Rebuilt 7M, bad rings?

[RacerXJ220]

Well I came back from korea, and started to finish breaking in my newly built 7M from 1 year ago. So I drive around and hit the 400 mile mark from the initial rebuild. I am running pig ass rich, with recently installed MAFT and SAFC together, with the 3.5 inch MAF.

So the engine felt great. I decide to boost to the wastegate's 10PSI to 4K rpm. It felt great, but afterwards I see smoke after I stop at a traffic light. When I accelerate theres a plume of smoke, and then it went away. There's a problem.

I take the oil cap off, and i see the tell tell signs of bad compression as I see smoke coming out of the oil fill hole in the valve cover. The engine has always had a missed idle due to plug fouling, so I decide to pull the plug wires one at a time to see which cylinder(s) is/are bad. So I pull number one out, and there's no change in the engine sound... After that thought to myself "do i really want to rebuild the engine again?" So I walk away.

I believe strongly it's running rich, because i keep fouling the plugs, and they smell like gas.

Could it have been I ran lean? I doubt it. The SAFC was correcting at -5% across the board.

At times it won't stay idle, it will just die.

So I'll be taking it apart eventually, perhaps tomorrow to verify whether or not I want to rebuild it or not.

My wideband is scheduled to arrive tomorrow on the 17th... sucks for me.

The motor has basically sat without anyone starting it for about a year. during that time it was started and left to idle for 30 mins at a time maybe three times.... bad for a rebuilt engine not broken in.

I'm sick and tired of this crap. I used the rings which came with the ROSS pistons .20 over.

What are my options here for the rebuild. If the rings are bad, would regular replacements work or would I need to rehone the cylinders and buy new pistons???

Too much fuel damage the cylinder walls perhaps???

 

[jdub]

Doesn't sound good...but perhaps there's hope:
Black smoke = Rich
Blue smoke = Oil
Smoke from the valve covers = rings

Your smoke from a stop is likely a combination of the above...get the rich condition sorted out 1st. Consider removing the piggybacks and use just the ECU...check for codes that might make your rich condition worse. Get the car running at 14.7 AFR (since you're getting a wideband) for a good base before adding the piggybacks into the loop.

After this is resolved, re-access after running it for 500 miles or so. If you are still getting blow-by on one or more cylinders...well, it's the rings.

The 30 min runs didn't do the motor any good...might have glazed the cylinder walls. Are you using syn oil?
Doubtful that fuel damaged the cylinder walls.

If it is the rings, a hone with a new set is all you will likely need. Unfortunately you have to pull the motor to do it.

Edit: Just re-read this...if the #1 cylinder has no compression (you need to test using a gauge)...it's the rings/piston. Ignore the Piggyback stuff above...you'll have to pull the motor and re-ring. You pistions should be ok, unless you just happened to get a bad one. When it goes back together, I would break in using the ECU only and get it running right before adding the piggybacks.

 

[RacerXJ220]

I was running Lex AFM/550's before the rebuild, then my electronics went out, hence the MAFT. I can't just lose it, because I have nothing else to fall back on.

I'm using Castrol GTX Conventional 10w-30.

I will definately have to get into the engine, that's a given. Just driving it along again won't "break it in again" whatever will still be wrong with it.

to add, I just feel like giving up.

 

[jdub]

I re-read your post and did an edit...see above.

Dude...with this or any motor sometimes shit happens. Granted, the break-in was not textbook, but it should not have caused the #1 cylinder to go out like that. You may have a bad piston or rings set. The only way to know for sure is to pull it.

If you do pull it, I'd like to know what you find. And, use straight 30W dino oil for the next break-in.

 

[gixxer750]

lean it out, drive it around about 300 miles, then take it to the dyno and get it tuned....

 

[gixxer750]

I re read that too.... before you tear it down, do a real compression test on it.

I don't know about the ross rings, but the wiseco's you have to make about 10-15 boost pulls before the rings seated.

 

[RacerXJ220]

lean it out, drive it around about 300 miles, then take it to the dyno and get it tuned....

with the compression like it is, I don't know if it will help to have it leaned and then drive it around.

I want to lean it and beat hell out of it I'm so JOLLY PISSED.

Edit: my question, does driving this around more help the situation after I lean it out??? I would guess not, but seriously?

 

[cadman]

I'll add a nutral statement, just because most everyone knows this. Do not break in a motor with Synthetic oil. It will not break in properly. Most people do know this though...

The other thing I read there was, you rebuilt the motor, then left it for 1 year? Is that a true statement? What had you done to break in the motor before you left it alone for 1 year? If you build a motor up new, and then leave it without starting it for a year, that's not good.

I know a guy who had build a 351C for his Mach1. He did everything new. New block, new pistons, rings, the works. He put oil, and then turned the crank for a while to get the oil around a little. That was the last thing he did. 5 years later, he had never started it. That motor was seized.

Could be things started rusting. But please check and make sure, this is just a suggestion, and infor on what I've heard other people say. I don't know these things for a fact.

 

[JustAnotherVictim]

with the compression like it is, I don't know if it will help to have it leaned and then drive it around.

I want to lean it and beat hell out of it I'm so JOLLY PISSED.

Edit: my question, does driving this around more help the situation after I lean it out??? I would guess not, but seriously?

I think he's hoping it might help the rings seat.

 

[jdub]

I think he's hoping it might help the rings seat.

That's what I was hoping too...needs to do a real compression test like both of us said.

 

[cadman]

Yeah, if you lean it out a little, run it from idle to about 3000RPM, varying the RPM between that first parked, then in gear with a bit of a load on it, it could help the rings seat. If you're going to take the motor appart anyway, this isn't a bad idea.

 

[RacerXJ220]

I think he's hoping it might help the rings seat.

I'll definately try it when I do WOT the hell out of that motor.

I need to relax a little bit. Things don't tend to upset me, but this.... oh this.... I've owned a supra for 8 years, and damnit do they piss me off.

This is the most upset I've ever been, after a great rebuild.

The motor was fine when I first started it up and started driving it around. I put about 150 miles on it before i noticed the smoke.

THE OLD OIL SMELLED LIKE GAS.

 

[cadman]

I'll definately try it when I do WOT the hell out of that motor.

I need to relax a little bit. Things don't tend to upset me, but this.... oh this.... I've owned a supra for 8 years, and damnit do they piss me off.

Been there man. I think I speak for all of us when I say we're here for you, and understand your frustration. I get the same way. Walk away a little bit, watch some racing vids, read some tuner mags, and then get back in the game.

 

[Racefiend]

If you really are running pig rich, then that may have been the cause of your troubles. You don't want to run rich during the break in as it will "wash" the oil away from piston walls/rings. This is bad during break in as the piston rings need to wear into the cylinders. Without proper oil, you will cause excessive wear, maybe even to the point of trashing your rings under extreme circumstances. Thats why I always insist on breaking in an engine in stock form.

 

[jdub]

THE OLD OIL SMELLED LIKE GAS.

If you really are running pig rich, then that may have been the cause of your troubles. You don't want to run rich during the break in as it will "wash" the oil away from piston walls/rings. This is bad during break in as the piston rings need to wear into the cylinders. Without proper oil, you will cause excessive wear, maybe even to the point of trashing your rings under extreme circumstances. Thats why I always insist on breaking in an engine in stock form.

Yeah...after reading Racer's post above, I'd say that might be pretty extreme :aigo:

 

[Supra]

What did you use for a ring end gap?

 

[RacerXJ220]

Alright, so I got an AEM wideband the day before yesterday, installed it, and went for some tuning, even with the blowby in the crank. I'm so sickly rich, it's killing my car. The Walbro is hardwired to the battery, my fuel pressure regulator was set too high, so I lowered it to 23 with vac on.... When I say rich, I mean rich, so much that I left clouds of black smoke under WOT and the AEM wideband stopped measuring because it stopped at 10...

Now it's almost normal, except under boost. It's weird. The car is below 10 a/f in third, and fourth WOT full boost (12PSI), but in 5th, at 3K RPM I run lean into the 14/15 a/f ratio. What can cause this??? I can tune out the 3rd 4th gear issues with the SAFC, but what about 5th? ADD fuel? Would a fuel pressure regulator issue cause this in the longest gear?

I'm currently at about -12% for high throttle from 2000-6000 RPM and still go into the 10's for a/f sometimes.

Third gear is the gear I'm using for all the tuning runs, we found out about the 5th gear symptom when I got happy foot. The turbo does lag a bit, and I get full boost at 3500RPMs but if I "load" the turbo slowly by starting the run at about 2500RPMs and it has time to build pressure the A/F is good, but if I start the run from 4000 RPMs I get the boost quick, and that's when I run leaner, into the 13's and I hit a 15 A/R once... It's fickle at best, and I want to know what you think is causing this particular problem. I'm guessing it's a fuel pressure regulator not responding fast enough, or maybe the fuel dampener, I'm not sure.

When the boost is on, it pulls like crazy and I hit FCO at just above 12PSI on a turbo made for 18+PSI...
I tried leaning out the pulls not by taking more fuel away with the SAFC, but by upping the boost, hence fuel cut. Now I have a MAFT and I think I can change the FCO point. I have a FCD, but no way I'm using that again. I setup the MAFT per instructions, and I guess I am still missing the FCO part.

And I still have a little blow by.

Thanks for the help.

 

[supramike7m]

THE OLD OIL SMELLED LIKE GAS.[/QUOTE]

damn that is extreme, be careful this can lead to rod knock, by washing oil from your bearings, and thins the oil. ask me how i know. :3d_frown:

 

[RacerXJ220]

Yes, I know. It has been changed few days ago. So any new input?