Ok might take you up on that Jim. Right now I dont' think its the tune I think its something else. Wire not on plug maye that pesky number 8!
So NicD that sounds interesting. So just un fail the maf and watch misfires .Do i have to plug the maf back in then? I can't drive the car though with the maf in there and the 3 bar map can I ? So could only test misfires at idle or will it even run with 3 bar and the maf in there ?
Sounds better than switching tunes just to check though.
You guys are giving me some good ideas. Will try out some of them.
I can try to send that tune file but as said it can only be read with the 2.23 beta software right now.
My gut reaction is its not the tune.

 

Yes, it needs to have a MAF in place so the maf doesn't fail out and it actually runs.

Why not just post the tune file? Don't worry about it being 2.23

 

Who is actually tuning it ?

 

I have mostly been tuning it Stevie. I have tuned my lt1 non fi and several of my talons which are highly modded fi. I have tuned the 99 with hptuners for several years na and then with maf and fi and now with 3 bar sd .
I have only had the kit running with the 408 for a month or two and didn't really go much into wot until lately.I was waiting on my fuel system to go wot. Then I find this problem.

I have never actually sent a tune have to figure out how to do that. And unless I read the ecu it would be in 2.23 format.

I am going to try a few things in next day or so as was suggested. Will try power balance, misfire maybe like Nicd said although again thought you can't drive the car with maf and 3 bar in there? Or can I just idle it and look for misfires at idle.They might not show up till wot though. I might even pick up a infared temp reader and check individual cylinders they are handy for other things and they are on sale right now.

I really doubt its the tune. I will also check those individual narrowband o2s and see what they are doing.

I appreciate your help and ideas.

As said Steve we have a good hptuner guy here but he said pretty much my car is beyond his experience.So that leaves mailorder or me to muck thru it.

 

As others have said, I'd just go through a basic check and ensure all ignition related components are 100%

If possible, chuck another set of coils on just to try.

Try different gaps, from small to large ( and with a cheapy set of copper plugs )

 

Changing plugs in my car is not something fun to do. My talon is simple to check and change them. I checked a couple recently and they looked fine.Not fouled looking but of course could have fouled one if have cylinder not firing right.

 

Checking a couple is no good. They all need checked.

I once checked mine, and found a broken plug. Strangely the car was still running very well.

If I had only checked a couple..I'd never have spotted it.

If you are trying to diagnose a missfire of any kind, you MUST inspect all plugs.

 

Agree Steve but going to check indirectly first. Check power balance test. And mabye try to get misfire working to check and then it if at least narrows it down to one plug much simpler. I was planning to go to colder heat range next season anyway so that was best time to change out plugs. Dont' really want to go much past 7.5psi on current turbos anyway. Its good enough for the street now.
Back two passenger side are the most annoying ones to check. Pretty sure number eight will have to be done from top don't think can access from underneath.Drivers side and couple front ones on passenger not too bad. My turbos are low down so not in the way. The direct port nitrous lines make it a bit more fun especially on that passenger side.

I know excuses but might as well see if can figure it out indirectly first.

 

I had a similar problem. I pulled all the plugs and found one severely cracked. Car drove fine at night, but if you got on it during the day it would misfire like crazy. I would eliminate the plugs and stop with the full guess mode. You solve problems by eliminating obvious possibilities and work your way down to the less likely.

 

Do you own a tt f body with direct port lines? You truck guys usually have so much room and so easy to get to the plugs. Think Corvettes are also much easier. These fourth gens suck for plugs, suck for valve spring changes..

Guys, its not that easy to get to all the plugs. Some are going to be really not much fun. I don't think it would be guessing by running misfire or power balance first and see if that finds a bad cylinder. Easier to pull one plug than all. The plugs are also nearly new so less reason to check them all. But agree have to do it as part the deal if the misfire or balance or possibly infared gun don't find anything .Also will do the check my o2s and see if one bank is funny. At least that could narrow it down and hopefully its the drivers side that bank is easier to do the plugs on if it is a plug.

 

Did a bit more stuff on car today. Redid my tune with 2.22 non beta hptuners so didn't have to put 2.23 back in at all. I did the power balance test and all 8 cylinders were very close to each other.
I think put maf back on car and turned it back on. Have 3 bar map still on the car. Wasn't sure if should drive the car with it like that??? The car started and idled ok. I then could check misfires. They were very little and nothing stood out on any one cylinder and revved it up to 3000 or so and saw nothing funny.
We also blocked off intake to stop maybe oil coming thru the line into the intake .
Put breather on the valve cover for now .
Took car out for some test and tune .It was hard to lean on it as too much traffic around even in industrial part of town. Still we got it up there but didn't really keep it in wot or hammer it wot.
Timing I think was set at 15 degrees max. Running e10 94. 9.5 compression.
Saw no knock at all. Didn't get around to checking both o2s at same time. Laptop was dead those things just don't seem to last long should get lighter adapter.
Car didn't seem to be doing it think quite as bad the machine gun wot noise.
My copilot a pro racer but a carburetor or antique fuel injection guy seems to think maybe I need a lot more timing like 20 degrees or so. Since running only low boost 7.5psi. I am not running any alc or meth so not sure if that is ok .Of course can take it up gradually and see if the machine gun stops.He things it could be really retarded wot or maybe other theory is turbo is putting out some oil ,pretty common with the aps and without an added scavenger pump and that is igniting in the exhaust.Does that make any sense?
Could my timing be way low at wot. Expecially at say 3000 rpm where usually hammer it in third for these tests.
I am still resisting pulling all the plugs but will if need be. I was planning to pull them all in the off season when car is not driven and then would be changing them to couple heat ranges colder when install the bigger turbos . I really wasn't planning to push the current ones much past standard gate pressure. Just want them to last me till car goes away end of october.
So can timing give this effect at wot? I also reset my stock in my tune to 14.13 for the e10 and have PE at 12.8 and boost pe at 11.2. Don't think am too rich .Ve has not been dialed in yet though.

 

a solid timing figure will not cause it.

oil from a turbo wont cause it

Even silly mixtures are unlikely to cause it.

An ignition problem could very easily cause it.
Have you confirmed the timing you request via the ecu, is what you are getting at the engine with a timing light ? At various rpm's

Are you logging any crank or cam sync errors ( if you can do this...which I'd assume the stock ecu can somehow ? )

Have you logged all sensor inputs, and looked for any anomolies during the problem ?

oh...and have you removed and throughly inspected all spark plugs yet ?

 

I hate to be the one but the <machine gun affect> I got that on my speed density tune and it was a boost leak not a bad one I notice my boost guage wasnt working pull over and stop replace the line clamp srove the car tried to go intoboost watching the afr it started to go lean. Pull to the side again shut the car off waited 10 mins started it up and everything was fine. Not saying it will fix yours but this is what happen to me. Also Im with the plug on this one I learn it dont take much to fudge up a plug.

 

Only the 1. Man you want to come take them out be my guest. Its a pain on my car especially the back ones on passenger side. I don't want to simply take them out to look at them. I would put in colder heatrange at same time. Either one or two heat ranges colder since be upping boost likely for next spring and might start hitting it with some small shots of spray once have all this other stuff figured out.

I guess am trying to avoid checking all the plugs. Man its 5 minutes on my 97 talon and this car is such a pain. I know I know..quit making excuses..

So post above says boost leak did cause it..can boost leak cause it in speed density thought it can't?

Only in draw thru setups..??

 

I think it would be a lot easier for you to pull the plugs, than for me to catch a flight several thousand miles to do it

Consider this. If it is plug related.....you'll be spending hours ******* about with other stuff, wasting fuel testing, pulling your hair out....and all because its a bit of hassle to rule out a quite important component.

the post above suggests he had a problem, and he says a boost leak ( somewhere ) may have caused it.

Is it the same as yours ??? well, who knows really. And you say you've already tested for leaks.

You said there were none ?? So did you test or didnt you ?

Keep it simple, work through it one step at a time. Starting with the plugs/ignition system

 

I smoke machine tested the car. Found no leaks. But not 100% sure that smoke machine would find a leak under boost. It did find some leaks on my 97 talon though quickly.
The old fashioned way of course is to make boost leak tester hook up compressor .Have done that in past on my talons.
But smoke just seems so much easier .Great for finding vac leaks, exhaust leaks..etc too.

So you are still saying if the timing is way low at wot it won't cause misfiring. Like if put in 8 degrees max..? That would start to almost cause antilag effect wouldn't it?

If too low timing is not going to cause the issue then it is starting to look like it would be plugs or wires. As said the wires are nearly brand new top of line granatelli high temp wires. The plugs are nearly new ngk tr6ix iridiums and were gapped down to .028 or .030 range. I would think they would easily fire at 7.5psi. Maybe gaps are too closed down?
If did have a misfire wouldn't it show at idle or when revved it to 3000 or so at idle?
Wouldn't power balance test show a cylinder that wasn't firing ? No noticeable miss and car is pulling very high vacuum near 20 inhg and steady as a rock.
Car is rich though on decel ,have it ok on idle now but decel still rich. Could this keep foul up the plugs?

I guess time to figure out how to post up the tune. Never actually did it.Have to put onto my flash drive and then into my pc and then post it here..not that great with some of this computer stuff.I am an old hotrodder 51 to be exact.

And Stevie was of course kidding about you coming over and checking my plugs. Drivers side are pretty easy ones to do and front two on drivers are not bad. back one on passengers pretty sure have to go from top and there is nitrous lines and stuff back there now so it might not be too much fun. I put them in when had engine out of car.
Headers used to make the back plugs pretty easy to do from underneath the turbo on the passenger side makes that pretty much impossible to do from underneath I think.

 

More driving ,leaned out afr and put in some timing. Took it to 11.8 and took timing up a bit higher to 20 max. Seen a few degrees of knock retard nothing major.
Car is still doing exact same thing .But this time got mad at it and put it wot in third at 3000 machine gun defintely sounds like coming out the exhaust and car don't pull when its doing this. put it in fourth at couple thousand rpm. wot ..same thing..fifth same thing at like 1500rmp and sixth didn't try but sure it would do that for sure. On way home on highway in fourth punched it at 3000 or whatever and same thing. Now it did this when not even in boost in the various higher gears.1st gear you can get away with not wot and get it go up to redline. 2nd pretty much same. But wot it in pretty much any gear at any rpm and its same thing. So dont' seem to have zip to do with boost. Yet car seems to idle ok. Misfires as said sitting there and up to 3000 sitting there in neutral show zip. Engine pulls 20 inch vacuum steady.
If really feels almost like you are lugging engine in sixth feeling.
Very strange.

I am mad at it and might let it sit for a week or so. Heck might sell it!
I will post tune and see if there is anything glaring there.
Spark can't be blowing out at these low rpms when it does it. And can't see it being a bad plug .
Would bad plugs do this at really low rpms like 2000 in fourth?

 

Ok never did this before..hope it works..Its in 2.22 format now not 2.23.I redid it a bit.

 

For an FI engine....YES. In 4th gear you have a lot of load on the engine, so it can produce boost at that low of an RPM. Not sure the aversion to changing plugs. It would be a hell of a lot easier than pissing in the wind with trying to fix a mechanical defect through tuning. Just my $0.02

Good luck to ya'.

 

Post a log also (with the described symptoms).