DC2-ProdUcTiOnS

iTrader: (2)

Hey guys. So I have been putting 01-1058 back together and shes finally purring. It seems I'm dumping a tonnnnn too much fuel. Like fouling plugs in 5 minutes bad. Everything is stock and if not it is set to stock parameters. Im seriously confused on what could be the culprit for this problem, so I take to the boards for some brain picking of fellow ITR owners. Ok so follow along with me, I'll give you a breakdown of whats going on.


'96 Spec JDM ITR Motor.

(I have run this motor in 4 different cars. Each time has been with the stock JDM P73 ECU with NO PROBLEMS. No fuel, spark, vtec, oil problems at all. This motor is 95% stock, never been opened, nothing. In cars 3 and 4 I ran this motor with 310cc injectors, AEM Hi-flow rail, and have a FPR on the rail (set to stock 40psi pressure). Everything was PERFECT with this setup. Even tried to bring the car to Evans Tuning in PA to get a Hondata tune and he only made 3whp more than my setup with the stock JDM Ecu. We agreed not worth spending the $$ on Hondata and I went on my way)

- Chassis is '01 ITR running USDM wiring harness from the car
- I have usually run a AEM Intake, this setup has a CT Engineering Cold Air
- I have the same Fujitsibo Jasma headers on that have run this car since I got it
- Used to run a test pipe with Apexi WSII, this setup has a T1R test pipe and a 2.5" KTeller exhaust
- Swapped the oil pump from JDM to USDM to have proper CKF wiring and sensor. Changed timing belt in process. Timing was checked 3x and also by a Honda master tech and is correct.

Started the car the first round and was getting a MAP check engine light. Got a new one and still had a light.

Smoke tested the motor for any vacuum leaks. Had the tiny tiniest leak coming from the TPS sensor. Gave it a few turns on the screws, cleared the codes, started it back up, No more MAP CEL light. This light has been off since the change, and there were no other leaks shown from the smoke test.

Let the car run and she sounds lumpy. Sounds like it has a cam. Blip the throttle and it clears up and is nice and snappy. Roll on the throttle and it breaks up and rumbles up the rpms. Smack the pedal and she rev's clean all the way up to 6k. Back down to idle, and it gets lumpy again. Fuel pressure is stock rating of 40 psi. She's putting out some black smoke and you can smell it dumping too much gas. We pull the plugs and they are sooted black. And these are relatively new plugs. Like less than 200 miles new. They are COATED. wow. Dumping wayyy to much fuel. Fine. The 310's are too much for the USDM ECU. Its dumping more than it needs.

I go home, pull my STOCK USDM ITR injectors out of my PY 01-0590 to put in. No problem, only takes a few minutes. I do that and on my way back to 1058, I grab a new set of plugs since those were fouled and covered.

So now she is running STOCK injectors, stock USDM ITR ecu, stock fuel pressure, new plugs. Start her up and she idles a little better but still has a lump to it. Same symptoms. Breaks up when rolling on the throttle, but smacking it or blipping it shes super smooth, sounds great, revs right up no problem. No CEL's, nothing. After checking over a few things while she is running and taking her around the shop lot, you can hear it breaking up as it rolls through RPM's. Mat it, and she breaks up for a second then clears right up and wants to go. Get her back in the bay, and it seems to be slowly getting worse. Shut her down, pull the plugs. Again. SOOTED. BLACK. COATED. FOULED. dumping wayyy to much fuel still and you could smell it again towards the end of this 5-7 minutes it was running.


Now here's where Im at.

Could this ECU be messed up and be mapped improperly and is just dumping loads and loads of fuel?
Could that be the reason the previous owner spun a bearing? Dumping wayyy to much fuel and running to rich?? I couldnt smell the oil when removing the old motor. Previous owner had already dropped the pan to inspect.

I have a obd2b to obd2a jumper harness coming today so I can plug in the JDM ecu and since Ive ran this motor numerous times with that, hope that clears up the problem. But this still puts me in a bind of inspection. I know I can run a diff ECU for a day so I can pass, but if this is the case, WTF is up with the USDM ecu???

Other than that, Im at a loss as to what the reason could be for dumping this much fuel. If anyone has any ideas or things I can check over or look for, please let me know. IM SO CLOSE!!

Thanks guys.

94rs-turbo

iTrader: (6)

are you running correct o2 Sensor? primary and secondary?

DC2-ProdUcTiOnS

iTrader: (2)

There is a O2 sensor plugged into the Header that goes into the harness.

The T1R has a plug/wire in it but not sure if its actual o2 or one of those jumpers the fault the ECU to think its there. Didnt look at it that detailed before.

And again, NO CEL's for O2 or MAP or at all. No vacuum leaks either.

94rs-turbo

iTrader: (6)

you dont have the primary o2 spaced out or anything right? like o2 defouler

DC2-ProdUcTiOnS

iTrader: (2)

No sir.

F22Master

Have you checked your tps calibration?

DC2-ProdUcTiOnS

iTrader: (2)

I replaced the TPS when I had it in my last swapped car. It was running perfect when removed. Have I taken it off since then? No. The pedal and throttle response feels perfect. Its breaking up as it goes through the RPM's, not a throttle response jerking, its the motor spitting. NO CEL either for the super sensitive Honda TPS sensors.

CW-ITR

iTrader: (11)

I would like to jump my conclusion on the primary and secondary O2 sensors. Another word, back to the "basic" = Stock cat, stock O2 sensors and we will go from there.

DC2-ProdUcTiOnS

iTrader: (2)

My plan to check that as of now is to plug in the JDM ECU and since that doesnt look for the secondary O2 and i know my primary is there and operating correctly and see if that changes anything.

Also, this is the same o2 setup the previous owner was running and he didnt have any check lights or similar symptoms.

CW-ITR

iTrader: (11)

Sounds good. GL

Runnerdown

Was the throttle body swapped or fussed with? Sounds like the map sensor may not being seeing vacuum, or not enough of it. That will dump a lot of fuel. Try this simple test.

-remove map sensor, attach length of vacuum hose to it and connect to manifold vacuum. There should be two small ones on the plenum to choose from.
-Plug your finger over the map sensor hole and have someone start the car

car runs better? weak, or no vacuum on map sensor hole?

94eg!

iTrader: (2)

A leak in the exhaust manifold (upstream of the O2) can trick the O2 sensor into thinking it's seeing a lean condition. This will cause the ECU to dump a more fuel. Check for a leaky manifold gasket or a crack in the header. Usually this is a problem at light throttle where air gets drawn into the exhaust stream.

F22Master

Yeah, now that I think about it, this does sound a lot like a MAP sensor issue.

HondaPartsHero

Under the map sensor there is a small Oring, is that in place and not damaged?

DC2-ProdUcTiOnS

iTrader: (2)

Throttle body was not fussed with at all. Ill have to see if that works.

We did a smoke test to the motor and had no leaks.


Small O-ring was replaced with new unit, yes.




I put in the JDM ITR ecu and it was a little better at first but then went back to breaking up. But she's still rich.

DC2-ProdUcTiOnS

iTrader: (2)

So I put on the new MAP sensor.

Seemed to be running a bit cleaner but was idling at almost 2k RPMS and still had a check light.

Shut heR down and checked the codes. I got 3 & 14

MAP and IACV.

I know that MAP can throw either Code 3 or 5. What is the difference between the two? Too high voltage or too low voltage?? Or is it possible that either 1, the ECU was not reset from previous MAP sensor and CEL just hasnt gone away? Or 2, the IACV messing up the volume of air in the manifold also throwing the MAP as well?

I have another IACV im going to swap over. Clear out the ECU and try again. I only ran it for a minute with the new map, and it was idling high, but it sounded cleaner for the min it was running.

F22Master

Did you adjust the idle with the brass bleed screw on the top-front of the throttle body?

DC2-ProdUcTiOnS

iTrader: (2)

idle adjustment screw behind TB port has never been touched.

throttle stop screw UNDER the throttle cable plate has not been adjusted since 2 vehicles ago. All is tight and not affecting stop or position.

The only throttle adjustment I have made was tightening the throttle cable at the intake manifold bracket.

DC2-ProdUcTiOnS

iTrader: (2)

so it seems my MAP sensor was not getting any 5V power at all. I probed all of the lines and Im getting a reading from my signal wire but no reading on my power line.

Ran a tap line off the TPS 5v power since there weren't many other 5V lines i could find, everything was 12V. However, before probing I ran a 12V line into it and actually ended up frying my main relay. No more fuel pump power with ACC on at the main relay. All other lines get a 12V switch power, but switch 7 on the relay is not getting any reading which is the fuel pump. She cranks like wildfire, but you cant hear the relay click or the fuel pump prime. WHOOPS!

However I think this was the problem of me dumping too much fuel. No power at the MAP sensor is resulting in the ECU not reading any pressure in the manifold.

DC2-ProdUcTiOnS

iTrader: (2)

The MAP was the problem. Not getting a power reading. As for now I used a "resistor" ( i think thats what it is) to convert 12v power to constant 5v. I used the EVAP plug on the charcoal canister on the firewall to tap into for the in feed to the resistor, grounded it to chassis, and ran the output directly to the line coming out of the back of the MAP sensor plug.

j13

iTrader: (2)

I was going mention MAP. Another one would be a bad ECU. Old JDM ECU's go bad. I have a few. Plus I've noticed JDM ECU's seem to burn more fuel. Darker wet plugs, more stronger exhaust gasses, swapping to USDM made a world of difference. G/l

DC2-ProdUcTiOnS

iTrader: (2)

So in conclusion for this problem, it seems the wiring harness was a major part to blame for this problem. I was not getting any signal to the MAP sensor and also noticed some hacked up wiring through the alarm and other lines. This was causing all sorts of problems and had me chasing one light after another as it seemed the shorted signal kept jumping from sensor to sensor.

I ended up buying a whole new engine harness that wasn't hacked up and it fixed most of these issues. My chased signal from the hunting idle showed a IACV CEL however with the new harness it showed a TPS CEL. Swapped out new TPS and whala, good to go.

Just an FYI for anyone running a Walboro pump, I had to adjust down my fuel pressure to about 40psi from 45 to stop from running a little too rich and throwing a code. Seems to be good for now and once I get my inspection I will throw my JDM ECU back in and turn the Psi back up to 45 since thats what I was tuned at.

Garage_Spec

Looks like I need to retest my map wiring as well, my integra has an identical problem.