs right back in and having a go? You should have bought a 86-88. You can cut the o2 wire on one of those and you'll never know it. And on those model the o2 sensor is not in the loop at idle. Boy, they sure musta honked up the system after 88. On a 86-88 you can yank the trail plug wires off and throw them in a ditch and you'll never miss them unless you are into passing emissions. Strange what they musta done to the 89 and up cars. If you have not put the old plugs back in , I'd give it a try. Sometimes we inadvertently damage a plug putting it in or its busted prior to buying it. Thats my three cents. You've already checked and made sure the pressure sensor electrical plug and vac line are on good and checked for the loose vac lines, plug off the air temp sensor and made sure the air flow meter plug are secure. The part where you had the engine off and played with the trail wire and then started the engine and all was well for a moment might make one think the fuel pump or filter is'nt supplying enough fuel. I've heard that models later than 88 have a electrical oil metering pump that if it fails will put the car into a limp mode. Tps checkes out good when you ohm it out from idle to wide open throttle? Yeah, I think you said that, maybe. You must have put the plug wires back on right because you drove it and it drove good for a while. Got me. Sorry 'bout that.

Mykl

I didn't think the O2 sensor made much of a difference at idle, but I'll change that and see what happens.

Now the car just runs like ****. Doesn't rev smoothly at all, the entire car shakes and vibrates when I hit the gas.

Maybe one of my coils has gone out or something. Ugh.

Sometimes I wish I had a Civic.

Node

iTrader: (1)

that sucks alot man
Hope you can get that bitch figured out, and hopefully still have time to visit your fam before you ship out. Hopefully not too many worries on your mind while you're out of the country
Good luck

Mykl

Update...

Oddly enough, after it warms up it seem to be idling better now, even though I've done absolutely nothing to it. It's still very rich though.

Only thing is that acceleration still feels mushy, it sputters a bit all the way to where it stops accelerating at about 7600 RPM's.

What effect does the O2 sensor have at idle?

This is really confusing me, what on the car could fail and cause and incredibly rich condition?

Erik

hey, what exhaust did you have again? do you still have the stock manifold box? did you have the N1 or was that defylogik

pd_day

iTrader: (6)

Hey Mykl, did you finally find out the problem?
My car is doing the exact same thing, just at a lesser degree.

mazdaspeed7

Have you checked your TPS? It might need adjustment. Use the voltage method, its much more accurate. Bend 2 paperclips so they both have a straight piece an inch long, push them into the back of the the plug for the TPS on the top and bottom wires that go to the narrow range TPS(front one), and check the voltage at idle. It should be 1V.

pd_day

iTrader: (6)

Is this method for a series 4 or series 5?
Does the car have to be on?

Are testing on the plug from the TPS or the plug from the car?

say the pins are numbered below with the clip up:
clip
1 2 3
4 5 6

which pins do I test for??

Thanks

jarrod

i would try another set of plugs,i bought a set last
year for my zx ninja it ran like a honda,bought another set
ran perfect...

mazdaspeed7

It is for both S4 and S5 engines.

Just look at the wire colors for the short range TPS, and follow that back to the plug. Its either 1 and 4 or 3 and 6, but I dont remember which pair.

Keith

3 and 6, or 3 to ground. Check out the Water Thermosensor under the Alternator also.

Irv, Keith's dad