Stuttering and stalling under boost after fmic, built head with 272's, o2 housing

[96gstdsm]

Got my car back and now when under boost it stutters a bit. It will also stall out when I come to a stop sometimes. Sometimes it will idle fine, other times it will start dropping and then shooting up to like 1500 then back down to 300 etc till it dies out.
When I got to really get on it a bit and it gets into boost it will hesitate and stutter first then get into boost and be ok. Just pretty much the initial getting into boost that stutters bad.
I think the idle is set around 800 or so. Seems to switch depending on how long it has been on so hard to really say. Kinda switches between 750 and 1000 when not dying out.
Would untuned cams do this? I also have some skunk 2 adjustable cam gears zero'd out.
My car did not have any idle problems after I got a 6 bolt block put in with a 190 pump rewired. I then brought it back for the rebuilt 7 bolt head with bc 272's, o2 housing, front mount, and a 3" downpipe and it has been happening since then. I have been monitoring everything with ecu+ so I can datalog if that would help finding out what is wrong.

Any suggestions would be great.

 

[oldman]

Yeah could be. So I should turn it the other way to correct that or no?

Like I said, you can't just go and turn it, you need a scan tool to do this on a 2G. If you don't have a scan tool, adjust it with the car off, turn the car on and check your idle speed as well as monitoring your ISC, not only you want to be idling at 750, you also want the isc to idle at 30. Turn off the car every time you need to make adjustment. That said, none of this should be done until you fix all leaks or you will have to re-adjust again.

Also is talking about your experiences with a dsm shop good or bad allowed on here?

It's not allowed, post it here, http://vendors-reviewed.com, for the whole world to see.

On another note would low oil pressure according to the stock gauge most likely mean a bad oil pump? The oil pressure is much lower than it was on my old engine. The 6 bolt engine I got now the oil pressure during idle is around the bottom line, maybe a little bit higher, and then when driving gets up to around the middle line. Haven't had time yet to hook up my oil pressure gauge so just wondering how horrible the stock gauge is and what numbers at those points could mean.

I wouldn't trust what the stock gauge have to say, hook up your oil pressure gauge asap. What exactly was done at this shop anyway?

 

[FlatBlackTerror]

Like I said, you can't just go and turn it, you need a scan tool to do this on a 2G. If you don't have a scan tool, adjust it with the car off, turn the car on and check your idle speed as well as monitoring your ISC, not only you want to be idling at 750, you also want the isc to idle at 30. Turn off the car every time you need to make adjustment. That said, none of this should be done until you fix all leaks or you will have to re-adjust again.


It's not allowed, post it here, http://vendors-reviewed.com, for the whole world to see.


I wouldn't trust what the stock gauge have to say, hook up your oil pressure gauge asap. What exactly was done at this shop anyway?

is your maf hooked up? Sounds exactely what mine did when i left my maf unhooked.

 

[oldman]

is your maf hooked up? Sounds exactely what mine did when i left my maf unhooked.

Yes, my maf is hooked up and I don't have any problems.

 

[96gstdsm]

Like I said, you can't just go and turn it, you need a scan tool to do this on a 2G. If you don't have a scan tool, adjust it with the car off, turn the car on and check your idle speed as well as monitoring your ISC, not only you want to be idling at 750, you also want the isc to idle at 30. Turn off the car every time you need to make adjustment. That said, none of this should be done until you fix all leaks or you will have to re-adjust again.


It's not allowed, post it here, http://vendors-reviewed.com, for the whole world to see.


I wouldn't trust what the stock gauge have to say, hook up your oil pressure gauge asap. What exactly was done at this shop anyway?

I got a rebuilt 6 bolt(built by someone else) installed along with a big 16g turbo, fidanza flywheel, 190 fuel pump rewired, motor mounts, mitsu mls, arp head studs. That was the first time around. Got it back was burning coolant 100 miles later, was good for the drive home but that was about it.
Brought it back, said it wasn't there fault was a bad head, I asked them originally to resurface the head, they didn't. So sent the head out to be rebuilt with bc 272 cams, 5 angle valve job upgraded valve train etc. They installed that again with a composite oem head gasket, ssac fmic, 2.5" o2 housing, 3" downpipe.
Besides the head gasket issue there didn't seem to be problems the first time around , but now after the other things have been all installed there are tons of problems. Hopefully nothing serious but still annoying to pay them $2600 to get a car back that has problems.
They for some reason disconnected all my emissions vacuum lines without asking also.
And the valve cover gasket is now leaking also, let along the condition of my paint job haha. Also got the car back and home and noticed there was only 1/2 an inch of coolant in the resevoir. Filled it and has not leaked or gone down at all since.
I just don't know what they could have done the second time to make the idle so horrible and stall out as well as the stuttering problem. It also overheats but I'm sure that is because of the fmic.

 

[96gstdsm]

is your maf hooked up? Sounds exactely what mine did when i left my maf unhooked.

Yeah it is hooked up. I could take a look at it to see if anything looks messed up with it though.

 

[96gstdsm]

Well I checked the tps and that read at idle .69 volts
The plug that was thought to be to the AC compressor is not actually for that. A wire that is attached down the line goes to the AC. Also a wire attached to the CAS runs in the same thing of wires. It appears that it is some how capped off, as there is a clipped blue wire that is routed back into the line of wires.
I checked the MAS plug and on the very left part of the plug it is missing one metal connection. Is it supposed to be there? I know a lot of these plug things don't always have all connectors in each hole.
I checked the MAS input and output and at idle both were at 48hz. Is this normal?

Could the CAS not installed correctly cause the car to sometimes stall out and stutter?
The vacuum line that runs of the end of the fuel rail, that is where the boost gauge is wired into. That is fine right? Had it T'd off that before but since he disconnected the fuel pressure solenoid it has to be run direct now.
One reason why I am wondering about the CAS is cause in my ecu+ management. I have to set the CAS input and output to 90-94 for both in order for it to turn on and not get the misfire code. Obviously having a 96 I would think I have a 95-96 ecu. So according to he program I should put input to 90-94 and output to 95-96
My boost leak tester disappeared so gotta head to home depot again to make another one. Anyone know the inlet outside diameter for the big 16g? Don't feel like taking the intake pipe and all off right now.

 

[96gstdsm]

Just got back from driving. Now it stalls out constantly. Even when moving in neutral. Happened every single time I put it into neutral.
Also when I down shifted it backfired a couple of times.

Taking it to turbotrix in jersey tomorrow to get tuned so just hoping they can get it to run properly as well.
Anyone know there standard tuning costs? Told me originally $250 and just called again and they said it would be $400 Seems really high for dyno tuning doesn't it?

 

[oldman]

$400 @ Turbotrix !!! Nice.....make sure you bring an extra headgasket.

 

[96gstdsm]

$400 @ Turbotrix !!! Nice.....make sure you bring an extra headgasket.

Why you saying that? Anything I should know about?
I have heard good things about them.

 

[oldman]

Why you saying that? Anything I should know about?
I have heard good things about them.

I said nothing, vendor reviews are not allowed.

 

[96gstdsm]

I said nothing, vendor reviews are not allowed.

Can you maybe pm me anything I might need to be aware of? Really don't know where else I can take my car to get tuned. I am not going to ask them to juice everything out of it. Just a good reliable tune. Any other somewhat local places around that do dyno tuning?

 

[oldman]

What size injectors and what are you using to tune? I think Dyno tune is a waste of money since things will always change anyway, I suggest you save the money and buy yourself DSMLink so you can learn to tune and monitor it yourself.

 

[96gstdsm]

What size injectors injectors and what are you using to tune? I think Dyno tune is a waste of money since things will always change anyway, I suggest you save the money and buy yourself DSMLink so you can tune it yourself.

I have fic 650's. I have ecu+ for tuning, I just spent about 9 grand on everything and didn't really want to risk me screwing anything up with tuning as I have never tuned before. I also don't have a wideband o2 yet, so that would be another $300 right now.
Thats really why I wanted to bring it to somewhere I thought was reputable. Seems nowhere is for these cars that I can tell.
They got a wideband for tuning and said they could give it a good reliable tune no problem.

Are there any other good dyno tuning places in the north jersey or nearby ny?

 

[oldman]

So they get it a safe tune now and what are you going to do in the winter, spend another $400? Do they even have much experience with ECU+? If you know nothing of ECU+, why did you choose this route? There are two areas of tuning, close and open loop. Is the shop going to drive your car around for hours on the highway to get your fuel trims dialed in properly? What you will probably end up with is a decent WOT tune based only on AFR without any timing consideration, drivability is probably questionable, you will have no wideband to properly monitor any changes that can occur anytime, even if you do you still don't know how to fine tune it yourself.

My suggestion is to buy yourself a wideband, learn ECU+ or swap out for dsmlink instead of relying on a shop who is make your money by the hour.

 

[96gstdsm]

So they get it a safe tune now and what are you going to do in the winter, spend another $400? Do they even have much experience with ECU+? If you know nothing of ECU+, why did you choose this route? There are two areas of tuning, close and open loop. Is the shop going to drive your car around for hours on the highway to get your fuel trims dialed in properly? What you will probably end up with is a decent WOT tune based only on AFR without any timing consideration, drivability is probably questionable, you will have no wideband to properly monitor any changes that can occur anytime, even if you do you still don't know how to fine tune it yourself.

My suggestion is to buy yourself a wideband, learn ECU+ or swap out for dsmlink instead of relying on a shop who is make your money by the hour.

Well what I most want right now is just to make sure it is really safe to be driving and not worrying about something blowing.
I got a bunch of little problems and I would like them to be looked over by a dsm shop. Thought they were a good shop so I would go to them. Maybe they are not.
I plan on getting a wideband o2 sensor shortly.
How much of a difference will the weather make the tune? Can it change it so much that it will be dangerous?
I spoke with the tuner at turbotrix, and I know it is just talk, but he said they could tune it for daily driving also for WOT etc. I also have adjustable cam gears that they will factor into the tuning. ECU+ also allows you to adjust timing.
Right not my car is hardly driveable as it constantly stalls everywhere and now is back firing and stuttering any time I hit any boost. I have work on tuesday so I just really want to get this in pretty good running condition without worrying about it blowing up anytime soon so I can take it to work and all.

 

[96gstdsm]

Did some more logging.

At idle the timing goes from between like 7 and 14 or so.
Went I stepped on the gas in neutral the timing went up to like 35 at around 4500 rpm's

Also when just idling it said it was under 20% load??
Whats up with that?
Also why would the coolant temps go down when I step on the gas? I have another thread since I have been overheating since my fmic, but figured I would throw that in here also.
They go from like 204* or so when idling and when I step on the gas in neutral it go down to like 197*

 

[92 GSR-4]

Wow, alot of talk on this thread since I last checked.

96gstdsm, it sounds like your timing advance is fine. I get 30*+- at a cruise in all my 1G's. Under load you want to shoot for as much timing as you can without detonation. In my case it's usually 23-25 degrees on my 16G car and around 20 on my GT-12 car. So that's fine. Also, you've checked that the TPS and ISC are functioning correctly? Theres a test you can do that requires a multi-meter. You test the ohm load in the ISC to determine if its in spec or not. I would suggest that for the stalling issue. Does it act like the revs drop and it just can't pick it up unless you pat the gas?
I also agree with oldman about the dyno tune. The only advantage I see is if you don't have a wideband to tune your car with, but before we go tuning it, it needs to run correctly...which they will probably charge you to fix it before they tune it. They could tune your car on a conservative scale to make it operable under all conditions, but you would really want to tune it yourself and monitor the logger constantly to get it to a razor's edge, and squeeze alot more power from it.

OLDMAN, you think maybe the problem lies in ECU+ ? I use DSMlink, and I haven't ever messed with his tuning system....but between a 6-bolt and some possibly "improper" settings in his EMS I can see some problems.... and some adjustable cam gears...crap theres alot of variables here, and some of his problems could be timing related.

96gstdsm, do you have a stock ECU you might put in just to see if anything changes? I didn't catch your injector size but the car would run fine with larger injectors, just sluggish from being pig rich. 550's you probably wouldn't even notice. BTW, from your previous post it looks like your MAF is working right. You raise an interesting point about the CAS. The CAS can be installed 180 degrees out. The only way to tell for sure it to put the engine on time and pull the CAS out to verify the tick mark is where it's supposed to be. But yes, I think the CAS *could* have something to do with stuttering and backfiring. If the CAS was bad the engine wouldn't run at all because of no spark.

Good luck, stay motivated, and keep investigating and testing and I promise you'll beat it into submission!

 

[96gstdsm]

Yeah it wants to stall out and the only way to stop it is by stepping on the gas peddle to try and keep it raised a little bit.
I checked the tps and it showed .69 volts at idle which means that is working.
I don't think it is ecu+ since it was in my car the first time I got my car back and it was working fine, nothing was changed with that so would highly doubt it.
Yeah I wish I could tune it myself, but don't have a wideband or any experience with tuning, and was really hoping to just get someone to give it a pretty solid tune. This is my daily driver and I am going straight from a t25 to a built engine and a big 16g with 272's. So I'm sure even if I don't juice every last bit of power out of it, I will be extremely thrilled with he power gains.
As of now I have the stock injectors in. Was leaving them in until I broke my new engine in.

The thing is the new parts that were put in after I got it back the first time with no idle problems is the built head with the 272 cams, cam gears, o2 housing, fmic and downpipe. Seems like it should have something to do with one of those things.

It seems to idle fine before it is really warmed up. Idles high but doesn't stall. The stuttering happens no matter what. Once I drive it around for a little bit and come to a stop it will try to die out right away. Gotta stay on the gas so it won't.

 

[92 GSR-4]

Man it just really sounds like it could be the ISC, but when you factor in stuttering and backfiring it makes me think its timing related. And did it run good AFTER the 6-bolt conversion?

Have you tried setting the baseline timing advance via the CAS and zeroing the ISC?

 

[oldman]

We have already concluded that you need to properly adjust your BISS after you perform a thorough boost leak test, have you forgotten? Your ISC is out of its adjustment because the BISS is too far out.

Who did the setting in ECU+ to compensate for the 650s if you don't know how to use ECU+? Do you have a link to the manual for ECU+?

 

[96gstdsm]

Man it just really sounds like it could be the ISC, but when you factor in stuttering and backfiring it makes me think its timing related. And did it run good AFTER the 6-bolt conversion?

Have you tried setting the baseline timing advance via the CAS and zeroing the ISC?

It ran fine in regards to bad idle or stalling or backfiring when I first got it back with the 6 bolt block. Then after bringing it back due to a bad head gasket when he pulled it up it idled for a while and then died. He took a screw driver to the biss and then it idled fine again for a little while but a few minutes later after driving it, it stalled again. Seems to have gotten much worse recently. Now once warm it dies out all the time at a stop.

The cams and cam gears I got installed the second time there so could be something to do with that.

I really haven't done anything besides logging it and trying to find something that way. I don't know too much about these cars to trust myself especially after spending like 9 grand on performance stuff for it. Thats why I just wanted to bring it somewhere to get it dyno tuned and hopefully worked out the kinks.

Just worried now after people said they probably would only tune WOT pulls. This is my daily driver, so WOT is not all that matters to me at all.
Want the whole car at all rpm's to feel good and be good as well.

 

[96gstdsm]

We have already concluded that you need to properly adjust your BISS after you perform a thorough boost leak test, have you forgotten? Your ISC is out of its adjustment because the BISS is too far out.

Who did the setting in ECU+ to compensate for the 650s if you don't know how to use ECU+? Do you have a link to the manual for ECU+?

Yeah went to home depot today to get the stuff to make one and couldn't find the right size coupler. So wasn't able to get to that today. I also really have no idea how to deal with the ISC. Can most shops just check that?
Also I am running the stock injectors right now. I left them in for breaking in my engine. Been about 500 miles now so gonna put them in when it gets tuned. I have a 190 rewired fuel pump installed already though.

 

[92 GSR-4]

Ok, well can all appreciate a nice street car. That is why I'm using a smaller BB turbo and mild cams, when I could have spent the same money and went into the 10's. So I know where your coming from.

Oldman is right, the ISC is definately out of whack, and that's the first thing you should fix. You see, you just cant turn the biss screw and set the idle. The biss screw is there to set the baseline idle. Think of the ISC being able to adjust the idle +- 30%, meaning the max it can lower the idle is -30% and the most it could raise the idle is +30%. Thats a 60% spread of adjustment. Now, lets say that your idle is perfectly at 750, but the ISC is at +26% in order to achieve that idle. Now, you only have +4% of adjustability to compensate for things like pushing the clutch in and saving the engine from going below 750. See where I'm going? That is exactly how the ISC works, it is there to automatically allow more or less air in through the throttle body, as needed, in order to achieve your baseline idle...which should be 750 +- 100.

However, I think that after you set your baseline idle, you will still have a stuttering problem under boost. You have your ECU+ set for 450cc's, right?

 

[96gstdsm]

Yeah it is set for the 450's right now. Do you know what you think would cause the sputtering? It only happens when getting into boost. Once I get boosting a little more then it stops sputtering for a little bit and I take off. And then when I slow down and repeat same thing again.

 

[92 GSR-4]

One more thing:
While a wideband is a NICE tool to have, you can still do ok without it. It could be useful in your situation to make sure you have your injectors dialed in correctly, and for the AFR before and during your boosting problems, but you can get past it without a wideband. If anyone told you they only tune at WOT...damn. While tuning is mostly at WOT, you still need to make sure your good at idle and at cruise. In a 1G on a narrow band I usually made sure the O2 was cycling while I was at a 40 or 50 MPH cruise and also at idle. Check your fuel trims as well to make sure they are in check.