92turbomiata

Ok the tapping noise seems to go away now after it has warmed up. I guess it's just hla clatter.

Still battling another issue with what feels like a hesitation once I get into boost between about 4500-5500 rpms. It just feels like it's bogging down a little but if I keep in it it will clear up eventually and start pulling really hard like it's suppose to. I'm kind of at a loss at this point.

I guess I should mention that I did a compression test.
Cylinder 1 - 255
Cylinder 2 - 255
Cylinder 3 - 215
Cylinder 4 - 255

Now number 3 is the same cylinder I had to repair the spark plug threads on. When I was doing the compression I could see and feel the air escaping around the spark plug hole which would account for the lower reading on that cylinder. I put a tablespoon of oil in it and did it again but the reading only went up 10 points and I also got the tester as tight as I could so I don't think it's a ring issue. Could this be causing the slight hesitation I am getting? I am already looking around for another head to throw on there.

92turbomiata

Here is a screen shot of 2-3 pull. Note that the afr reading in the datalog is about .4 leaner than what the wideband shows and I have compensated for that so it's running .4 richer than what it shows in the graph.

curly

iTrader: (25)

You could always JB weld it. Just a little on the threads of a spark plug and it should seal the gaps. It'll break loose once you try to loosen it.

92turbomiata

I think it's more of an issue with it not sealing between the head and the heli coil. I would take it out and jb weld it but I'm pretty sure its stuck in there. I will try jb welding the threads on the spark plug just for ***** and giggles though.

hornetball

iTrader: (4)

And, yes, low compression will cause a miss/hesitation -- especially at low RPM.

Those are really high numbers BTW. Do you have high compression pistons or are the units something other than psi?

92turbomiata

It drives fine at lower rpm. No hesitation. Only really does it under boost.

Yes high compression pistons. Supertech 11:1

92turbomiata

Ok it seems to have that hesitation/misfire around 4000rpm even when not in boost. At this point I have checked almost everything I can think of and I'm leaning towards the leaky heli-coil insert on number 3. Maybe I'm missing something stupid, any suggestions on what to check now?

I drove it last night for a little bit and when I was done the number 3 spark plug wire had popped out about 1 1/2 inches so I know it's leaking pressure.

sixshooter

iTrader: (12)

Head swap. You don't have a lot of options here.

92turbomiata

Already working on it. Found a head locally that I picked up yesterday. Got the head off the car last night and I don't see anything else that could be bad. Bottom end looks good from what I can tell. I'm about to start on swapping intake over and injectors, etc. Should have it all back together here in a few hours and I sure hope this fixes it. I will post a few pics of the internals in a minute so you guys can see if something doesn't look right.

92turbomiata

Ok got it running with the new head and it's still doing the same thing. I'm thinking either an injector issue or coil issue. I guess it could still be a bottom end issue and I just don't want to accept it but I find it hard to believe that if it was a bottom end issue (ring, etc.) that it would drive with a slight hesitation/misfire all the time not just above 4000rpm like it does now.

I need help guys. This is driving me nuts

Monk

iTrader: (3)

Did you do another compression test? You might be able to at least rule out a melted ring.

92turbomiata

Did another compression check with the new head on there and now all 4 cylinders are showing 255. So it's not a ring issue. It's gotta be in the tune. Spark plugs are white which would mean it's running lean although it's at 12:1 in boost. This is e85 on a "pump gas" calibrated mtx-l wideband. Will try adding more fuel tomorrow to see if it gets better.

92turbomiata

Ok.....after much dicking around and trying to fix the issue of falling on it's face around 4k rpm the problem is finally fixed. I tried just about everything I could think of to fix it along with several tests of the ignition and fuel system and they all checked out ok. Went to see my buddy Ian last night who has been helping me tune the car. Long story short, it ended up being to RETARDED of ignition timing!

I didn't want to really touch the timing until I got it running like it was suppose to since I was afraid of knock and all that with the high compression and boost and didn't want to blow up the new engine. However we started adding a couple degrees of timing here and there and it slowly started getting better. In the end we ended up adding about 10 degrees of timing from where it started. She pulls so much better now and does not break up at all. I'm a happy man. Now that I have a decent timing map it's time to start increasing boost and having fun. Also hit over a 1000 miles on the new engine yesterday and she's still nice and healthy.

18psi

iTrader: (76)

very cool congrats man, glad you finally figured it out.

can't wait to see what this thing does at full tilt

curly

iTrader: (25)

Just be cautious, adding timing without knock detection or a dyno graph is bad joo-joo.

92turbomiata

I have an electronic det can that I made that's currently on the car. Didn't hear anything yet. I will eventually get it to the dyno so I can get everything dialed in. I'll try and get up a video later of a 1-3 pull. It's fluctuating between 8-10psi right now but it's still pretty darn quick. Maybe I'll try a Virtual Dyno log just to get an idea of where its at.

92turbomiata

Ok guys, it's been a while since I have done an update. Been busy with work and holidays but still been working on the car. As of today the car is still running strong! And my engine hasn't blown up yet so that's good. And I also installed a bigger Turbonetics turbo that I had laying around that I was going to use on my other car but never did.

I have had to pull the engine again due to stripping out 3rd gear in the transmission when merging onto the highway and rolling into the throttle. Right around peak boost it stuttered and made a bad noise, I thought the worse, threw another rod, spun a bearing. Pulled over immediately and the engine was still running fine but it had a very loud metallic clunk and it speed up with engine revs so I thought I had spun a bearing. But after a little more investigating I figured out it was the transmission as the noise would slow down and go away when I held the clutch in. I tried to limp it to a parking lot and it just got worse and the noises got louder eventually locking up the transmission completely. So I had it towed back to the shop were I spent the weekend pulling the engine and trans and cleaning the engine bay that had oil everywhere from a botched front main seal install that was leaking badly. Swapped in another 5spd for the time being since I already had it laying around. I got my eyes open for a 6spd which I know I'll need sooner rather than later.








After that I drove her around some more trying to get the EBC to behave properly but still haven't great success. It hits target boost then immediately drops 5psi then comes back up and then fluctuates about 3-5psi then entire pull. Makes it nearly impossible to get it tuned. So I got fed up with messing with it and decided to make my engine bay look nicer so then this happened.



























All Done





Also added old AeroDramatics needle caps and carbon fiber mirrors. Boy those mirrors are light!






Also got a GoPro from the girlfriend that I have been playing around with. I've got several videos I will upload later tonight so you guys can see the car in action. Its still only on 15psi but boy she's quick.

aidandj

iTrader: (5)

I had the same issue with tuning EBC. How are you going about tuning it? I followed the steps in this thread and there is a lot of good info there.

https://www.miataturbo.net/megasquir...s-80434/page2/

turbofan

iTrader: (1)

Damn, amazing what a wire tuck does. Nice work.

92turbomiata

Thanks! It was a lot of work. About half way through I was second guessing myself lol. But over all it really wasn't to hard, just time consuming. I spent about 3 weeks doing that just working on it after I got home from work. Overall it probably took about 10 days to do the wire tuck but I'm glad I did. It looks so much cleaner and nicer now. Also got rid of the A/C evaporator and replaced it with the OEM plastic tube. Got rid of all the the airbag crash sensors. 3 in the front bumper and one under the dash, also got rid of the airbag computer and backup battery. I removed a total of about 40 pounds between all the little brackets, a/c evap, and airbag stuff. And the main fuse box is easily accessible since its right behind the glove box.

Now I need a new, nice steering wheel as I didn't put the airbag back in so right now its just the factory wheel with a big hole in it with all the bare metal exposed. Been wanting a new wheel anyways.