YACT: WTF did I do...

[iamwiz82]

1999 Miata

I supercharged my Miata and yesterday was my first attempt at turnover and it was a failure. It fired and bogged immediately at about 500 RPM and then shot to 900RPM, then stalled out. Second attempt started and surged to 3000RPM immediately and then slowly came back down and stalled out. Now every start is either one or the other. There is a strong odor of gasoline, so I am wondering if it's running so rich as to stall out.

My thoughts:

1. I re-wired the TPS and IAC and am wondering if I screwed up a wire somewhere. I would check the continuity of each one, but of course my multimeter decided to die today.

2. The new ECU parameters are flooding the engine out. I cannot seem to find a baseline setup for a Miata with a Greddy Emanage Ultimate.

3. Vacuum leak. I checked and rechecked every hose and clamp and they all seemed fine.

I hate electronics on cars.

EDIT: See below

 

[KLin]

I have absolutely no experience with supercharged motors, but I would check the air intake.

 

[Sukhoi]

It's the vapor in the blinker manifold.

 

[KLin]

Originally posted by: Sukhoi
It's the vapor in the blinker manifold.

Are you sure it's not the exhaust in the headlight solenoid?

 

[nakedfrog]

Yeah, sounds like it's one of those three to me.
Maybe it's dumping in as much fuel at idle as it would at WOT?

 

[SlowSpyder]

Probably not your problem, but now that you're boosted you may want to look into creating something like this:

http://www.mirage-performance.com/EclipseGSX/BoostLeaks/index.html

That is what we use in the DSM world to look for vaccum/boost leaks. Connect that to your intake and put a few psi through it with your compressor, you'll hear any leaks. Much better then just visually inspecting the car for leaks.

 

[iamwiz82]

Originally posted by: SlowSpyder
Probably not your problem, but now that you're boosted you may want to look into creating something like this:

http://www.mirage-performance.com/EclipseGSX/BoostLeaks/index.html

That is what we use in the DSM world to look for vaccum/boost leaks. Connect that to your intake and put a few psi through it with your compressor, you'll hear any leaks. Much better then just visually inspecting the car for leaks.

That's a very cool idea. I'll have to build one.

I checked the continuity of my wiring and everything looks good. The damned thing sound great at 2000RPM, but it's very difficult to keep it there.

Tomorrow I am going to pull the new ECU to see if the old one will get it to idle.

 

[thedarkwolf]

You would be much better off on one of the miata forums. I have a turbo charged 94 myself, fun stuff .

 

[Exterous]

I would check your Flux Capacitor

 

[Rogodin2]

The damned thing sound great at 2000RPM, but it's very difficult to keep it there.

ROLF!!!

Either you're lying or you're being dense!

Rogo

 

[JulesMaximus]

Should have bought a Lotus Elise.

 

[iamwiz82]

Originally posted by: thedarkwolf
You would be much better off on one of the miata forums. I have a turbo charged 94 myself, fun stuff .

Not getting many answers over there.

Should have bought a Lotus Elise

Bah, what fun is it to have a toy and not modify it?

 

[biggestmuff]

Uh...wrong website forum.

I know there are plenty of Miata websites that will be able to assist you.

 

[Aikouka]

Pictures!

 

[Roguestar]

Originally posted by: Exterous
I would check your Flux Capacitor

god damn you I came here to post that

 

[Mr Pickles]

This thread is going no where.. thought I would help it get there faster with a :roll:

 

[iamwiz82]

No thanks to you guys I got it running! Woohoo. It runs like utter crap at idle, but once I rev it everything sounds fine. To be honest, it sounds like a lumpy cam in a 70s era muscle car.

Things I noticed:

The spark plugs were completely covered in soot, and these were new ones. Apparently I am running ultra rich and I am not certain why. Any ideas?

Lots of water mixed with carbon is coming out of the exhaust. Coul be from the dozens of poor starts.

 

[Toastedlightly]

I've been in the same boat recently.. put 750cc injectors w/ a big turbo on an SRT4. Also, those signs point to rich. Do you have a wideband O2 sensor and fuel pressure regulator? Those two are extremely helpful in the tuning process.

 

[Zorba]

Originally posted by: iamwiz82
No thanks to you guys I got it running! Woohoo. It runs like utter crap at idle, but once I rev it everything sounds fine. To be honest, it sounds like a lumpy cam in a 70s era muscle car.

Things I noticed:

The spark plugs were completely covered in soot, and these were new ones. Apparently I am running ultra rich and I am not certain why. Any ideas?

Lots of water mixed with carbon is coming out of the exhaust. Coul be from the dozens of poor starts.

The water/carbon in the exhaust definitely make it sound like you are running very rich.

Probably not the problem, but you might check the O2 sensors.

Were all the plugs covered in soot?

 

[pray4mojo]

this sounds like something id definately ask on the miata forums...haha

has your car been tuned yet?

 

[Wags1974]

Ok tps wiring is usually a 5volt reference signal and the tps acts as a rheostat sending the ecu a variable resistance kind of letting it know that hey im XX% open so you need to adjust shift points , fuel injector pulsewidth etc..If anything is wrong with this signal your car is going to run and shift like a turd. (yep even shift most cars use the tps to decide how agressively to shift, you may well be manual so this may not apply to you)

You say you have continuity, to me that shows you really dont know what your looking for. I can scramble every wire in the engine together splice them up and Ill have some wonderful continuity yet nothing will work. What you want to see is a reference voltage to the tps, a variable voltage back depending on how far the throttle is open. Sometimes there is three or four wires so you will have to look up exactly what to look for in your particular car. I will say if you have a reference in and a variable back I would personally be satisfied with that.

Oxygen sensor does not sound at all like the problem but I am betting they will qu ickly become one. Oxygen sensors rely on a galvanic reaction and that reaction just wont take place when they are caked with raw fuel and water. Running rich most likely isnt "because" of the 02 sensor but it will quickly kill it / them.

EDIT:

You also said you rewired the IAC. This can be a problem also because if you wired it incorrectly it could go wide open and then your ecu would respond to a "false" lean by increasing fuel injector pulsewidth.

Once more "continuity" is simply a test to see if EVERY strand of the wire is broken or not, or a test to backwards engineer a wiring diagram on a pcb or other proprietary circuit, please understand that its usefulness beyond that is limited. It can help you make sure that your getting ready to check the right wire from one place to another, thats about all i use it for anymore.

Goodluck!

 

[91TTZ]

Originally posted by: iamwiz82
1999 Miata

I supercharged my Miata and yesterday was my first attempt at turnover and it was a failure. It fired and bogged immediately at about 500 RPM and then shot to 900RPM, then stalled out. Second attempt started and surged to 3000RPM immediately and then slowly came back down and stalled out. Now every start is either one or the other. There is a strong odor of gasoline, so I am wondering if it's running so rich as to stall out.

My thoughts:

1. I re-wired the TPS and IAC and am wondering if I screwed up a wire somewhere. I would check the continuity of each one, but of course my multimeter decided to die today.

2. The new ECU parameters are flooding the engine out. I cannot seem to find a baseline setup for a Miata with a Greddy Emanage Ultimate.

3. Vacuum leak. I checked and rechecked every hose and clamp and they all seemed fine.

I hate electronics on cars.

I don't have any experience with Miatas so I can't tell you the exact cause of your problems. But I will share one experience I had with my 1986 300zx, maybe it can at least give you some ideas.

My old Z one day started stalling out when I tried to drive it. It would idle fine, but would stall if I tried to give it gas, and it wouldn't rev more than 2000 rpm. I unplugged the airflow meter and the car wouldn't idle, but seemed to rev fine. Under 2000 rpm was non-stop stalling, but if I kept it above that it would drive ok. This enabled me to get the car home so I could installed a new AFM.

Most cars nowadays don't have airflow meters so I don't think this is it. But I wouldn't be surprised if it was one of your main sensors used to run the engine like the MAP sensor, throttle position sensor, crank angle sensor, temp sensor, etc. Even with a supercharger your car should idle fine, since it doesn't take much more air to idle than it did before. Something's out of whack.

Did you upgrade to larger injectors without changing the fuel maps on the ECU?

 

[iamwiz82]

When I say I checked continuity I mean that I confirmed that all the wires running in the new loom were going to the correct spots on both sides. I clipped off each wire on both side, tested to confirm that I was indeed looking at the correct one, and then re- crimped/soldered. So when I say I checked continuity, i was making sure my wiring wasn't crossed.

I am running stock injectors still with a revised fuel map managed by eManage Ultimate.

I am going to pull off the SC today to look for an air leak. I'm thinking that the vacuum is all screwed up due to a leak somewhere. I am assuming it is not electrical because I am not throwing any codes at all, not even misfire, which is suprising to me, since it certainly sounds like it is.

 

[lenjack]

Your veeblefetzer phase polarity pulse isn't properly calibrated.

 

[Shawn]

Damn that sucks. When I supercharged my 94 miata everything worked perfect on first start. You have no idea how excited I was considering the most mechanical thing I had ever done before that was change the oil. I would check the TPS connection. If it doesn't have a good connection it can cause the problems you described.

edit: This is a JR Supercharger correct? What do you have the vacuum hose on the right side of the inlet port connected to?