linkdeezie

Hey guys. I need some help with this one cause it's never happened to me before and I can't figure it out. And before the trolls start with their comments, YES, I have searched and read and investigated the forums, as well as Googled my *** off. I sit behind a desk 8 hours a day, so it's not-a-thing for me to utilize the search button/engines, but I'm not finding the answer. I have a b16 built for boost. Greddy b series turbo kit. 550cc injectors. Hondata v3 w/ bluetooth. The problem I'm experiencing is that under load, the car is NOT moving. Its barely trolling along. It IS boosting so I know its NOT a boost leak. As a matter of fact, I gunned it down the block and the boost gauge shot to 15 psi (signal source is the intake manifold), but the car feels as if its only pushing 2 psi. You can HEAR the turbo screaming as the car is going down the block. I've checked everything and cant figure out the issue. The ignition timing as well as mechanical timing is dead on. All injectors firing properly. 125 psi across the board on the compression check (low comp pistons). I've checked the plugs, couplers, everything!. This isn't the first turbo honda I've built (its actually the 3rd...maybe 4th...or 5th..kinda lost count LOL) but I've never had this happen before. I was considering replacing the stock MAP sensor with a Hondata one just to see if that was the issue. But the stock map sensor shouldn't prevent the car from boosting properly at 5lbs, so I'm looking for any insight,suggestions, or experiences such as this that any of my fellow HT'ers might have.

K7-1Ktrevor

Txdragon

Agreed with above with timing issue. I had an identical issue with my old Nissan CA18 and turned out to be a bad cam angle sensor. Check there as well..
My question is: how are you reading 15 psi in Hondata on a stock map sensor?

JRCivic1

He is not reading it at the MAP sensor/datalog... the OP said the GAUGE reads 15psi.

OP, when was the car tuned ??? Has it run properly before and now has issues or has it always been this way ???

Balor_Gr

Ghetto guessing:
Do you have CAT on the car?
Do you did a leak test on the charge piping? Turbo WILL make whatever target boost even with a big leak.
It WILL overcome the boost leak unless the leak is huge. It just uses ALOT more exhaust energy wastegating less gasses. This will rob a lot of power.
Who did the tuning? Is the ignition advance normal in the program?

linkdeezie

I though about the cam timing. and rechecked it yesterday. it is spot on. Its an old tune that im actually using for a basemap. I built a Si 2 years ago and kept the tune. Sold the car. Now building the same set-up again, but this time in an EF as opposed to an EM1, so I used the old tune for the basemap. Havent even gotten it to the dyno yet because of this issue im having. And no, im not running a missing link. havent done that in at about 15 years LOL

linkdeezie

I'm not reading 15 psi in Hondata on a stock map sensor... where'd ya get THAT idea from? As far as the cam angle sensor, it's possible. I AM using some sort of aftermarket distributor (obd1), and if I'm not mistaken the cam sensor is actually built into the distributor, unlike obd2, where it is an external piece. The ignition timing is fine tho, but I guess I can swap the dizzy and see if I get anywhere

linkdeezie

It's always been this way. Engine has MAYBE 15 miles on it from driving around the neighborhood. The car itself hasnt made it to the tuner. I'm running an old tune I had for my Si (EM1). Even with a basemap, the car should at least have a LITTLE go. It's an EF. Weighs nothing.

Txdragon

That's a good first start.

linkdeezie

No cat. Test pipe.No leak test. If the gauge (and s300) wasnt reading boost, then I WOULD test it. But my source signal for the boost is the intake manifold (for the gauge) and for the s300, its the MAP sensor, which means it IS seeing pressure, so at least SOME of that pressure should be transferred into the engine head, especially @ 10 psi. The ignition advance is normal until boost, in which it begins to retard the timing. its just really mind bogging to me because i NEVER had this issue EVER before. I was thinking maybe its something with the car itself seeing as how i've never owned an EF, but I dont see how it could be, unless it has something to do with the obd0-to-obd1 conversion

TheShodan

iTrader: (14)

It's good that you have the boost gauge hooked up to the intake manifold. That's the best source to see if you're ACTUALLY getting boost pressure, as opposed to strictly reading it from a laptop that sees the map sensor.

I'll make the presumption that this car has been properly tuned (is that a fair assessment? If not, and you're running on a basemap, this could pose a problem.)

What's important is whether or not the kit you've installed ALWAYS had 15psi of boost pressure, and the symptoms recently started, or if you've just now put this together, and it NEVER got to 15 psi.
-Is the kit new, or used? what was the condition of the turbocharger whence you obtained it?
-Was there anything recent that happened to the car before putting this kit on? Any overheating, or rebuilding of the engine required before installation?
-Which turbocharger are you using? the TD04-15G or the TD05H-18G? This makes a difference...

At this point I'm looking to vacuum setup on the wastegate, boost control, vacuum sources and possible leaks that can't be seen through a leak tester (MAP cars don't give the same results as MAF cars like Subarus), or possibly turbocharger damage.
More information is needed at this point, and this is beyond a Google search. This is physically understanding how you've set the car up.

Balor_Gr

My man thats what turbo does. Overcomes leaks .You can say the engine swallowing air is constantly trying to create a leak but turbo overcomes it and creates boost.
On hondas many times you dont hear the hissing sound of a leak.You can make some holes on the charge piping and the turbo will still create boost, but this will create a lot
of pre turbo pressure because the turbo will wastegate too little gasses trying to work hard for that boost target. That creates what we call back pressure and it steals power.
If the boost gauge deviates too much it might even be an exhaust leak also.

Aradin

Do you have a wideband installed?

TheShodan

iTrader: (14)

Explain your reasoning on how having one is relevant to the loss of boost pressure. (Just Curious).

Not to sound like an old ***, but I haven't run one is 18 years. That's for my tuner to utilize. Depending upon tuning, he may not be running that "rich" to show any additional symptoms. If the turbo is running lower than standard pressure, the fuel trims would be as though he's only at the reduced level of boost pressure anyway. AFR wouldn't be affected negatively.

Aradin

There is no specific reasoning. I'm just trying to get the whole picture here, like you. OP has yet to confirm or deny it's a boost leak issue. Until he does, I'm just analyzing what I'm reading here and thinking of other possible causes.

Txdragon

And the guage takes what part in tuning?! Lol! I'm not a pro tuner, but I believe your EMS needs to see what your engine is seeing to be any kind of useful, no?

I still believe something revolving around the dizzy/cam sensor ordeal anyhow..

TheShodan

iTrader: (14)

I gotcha. Just trying to understand your process of diagnosis better is all.

TheShodan

iTrader: (14)

The gauge sees the actual manifold pressure increase, The EMS is using a MAP sensor that hopefully is calibrated (and in the correct place) to similar manifold pressure. but that will be based upon a voltage reading. It's best if BOTH the MAP sensor and mechanical boost gauge come at least in close proximity of the same reading. But I'd never truly depend upon the MAP sensor to determine actual boost pressure. All it takes is the wrong selection box (i.e. 2.5BAR MAP vs. 3.0 BAR MAP ) to get an entirely different reading from what the sensor sees. With the Mechanical gauge, (Assuming it's at the correct source) you stay consistent to know what's really going on.

Txdragon

How incredibly odd. I'd trust the map signal before the guage. I get the premise of what you're saying. Just too many assumptions to be made. As far as tune goes, it's jacked anyways considering the EMS isn't seeing what the engine is getting, it's a tune from another engine, and admittedly the wrong dizzy. **shrug**

JRCivic1

The gauge doesn't really have anything to do with tuning... the purpose of inquiring about a gauge is that the OP stated that he was "seeing" 15 psi AND was using a stock MAP sensor at this time... and a stock "B" series MAP sensor will only read about 10 psi, so in effect, it is not possible to see 15 psi on his datalog.

OP, did you use the exact same parts in your Si as you are using now in the EF ??? Same engine, turbo manifold, turbo, charge piping, intercooler, fuel pump, fuel injectors ??? It is possible that simply tuning the vehicle will cure the issues that you describe, but the more specific information that you can provide here, the better chance we can offer a viable solution to help you diagnose and solve your issues if they exist - outside of the tune. Also, if you intend to run more than 10 psi of boost, I suggest you swap the stock MAP sensor with a bolt on type 4-BAR MAP sensor... you can bolt it on at the dyno three minutes before you tune.

LightningTeg

Sounds like a leak right at the compressor. It will make 15 lbs but not efficiently.

Car not being tuned is a problem also. You shouldn't be "gunning it" unless you know whats going on with ignition timing and AFR in the MAP

TheShodan

iTrader: (14)

Excellent observation. That simple premise almost bypassed me. And yes. More back-dated information is a must

K7-1Ktrevor

Txdragon

And that, sir, is the point I was trying to make for anyone inquiring about a possible tune related solution. Lol!

Much back and forth in regards to this issue with no update from the OP anyways.. **shrug**

TheShodan

iTrader: (14)

Pretty much.. . No details = no help..