kevinmcgee

hey i have a 94 integra rs turbocharged. i have an electrical problem with sensors probably well before it was turbo'd. its getting weird readings and flucuations from the ect sensor, tps sensor, iat sensor, possibly o2 sensor, engine load sensor, fuel injectors, and the iac valve has a faint high pitch buzzing noise. i've replaced all the sensors and no difference. also my distributor gets hot and chews threw distributor caps every 2 months and have to clean them every couple weeks. the spark plug wires get hot too. i've replaced distributor aswell no difference. i have an aem ems so when i plug my labtop into it i can see the sensors fluctuating even when the engine isn't running. i've replaces wire harness on the engine, checked all the grounds on the engine which are all fine. seems to have a grounding issue but can't find where. tried different computers, switched main pgmfi relay no difference. all these sensors seem to be on the same circuit acording to the wire diagrams. i did notice that the plug going into the iac valve had been melted at one time. i've tried unpluging each sensor one at a time and still no difference. does anyone know where and how to fix my possessed car? thanks

hondarules7

Pull the motor, strip the harness out and install a new or known good harness, and it should fix your issues.

kreatekustomz

I'm a little lost here... You said you "replaced" the engine harness, however; you said the plug on the IACV looks melted?

If thats the case its not the sensors or the engine harness. You may have already damaged the engine harness again if its gotten hot enough to melt the plugs. So you need to pull not only the engine harness, but the injector harness, as well as strip the main harness and look for damage.

Ground could be the problem but all those sensors are not running off the same ground... I think you have an ECU problem. might want to ask AEM if you can take the cover off and look for damage?

kevinmcgee

yes i replaced the wire harness on the engine which unplugs at the left and right side by the firewall. the old harness had the one melted plug and a few other sensor plugs had slight fraying of the wires where they go into the plug. the new harness did help a bit but didn't solve my problem. with the old ecu, i can't plug in my labtop to see how all the sensors are working but still have the same noise from the iacv. so im thinking its not an ecu problem. i took my car to an electronics speciality shop that had it for 4 days and couldn't figure it out. they did say there is definatly a problem seems how the engine is off and your sensors are bouncing around that much, most likely a grounding issue, just not sure where. when the engine is running the sensors are still not normal. only way to tell if the aem ems is ok is to try on someone elses car same as mine which i haven't found yet. so in the mean time i'm going threw all the wires threwout the whole car trying to find where its coming from.

kreatekustomz

If the IACV is clicking with the car off you dont have just a ground problem...

When did this problem occur? anything weired, or out of the ordinary happen right before these symptons took place?

I know the ECT is on the same circuit as the AC, if the diode is bad then you will see problems, The IACV is on its own circuit utilizing the Injector harness routing via signal.

Again if you are having this problem with the car off your sensors are recieving a signal.... if the problem is so presistant, as in the IACV just clicks clicks clicks then you should see if theres a problem in the main harness (assuming you bought a BRAND NEW engine harness).

again I see it being an ECU

kevinmcgee

this problem probably occured a few years ago but driving wise you wouldn't really notice other than a hickup/missfire the odd time and constantly cleaning the distributor caps because it keeps corroding the terminals. the AC was removed aswell. the IACV and injectors do run on the same circuit, a yellow/black wire. the ECT, IAC, TPS, and o2 run on same circuit aswell. when the car was on the dyno looking at the ECT signal it should be pretty steady like around 170-180 degrees, one the engine was running it bounces a bit but when it was under load it was between 150-250 degrees like way off the chart. the gauge itself was fine, half way. the iacv just clicks once when you turn the key on. i thought maybe there is a voltage regulator gone bad but thats in the altinator which was replaced aswell. i do need to try my ecu on another car to make sure that its not that.

kreatekustomz

The ECT, IAC, TPS, O2 have the same GROUND... They done run on the same curcuit. The ground is located on the back of the block on B18a and on t-stat housing on the rest.

Are you boosted? if so what turbo you running?

kevinmcgee

i checked that ground on the t-stat housing and all the others on the engine which have full continuity.
it is boosted now, running at 15psi it made 275hp and 260lbs torque. it wouldn't take anymore boost because it started pinging which would require race fuel but it might be possible my distributor issues and electrical issues might be holding it back. i used to have a turbonetics turbo on it but sent it back and got this masterpower turbo, possibly a german company or somthing but it works good.

kreatekustomz

Well checking continuity on your grounds wont cut it. You need to check the resistance using a meter...

You should strip the harness and see if theres a problem there. like i said the sensors arent running on the "same curcuit" but rather run off the same ground.

The ECT "fan switch sensor" runs off the same curcuit as the AC...

If you have truelly replaced all sensors with new sensors, replace the engine harness, then you need to check the main harness.

Keep it simple and try the ecu in another car first.

my1stteg

im kinda having the same problem first i replaced my main harness and main relay and my car started but when i turned on my head lights my car shut off only my lights would do this and it would only start if i take out my power window relay ive also replaced my under dash fuse box after trying to locate the problem and turning the lights off and on when i would do somthing new now it dont start the relays working but no power to lights winsheild wipers brake lights or windows but what created the problem was whe i put in the new harness i had it running the i pluged in my heater and the car turned off right away as if a fuse blew but their are no blown fuses i am in need of some help bad ive replace 3 harness 2 fuse boxes and a ton load of relays ive visualy checked the grounds on the engine i dont know how to really check them and another thing i put a multi meter on my intake manifould and it shows 12.3 volts when the key is in the on possistion please help me ive run out if ideas of what it could be or what to do oh and its a 1990 integra gs with a 1991 ls doch non vtec

kreatekustomz

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Well welcome to the gang. I started by helping the OP find his problem but now I'm in the EXACT same boat as you "my1stteg" The odd thing is I just figured out after tracing down the short that the problem is coming from the power window relay. I haven’t gotten the chance to look any further into the problem but we have the exact same issue.

What harness have you replaced?

I've found that when the Power winder relay is plugged in I see continuity to ground in my complete fuse box, as well as through my ignition switch, strait to my battery, from my battery I'm causing a ton of resistance in my grounds. The resistance in my ground contacts is ultimately the problem in the car not running properly (same for you)

did you perform any modifications before this problem occurred?

my1stteg

i just got done checking my grounds under the hood and they are all good i check the ground to the ecu too and thats good as well and the harness that i changed was the main harness that gos from the headlights to both fuse boxs and the ecu and everything inside the car im at a dead end right now its weird that my headlight wsitch seams to make my relays click with out the key in the on possition or in at all (thats with the porer window relay in) i have no idea what to do now i dont want to have to change the harness again

kreatekustomz

well your headlights will work without the key in the ignition. What relay is clicking?