Sr20det, possible timing issues/sputtering

[JoshWa808]

Hello everyone,
So, I'm nearing my sr20 swap and am having some issues. The engine, when coming back doen to idle, sputters a bit, then settles back into idle. Also, with a quick blip of the throttle, it will sometimes bog down almost till it dies.

Diagnosing the issue I have checked the tps and
Confirmed it to be in good working order. I checked the mechanical timing and it was a tooth off. I moved the timing chain over to make the timing marks line up properly. I've checked for boost leaks and have not found any. Used soapY water 2-3 times And use sterner fluid 2 times over all couplings and fittings between turbo and intake manifold. I've check all injectors and am getting fuel in all 4. Also checked for spark in all cool packs and replaced spark plugs.

I've searched and searched google and while I've found some similiar issues, none of their solutions have worked.

Also, setting timing, I've read
Multiple ways to set this, which is somewhat confusing. Anyone know the 100% correct way to set this.

I am not a mechanic, this is my first swap that is this involved. Any help would be greatly appreciated. Thanks, Josh

edit: parts list
sr20det
e6 ecu
aeromotive fpr set to 37 psi
s14 turbo
cxracing fmic
synapse synchronic bov to atmosphere with anti stall kit(I noticed air coming out of it, don't know if this is normal or not?)
if any other parts should be listed, please let me know.

[TheRealSy90]

Ten bucks says that it has a vented to atmosphere bov, and not recirculated to the intake as it should be.

[JoshWa808]

Ten bucks says that it has a vented to atmosphere bov, and not recirculated to the intake as it should be.

So, I running a synapse synchronic, and yes, it's vented to the atmosphere. But I also have had 2 friends run the same exact setup with no issues like this.

[TheRealSy90]

Okay, the ecu is looking for that metered air that is exiting the bov and becomming un-metered air. This is an all too common issue.

[JoshWa808]

Okay, the ecu is looking for that metered air that is exiting the bov and becomming un-metered air. This is an all too common issue.

ok, ill get it recirculated and see what it does. by any chance, could I remove the bov, cap the flange and see if it still sputters? would that work? I know it would have some turbo flutter but minimal shouldn't be too bad, id think

[TheRealSy90]

You could do that with no problem to see how it affects it. Would be the same effect as recirculating.


Sent from my iPhone using Tapatalk

[zupabpoor]

You could do that with no problem to see how it affects it. Would be the same effect as recirculating.http://goo.gl/feCCP2

[JoshWa808]

You could do that with no problem to see how it affects it. Would be the same effect as recirculating.


Sent from my iPhone using Tapatalk

ill try and get to it today at some point, thanks

[JoshWa808]

so I took off the bov, capped the hole and its still sputtering. also i forgot to mention. it doesn't go past 5psi when in boost

[the head]

Download the SR FSM, check the timing.

Is the IACV hooked up and functioning properly?

How much pressure did you run doing your boost check?

Fuel pressure may be the issue, start the car and let it idle, unhook the vac hose on the FPR and then set to 43.5 psi, then hook hose back up.

[stigo]

Try cleaning the iacv or adjusting it with the top screw? Recirculating BOV helps a lot btw might want to do it anyway.

[KoukiMonsta]

You say tps is 'in good working order' - Did you actually test the voltage?

Read this, it's extremely useful...

http://www.plmsdevelopments.com/sr_setup_tips.shtml

[JoshWa808]

The boost leak test I did was while the car was running. Today I did make a proper leak tester and tested it with about 8psi through the pipes starting from the intercooler pipe that connects to the turbo. I also set the fpr like you suggested to 43.5 no vacuum.

I am going to check timing again, what is the best way to do this? I've read different ways and am not sure which is the best. Also I tried checking for codes on the ecu but the led appears to not be working.

When I assembled the intake manifold, I put a new iacv gasket an it looked pretty clean.

I need to order material to recirculate the bov.

Also tps was checked with a multimeter, set at .5v throttle closed, when opening it, voltage ramped up smoothly to 4.17v at wide open throttle

[Kingtal0n]

Ten bucks says that it has a vented to atmosphere bov, and not recirculated to the intake as it should be.

Im with this guy. Disconnect, and Block the bypass with a huge sock and tape it over, AND disconnect the wastegate arm (the metal rod) then see if your idle problems go away.

If you got no boost leak, and you got no atmospheric bypass, that leaves: the maf is too close to the turbo. Air flowing backwards through the turbo (compressor side) does the same thing as a leaky atmospheric bypass valve when the maf is close to the compressor (within about 2.5 feet on a T-28). Which is why I said to disconnect the arm (before anybody questions my fuzzy logic).

On my car when I lift without a bypass my a/f goes to 10:1 also with the arm connected, and barely moves from 14:1 without it connected, as experimental evidence support. The fix is two fold: move the maf away from the turbo (we should be doing this anyways) and run a recirculated push-type bypass on the hot side as close to the compressor as possible.

or just go PFC D-jetro and learn to tune a MAP sensor... gg

I am 95% confident your problem is NOT: [IACV, TPS]
you can disconnect both on your engine and it will still run somewhat normal!

[JoshWa808]

I took off the bov and capped the hole. It still did the same thing. The maf is pretty much in the stock location.
http://i439.photobucket.com/albums/qq115/rocksteadily/6C809E24-B6D4-4E72-911F-196D8621380F.jpg (http://s439.photobucket.com/user/rocksteadily/media/6C809E24-B6D4-4E72-911F-196D8621380F.jpg.html)
Here you can see where the filter is. Pretty much stock location. I am really struggling to get the timing set right. I've gone back and forth adjusting the iacv and cas. The car feels wry underpowered. And chokes a little between shifting. Also looked at the cams, as the previous owner said he wasn't sure if they were stock. The only numbers I found on them were on the exhaust side. There was a "BA2JWA" on the front side of the cam and a "10" casted into the metal on the rear of the cam. Does anyone know these? I've googled and came up with no results

[cotbu]

Try moving the mafs further away from the turbo, also it'll help when, if you decide to recirculate the bov. Do you have any codes, not check engine light but fault codes stored in the ecu. Search how to pull codes.

Ign Timing is set with a light, no guess work there's no need to struggle with anything.

Sent from a Highly Tuned Note 4.5!!!

[Kingtal0n]

the picture is highly incomplete. i dont see any hose clamps or anything. Did you fill the plumbing with 15psi from an air compressor to find leaks?

computer works with:
maf voltage -> fuel injector pulse

need a tight seal to get a good maf voltage. Also the maf must be placed far from the turbo because the whipping action of the compressor wheel buffets the maf sensor. (it delinearizes the rate of movement of the incoming column of air, which is required for steady incremental voltage)

example, ecu "sees":
1.254
1.254
1.247
1.242
1.247
1.242

During compressor surge at idle speeds, you would "see" something like:
1.254
1.878
0.698
0.774
1.787
1.115
1.747

remember the ecu can most likely sample several thousands of times per second so this example is dramatically escalated.
When the numbers become inconsistent the fuel pulse does as well, and they are randomly oriented to idle state conditions if the engine is at low speed.
A stock T-28 sr20det can surge at a high idle audibly.

[JoshWa808]

Try moving the mafs further away from the turbo, also it'll help when, if you decide to recirculate the bov. Do you have any codes, not check engine light but fault codes stored in the ecu. Search how to pull codes.

Ign Timing is set with a light, no guess work there's no need to struggle with anything.

Sent from a Highly Tuned Note 4.5!!!
I have been using a timin light but for some reason it never seems to be consistant.also when I get it to 15*atdc it feels like the timing is retarded. very laggy feeling. also, ive tried to pull codes following procedures found online, but im prett sure the led in my ecus( ive tried two lol) are both burnt out. is there a way I can replace the led?
the picture is highly incomplete. i dont see any hose clamps or anything. Did you fill the plumbing with 15psi from an air compressor to find leaks?

computer works with:
maf voltage -> fuel injector pulse

need a tight seal to get a good maf voltage. Also the maf must be placed far from the turbo because the whipping action of the compressor wheel buffets the maf sensor. (it delinearizes the rate of movement of the incoming column of air, which is required for steady incremental voltage)

example, ecu "sees":
1.254
1.254
1.247
1.242
1.247
1.242

During compressor surge at idle speeds, you would "see" something like:
1.254
1.878
0.698
0.774
1.787
1.115
1.747

remember the ecu can most likely sample several thousands of times per second so this example is dramatically escalated.
When the numbers become inconsistent the fuel pulse does as well, and they are randomly oriented to idle state conditions if the engine is at low speed.
A stock T-28 sr20det can surge at a high idle audibly.
that picture was taken during the swap. just to show intake placement. the intake length is abot 16" with a hard "s" bend. ill try to move the maf further forward but its really tight for space. as far as intake filter size, is there a size limit? I do have 3"X3.5" k&n cone filter I can use to free up space but I don't know if that filter size is sufficient.

[JoshWa808]

.

If you got no boost leak, and you got no atmospheric bypass, that leaves: the maf is too close to the turbo. Air flowing backwards through the turbo (compressor side) does the same thing as a leaky atmospheric bypass valve when the maf is close to the compressor (within about 2.5 feet on a T-28). Which is why I said to disconnect the arm (before anybody questions my fuzzy logic).
!

im confused as to how you can get 30" of intake pipe in here haha I have abou 16-17" and its a very tight fit

[Kingtal0n]

im confused as to how you can get 30" of intake pipe in here haha I have abou 16-17" and its a very tight fit

Oh no, I was no suggesting you add so much length. The idea here is to fix the real problem: low speed compressor surge. You can run a maf fairly close to the compressor and the idle will be rock solid... IF you can get a push-type (like a greddy type-s or HKS race) recirculated bypass, on the hot-side, really close to the compressor, to hang open at idle.

the open bypass at idle will prevent the pressure from trying to increase right after the compressor wheel, which is why it will surge so easily at low speeds.

also I have never heard of an LED burning up in an ECU before. hmm.

well as to the timing. this could be a big problem. you need to get it right, for sure. Many Timing lights will show two different results because the pickup is directional. You need to make sure the CAS is nearly centered between the two bolts (the nut is almost center on a well timed car). The timing light should be giving a rock solid 15* btdc, and if it isnt, reverse the pickup. You should use the middle wire on the cylinder #1 coilpack to take the reading.

[Kingtal0n]

http://i9.photobucket.com/albums/a90/kingtal0n/Kingtal0ns_240sx_2/P1200499_zpsn7teaftx.jpg (http://s9.photobucket.com/user/kingtal0n/media/Kingtal0ns_240sx_2/P1200499_zpsn7teaftx.jpg.html)

[JoshWa808]

Oh no, I was no suggesting you add so much length. The idea here is to fix the real problem: low speed compressor surge. You can run a maf fairly close to the compressor and the idle will be rock solid... IF you can get a push-type (like a greddy type-s or HKS race) recirculated bypass, on the hot-side, really close to the compressor, to hang open at idle.

the open bypass at idle will prevent the pressure from trying to increase right after the compressor wheel, which is why it will surge so easily at low speeds.

also I have never heard of an LED burning up in an ECU before. hmm.

well as to the timing. this could be a big problem. you need to get it right, for sure. Many Timing lights will show two different results because the pickup is directional. You need to make sure the CAS is nearly centered between the two bolts (the nut is almost center on a well timed car). The timing light should be giving a rock solid 15* btdc, and if it isnt, reverse the pickup. You should use the middle wire on the cylinder #1 coilpack to take the reading.

http://i9.photobucket.com/albums/a90/kingtal0n/Kingtal0ns_240sx_2/P1200499_zpsn7teaftx.jpg (http://s9.photobucket.com/user/kingtal0n/media/Kingtal0ns_240sx_2/P1200499_zpsn7teaftx.jpg.html)

so can the synapse bov without the antistall kit, recirculated to the intake pipe just before the compressor work?

[JoshWa808]

So I haven't had a chance to recirculate the bov, but I did bypass it with no change. Another thing, the wire harness I bought, I don't know the specific year it's from. Could it be an issue with mismatched harness/ecu?

[JoshWa808]

Bringing this back up, I recirculated the bov, it mad no difference. Replaced tps sensor, knock sensor, used a brand new wiring specialties harness, tried a different ecu. The car idles okay. But under load, bogs and sputters and has zero drive ability. Talked to the person I bought the engine from, and he says it could be the lifters. He told me that they are Intec racing lifters and people have had problems with them? I'm not sure. At this point I can only imagine that something is wrong internally. Also, did a compression test, results are, front to back, 180,155,150,155. Leak down test shows about 10% leakage and can be heard through both intake and exhaust, and heard in the oil pan.

[zombiewolf513]

Those are bad compression tests results. you have a 30 psi difference between highest and lowest.

[!Zar!]

180psi is abnormally high.

150~155 sounds correct.

[Kingtal0n]

Bringing this back up, I recirculated the bov, it mad no difference. Replaced tps sensor, knock sensor, used a brand new wiring specialties harness, tried a different ecu. The car idles okay. But under load, bogs and sputters and has zero drive ability. Talked to the person I bought the engine from, and he says it could be the lifters. He told me that they are Intec racing lifters and people have had problems with them? I'm not sure. At this point I can only imagine that something is wrong internally. Also, did a compression test, results are, front to back, 180,155,150,155. Leak down test shows about 10% leakage and can be heard through both intake and exhaust, and heard in the oil pan.

tuning, boost leak, timing

lol lifters? Who changes out OEM Lifters for something else? thats weird.
and yes you need to see 150 150 150 150 with minor variance

so: if the compression is good, motor sounds good no knock, oil looks clean then: tuning, boost leak, timing