BOTTLEFED

iTrader: (1)

OK, I've searched and searched and have been fighting this problem for awhile now. I finally blew up my original motor and have put in a Mazda reman. I hoped that the problem would go away when I put in the new engine and added a PFC. But it is still here. Here are my mods just to help solve this.
PFC w/ commander, all vac. lines silicone, DP, gutted cat., intake, SX fpr, all emissions removed, Magnacore wires, Greddy pullies, Haltech A/F meter, and Defi boost gauge.

History: I finally got the car going after I bought it with an engine fire. I got a new wiring harness and replaced a lot of fried stuff under the hood. I also had to replace the ECU. I was so happy to have the car running that I over looked a lot of little problems. It made a loud clattering sound when boost built up. It still seemed to pull strong and boost built up to 10psi. But then the clattering got louder and louder. I suspected detonation but from what I had heard, detonation kills rotarys quick, and I had been living with this for months. So I just kept driving it. Then it finally blew a front apex seal.

So now I have installed a Mazda reman and replaced all the gaskets and important stuff. I start 'er up and have the same problem. The only thing that is the same is the ignition coils. I tested the ohms on each and they were perfectly within specs.
My question is, has anyone had experience with the coils becoming to weak to spark during boost? That seems to be the only thing left.
Please help if you have had this problem or know anything about it. Sorry for the long post.
TIA,
Tim

adam c

iTrader: (2)

Have you checked your turbos for excess play?

If your coils were bad, I would expect that the car would not pull smoothly under boost. I would expect hesitation, especially at higher rpm.

BOTTLEFED

iTrader: (1)

Yes, when I had the engine out I checked the turbos for wear and movement. I forgot to mention that I replaced those with a low mi. set from a forum member.

BOTTLEFED

iTrader: (1)

Just to clear things up a bit, here are the symptoms when I drive it.
Warm starts are fine, but cold starts it sometimes stumbles and dies. I figure the PFC just needs tuning.
Idle is good.
Off idle and between shifts it will hesitate a little - again, just PFC tuning.
Drives pretty smooth and power feels just a hair-trigger away. However, it will bog if you put your foot to the floor quickly. If you just roll on the throttle, it will accelerate nicely until vac. hits zero and boost starts to build. Then comes the clattering (knocking?) and, from what I can tell, the ECU/PFC starts retarding the timing until the car just stumbles and power pretty much drops off. Boost will peak at .6-.7 bar according to the PFC but the car does not like it at all.
I have been thinking of disconnecting the knock sensor and see how it goes since the PFC retards the ignition so much. If its not knock, then it should be fine. If it is, I'll probably blow up the motor.
BTW, this morning I tried reving it out of gear just to see what it would do. I watched the knock and boost level on the PFC. I tried one just rolling on the throttle slowly and went to 7000rpm. I hit a high boost of .065 bar and knock peaked at 125.
Then I did a rev from idle to redline and just stepped on it. Readings were pretty much identical with just a little more knock.

adam c

iTrader: (2)

If its not the turbos, I can't say what it may be without hearing the noise. I doubt it is your coils.

Good luck finding the problem.

Power_Put

check for the main bearings of the ecentric shaft see if there is any play i dont think its that anyway but check

try relpacing the leading coils i once had a problem with the leading coils when rpm starts to climb and ecu starts to pour more fuel when boost starts to built it would start to run like **** do you see black smoke from tailpipe when it does the sound

and power fc does not retard timing and try searching on 3 gen forum.

good luck mate

BOTTLEFED

iTrader: (1)

PROBLEM SOLVED!

Well I'm sure this has not happened to many people, but here is what I found.
I went to Logan today to help Chris (respecttheseven/pre-auto guy) do the silicon vacuum line replacement on his new FD. I figured since we would have his UIM out and everything torn apart, we could do some parts swapping with my car to troubleshoot my problem. I wanted to start with the ignition coils because that was #1 on my list of culprits. So I take off my UIM and pull out the coils. Then I go over to Chris' car and I see it right away... the color-coded plugs on the harness - blue, black, and white - are backward from his! But I try to hold back my excitement just incase that is not the only problem. I install his coils and harness - just the way it came out of his car - into my car. Start it up and notice a big difference... take it out on the road and no noises, knock, clattering, sluggishness, nothing but boost :!:
(well, a little lower than it should be but enough to put a smile on my face )

So why did I not see this before? I had the motor out? and the coils a couple times in my many technical adventures?
Good questions, but my only excuse is that, when I bought the car, that is how they were connected to the coils and I just assumed that was right. It didn't seem that the plugs from the harness could be connected to the coils any other way. Well I was wrong. The harness just needed to be flipped over

I doubt I will ever forget that the white connector goes on the trailing front, the black to the leading coil, and the blue to the trailing rear.
Sorry if this doesn't ever help anyone else, but I thought I would let you know how it was resolved.

jspecracer7

Get a compression test done. I did that same thing about 3 years ago and blew my motor doing it. The reason is when the trailing fires for the front, if it is placed on the rear rotor it will make the rear rotor fire ON TO the apex seal....all 6 of my apex seals were missing a small piece out of the center of all of them

BOTTLEFED

iTrader: (1)

Don't tell me that!
I just put in this reman a couple months ago. But you may be right, the original did finally go out after about 6mo. running this way.

I just cannot believe that it ran at all with the coils firing so far off. I was timimg my truck the other day and was off by just a few degrees and it would not start

Sometimes rotarys just baffle me