94lsboost

Car: 94 integra RS
Motor: B18c1 (stock head, stock sleeves, cp pistons, eagle rods)
Turbo/fuel/tuning: T3/T4 .60 (16 psi), walboro 255 w/ rc 550's, hondata 200 p28

Background: I had the car tuned a few months ago, after driving it for a while I decided I wanted to up the boost. I headed back to the tuner and we upped the boost to 16 psi (stopped b/c injectors were getting up in their duty cycles) and it made 325/217 on a mustang dyno.

After the dyno session the car idled perfectly and ran very nice. About two days later the car would start to stumble and load up on fuel. Sometimes when you started it, it would idle perfectly, sometimes it would die instantly. On those times when it would die, when I gave it gas to try to get it to idle it would fight me abd try to bog down. IF I would hold it at 3k rpms, it would bring itself down to 2000, or 1500 and then shoot back up, then back down...etc every 2 seconds or so. Then as I said, sometimes when you started it up, it'd be fine... or if was running shitty and you drove it, sometimes it would do ok...but then right back to ****.

Anyway, long story short it finally threw a CEL. I checked it and it was 7 - tps. I got a TPS sensor, and when I went to change it I noticed the electrical tape around the splices (where the builder spliced in the extra TPS plug to reach from where the stock one is ran with the MAP sensor plug which is now on the GM 3 bar on the firewall) was coming loose from heat. I started unwrapping it and the red wire (middle of the plug) that goes from .5ish volts to 4.5ish volts when you cycle the throttle just fell apart at the splice. I put it back together, and started the car and it idled fine, but the CEL was still on. I checked the CEL now and it was # 1 - o2 sensor. I drove down the road and it drove great, so I assumed since the cel was off and the car ran great (A/F was back to perfect after being way rich before) that the bad connection on the TPS wire was the problem. I also assumed that the o2 sensor was fucked b/c of the car running pig rich (pegging the A/F gauge at 8.0 under boost). I pulled the o2 out and cleaned it, but it still threw a code and idled shitty.

I just figured that the o2 was bad and I went ahead and ordered one. I drove the car for a day and a half, and it idled sometimes, sometimes it didnt (i blamed it on the o2 and figured it'd clear up when I got my new one in). After about a day and a half, I started the car and it was back to jumping all over the place. It wouldn't idle, it'd fight me as I described above. I took it down the road and it was just like before (it will stumble on it's face, if you get into it after about 3 or 4 seconds it will hit boost cut sometimes). Exactly like before, only this time it's not throwing a code for the TPS. I have no idea what's wrong, and I'm lost.

I hope I didn't leave out any impt details, if anyone has any ideas please let me know. I'm waiting on my o2 sensor, but I know that's not the main problem... so please help if possible?

Flamenco-T

This may sound stupid but it sounded like ignition jumping all over the place. Try to check the ignitor ground (on top of the t-stat housing) I have had that issue with a customer's car similar to yours and after going thru all the troubleshooting, it turns out the ignitor ground was loose. We tightened it back up and it was good ever since.

stan

94lsboost

Will do, I thought ignition too...but for the most part it's breaking up on the bottom end, and not the top end where ignition generally does. However I guess if it was a ground it could be doing it wherever. So thanks for that, I'll check it as soon as I get back to the car.

94lsboost

the ground is fine, anything else?

94lsboost

anyone?

94lsboost

help?

94lsboost

?

bubbahatch92

Try changing your spark plugs. They are probably fowled out by now if your running that rich. What you think is boost cut may be a heavy misfire. I would change your plugs and carefully inspect the rest of your distributor components for any defects (especially the cap and rotor). I'm not sure about your set up, but if your car was tuned then in most cases the o2 sensor should not be doing anything under boost. You said your builder spliced wires for the tps and I would assume for the map sensor also, so I would look at those connections agian just to make sure there is nothing else wrong in that area.

Do these things i've posted and let me know how it turns out. Good luck

Darkness

94lsboost

I changed the plugs, I pulled the cap off and inspected everything.... all is fine. I checked the wiring for the external coil (msd blaster ss), and also rechecked the connections for the TPS and map sensors...

I'm sure the o2 sensor isn't doing much, other than maybe affecting idle a bit. The major symptom I can see is that the car is pretty rich, even at idle when it's screwing up. When it's not, the a/f is fine. So it pretty much has to be a spark issue, doesn't it? I guess TPS could also do that...

PyroProblem

Since youre running extremely rich, it sounds like maybe your ecu is receiving a bad sensor input. Possibly your MAP sensor is giving a bad signal?
How is your fuel pressure? Maybe you have a vacuum leak from the extra boost at a gasket and the O2 sensor is seeing a lean condition and richening it up?

94lsboost

How do you test the map sensor signal? I unplugged it and the car died, I'm assuming that is correct?

94lsboost

I tried a different map sensor, and a different external coil and still no luck....

PyroProblem

How about fuel pressure?
Maybe the extra boost ruptured the diaphram inside the regulator causing it to run high pressures?

All the plugs were black so I dont think it would be an injector issue, unlikely that all of them would act up at the same time...

Still throwing the o2 sensor code only right?

PyroProblem

You might want to get your tuner or someone else to datalog some of the sensors while your driving the car.
That way when it starts to act up, you can spot which sensor is malfunctioning and giving bad signals to the ecu...If all the sensor signals are correct and everything checks out, its gotta be something mechanical like the FPR or a vacuum leak or something like that...

94lsboost

The fuel pressure will be the next thing I check, however my gauge (on the rail) quit working a while back so i gotta get one. I'll do that tomorrow and keep you posted...

and yes, still only the o2 code

agrn93ls

Dude go ahead and rewire your map just to be safe, map sensor makes a huge difference on driveability and if your hitting boost cut b4 you are supposed to then it may be map related since that is what determines boost cut is info from the map, then you can take a meter (volt meter ) and hook the ground wire to a ground and take the red from your meter and check and make sure you have a 5 volt signal to the map a ground and a reading out of the map sensor 0-5 volts. turn ignition on (key on, ignition switch) and check voltage and then start and run engine/ or hook up a vacuum gauge to the map sensor while the ignition is on so youll have voltage then pump up the vacuuum to 20 in/HG. and see if the voltage goes to the other side i forget but off vacuum is one end of the 0-5 volt scale and vacuum around 20 in/HG is the other end of the 0-5 volt scale. had a car come in the shop the other day with a bad map sensor and if it ran like complete **** that would be an improvement, map sensor made unbelievable difference

remember on speed density cars (hondas, and cars that dont use MAF-mass air flow valve) the map sensor is all you have for fuel control except you 02 sensor which is really only fine tuning what your map sensor is telliing the computer. you can check your 02 sensor by hooking a volt meter to your 02 sensor, hook your black wire to ground and the red wire to 02 sensor (search for the right wire to hook to) one of them should swing for .0 to .9 volts or roughly .1-.8 somewhere in that range but it should have a constant swing up and down

BUT if your map sensor is bad it will **** up what the 02 sensor is doing so you could have a false 02 code and it be the MAP ******* up the fuel control and the 02 cant perform. basically.

you obviously know how to check your TPS check it again b4 the tps wires are cut, not on the tps side of the cut but the other to make sure you are getting good connection at the cut. also do the same at the MAP

94lsboost

I tried a different map sensor, with no luck...today I'm gonna look over the wiring and see what goes there.

I'm also gonna test to see if it is the fuel pressure regulator today... i'll keep you posted

94lsboost

I tried a different fuel pressure regulator tonight, no help. I also checked the wiring on the map sensor and it was correct. I have a different TPS to swap in and , so I guess I'll do that tomorrow even though it's not throwina TPS code anymore after I fixed the wire. Anyone else have ideas??

When I hit boost, sometimes it goes to about 8-9 and sometimes it goes to about 11 (a/f)....it was tuned pretty close to 12.1.... so either way it's rich, but half the time it does one, half the time it does the other...wtf?

agrn93ls

hey check your plugs, see if one is real black, it almost sounds like maybe you have a intermittent sticking injector, get ahold of a stethescope if you can and while the car is running listen to the injectors and make sure they are all clicking, and sound equal to one another or close, real close. if you cant get a stethescope, they sell them at Oreilley's i think, use a long screwdriver or prybar and put the metal end on the metal part of the injector and put the butt, plastic end of the prybar/screwdriver directly to your ear, put your ear on the end flat and you can hear the injector's through the bar. especially try this when the car is acting up if you can to see if one is not clicking. if you have a fuel pressure tester or gauge you could also see this when you turn the car off and pinch off both the fuel in and fuel return lines and see if the pressure drops.

94lsboost

Thanks, I'll check that... it seems like it is idling shitty (rich), but generally runs good in boost (still a bit rich), then every 4th or 5th time I drive it, it will take a spell where it just gets ******* retarded. it'll sputter down to like 1500 rpms and I can stomp it to the floor and it'll just stay there, maybe jump to 4k then back down... and finally sometimes after 10 or 15 mins, it'll come out of it.

agrn93ls

Ok, also check ALL of your connections especially anything fuel or ignition related, if you have a tester distributor or coil you may try that, unplug and replug in all your underhood connections, like the distributor main harness connections etc... you might even go the the ECU/PCM and unplug and plug it in as long as it wont disturb your eng management, check any hacks there also

too bad im not still in Ky. maybe i could be more help, i was born in Owensboro

PyroProblem

Does your Hondata have datalogging?
That would be a great diagnostic tool to see if its your sensor(s) or something mechanical.

So basicly its running rich, idles funny, and intermittently changes A/F ratios in boost...

This kinda sounds like it may be a temp sensor...ECT? IAT?
Try unplugging each one seperately and see if it runs better. See if the "default" value runs better than the "actual" value. Be sure to clear codes in between sensor tests.
Got an ohmeter?
Being that it happened right AFTER you turned up the boost, makes me think you have a vacuum leak, but an intermittent one?

How is your brake booster/check valve functioning?
Hope you get this thing fixed!

94lsboost

I changed the o2 sensor and got the o2 CEL to go off, no cel as of now. I'm sure after running rich for a week or two it'll **** up this o2 as well though. I listened to the injectors with a stethoscope and one of them sounded louder and maybe a bit slower....not sure what the margin for error is there though. I tested my resistor box and the resistance on all of the injectors and 3 of them were 4.1 ohms and one was 3.9 ohms.

I have a friend who's gonna test the injector's flow on a lab scope computer on tuesday, so that should rule out injectors. I'm gonna check the remaning sensors that I haven't checked yet... what is the ect?

agrn93ls - That's cool, ownesboro is a pretty nice place, there's actually **** to do nearby, unlike where I live. I'm pretty much an hour from any type of real civilization.

PyroProblem

ECT- engine coolant tempature sensor. If its faulty, it could cause your car to run in open loop (rich) thinking the car has never fully warmed up yet...

Are all your plugs fouled out? or just 1 of them?

Sometimes certain type of fault codes need more than one trip or drive cycle to set the CEL....

94lsboost

I'll have to check the plugs again, at first it seemed like it was mainly #1...then I checked them a bit later (while the tps was still malfunctioning b/c of a wire broken) and they were all rich.

I unplugged the sensor in the #3 runner of the I/M and it didn't do anything, the car idled/ran the same... then I plugged it back in and unhooked the sensor on the back psg side of the I/M (which I assume is the ect?) and it idled down and got a little worse.