zex_cool

can it be done ? if yes, how ?

problem is, when this douche wired my friends car he hooked up the IACV plug to the IAT and it burnt the ecu board beyond repair. i changed the IAT sensor since and switched the plugs around and it worked for a while, but if you drive it for a while the code 10 comes on. i need to fix this ASAP. it wont even last through the tune without the CEL coming on.

97sleepercivic

yeah it can be bypassed if u hit up ebay for those crappy chips that claim better gas mileage and more horsepower ( all of it is a load of grade a bull) most all of them are bypasing the IAT and make the engine believe that cold air is coming in and it needs to run richer.

But if u wanna fix your car instead of cutting corners its really simple and takes about five minutes, there should be three wires going to your IAT one will be ground, one should read five volts, and the last one should change anywhere from about 0.5v to 4.5v depending on the temp of the air.

zex_cool

IAT has only 2 wires. honda IAT sensors are useless anyways, so tuning around it is not a big deal....i just dont know what to do to get around it.

GhostAccord

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zex_cool &raquo;</TD></TR><TR><TD CLASS="quote">IAT has only 2 wires. honda IAT sensors are useless anyways, so tuning around it is not a big deal....i just dont know what to do to get around it. </TD></TR></TABLE>

I think you had better do some more research into how useful the IAT actually is in the Honda PGMFI system. I believe it's number 4 on the list of necessary sensors. So for you to say it's useless is telling me that your not sure how Honda's PGMFI system actually works. When you state that it's easy to tune around but you don't know how to do it...... wouldn't that mean that it's not all that easy?

I would suggest you have the ECU fixed or replaced if it as far gone as you say it is. Easy solution would be to have the douche that wired it incorrectly pay for the new ECU....That way your friends car will be able to be tuned properly.

zex_cool

honda iat sensor is useless "period"

reading of off intake manifold thats 130-140degress on a worm day is not useful....at all. when it gets cold richening up the ect temps is not hard.

running a different ecu would couse more problems. his harness doesnt have a VSS plug and switching to a po6 or w/e would send a cell for that too. he is running a p61 or something out of an obd1 cable tranny GSR

97sleepercivic

sry wasnt thinkin straight on that yeah theres only two wires and one should read a constant 5v (source/refrence voltage) the other wire should read anywhere from 0.5v to 4.5v (signal voltage) if both of those are correct at the sensor then the sensor is working properly its just not getting back to the pcm

GhostAccord

lol.... No matter how useless you think the IAT sensor is your not going to be able to tune properly without it. Personally I think your SOL without a properly functioning P61 ECU. If the ECU circuit for the IAT is burnt there is no way to trick or bypass it from outside the ECU. Only way I can think might work would be to find a Honda ROM editor that allows you to disable the IAT sensor. I'm pretty sure that neither Crome nor eCtune give you the ability to do disable the IAT. Maybe Hondata or Neptune do???? I've never used them so I'm not sure.

Good luck


Modified by GhostAccord at 11:48 PM 6/29/2008

zex_cool

yeah, crome is what he is using and i have ectune. neather are able to disable the IAT sensor.

looks like new harness and ecu are a must. [freak]!!

Relic1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zex_cool &raquo;</TD></TR><TR><TD CLASS="quote">yeah, crome is what he is using and i have ectune. neather are able to disable the IAT sensor.</TD></TR></TABLE>
there is a reason for that... even with off readings, the difference in requirements for 110* day is vastly different from a -20* day...
yes heatsoak sucks and tends to create slight tuning challenges, but running like it's one constant temp will cause even more problems.

also you need to read up more about ECT and IAT compensations, they are not directly related.

If you REALLY want to bypass it, you can do so with a simple resistor. Radio Shack sells potentiometers that you can change the resistance to what ever you want. (10k linear would work fine) connect to the center pin and one of the outer pins, doesn't matter which is which. Then datalog to see what the ECU thinks it is and set it where you want.

But please don't come back on here and complain that you torched your engine and are not sure why.
I did not suggest or recommend this mod in any way. (waits for the "my engine just died" thread)

zex_cool

not sure who you guys usually deal with, but i have all of mine IAT columns set to 0 and i havent had a problem EVER. my car is a stock block b16 pushing unknown amounts of boost at times and its still running.
this kids motor is just a very mild n/a build. im sure itll do fine. ill try that resistor "trick". and no, there wont be a thread about a blown up motor do to running no IAT sensor....lol.

GhostAccord

You will have to keep us posted on how well this external resistor works with a burnt out IAT circuit on the ECU.

Just wondering if this unsuspecting kid knows that his ECU is fried and that your on an online forum trying to find a hack to cover it up.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zex_cool &raquo;</TD></TR><TR><TD CLASS="quote">i have all of mine IAT columns set to 0 and i havent had a problem EVER. my car is a stock block b16 pushing unknown amounts of boost at times and its still running.</TD></TR></TABLE>

IAT columns set to 0 - is this a fair weather trailer queen your towing around?
Unknown amounts of boost on a stock block

zex_cool

you guys are funny. i think i like you. please keep going.

yes this KID is a very good friend of mine and he knows everything thats going on. as it wasnt be that [freak]ed his **** up in the first place. but i do love how some ppl turn simple questions into something huge.
i asked a simple question if it can be done or not. nothing more nothing less.


as far as my car goes, that thing has been raped more then i care to know. i got the motor with melted spark plugs from the original over when he ran a 50 or 75 shot of nitrous. it had two different turbo setups all tuned by me, a novice at best. and guess what, it still runs to this day and i drive the **** out of it everyday unless its way to hot outside....no a/c pawns me. oh and i got more timeslips this season alone then you probably have in your life.


btw, thanks Relic1.


Modified by zex_cool at 9:42 PM 6/30/2008

GhostAccord

Hey man If this external hack works great. It probably would have been easier to replace the burnt resistor inside the ECU. Because if the hack works that means the only thing that burnt was the outside of the resistor. But if the resistor is burnt/melted to the point that it has broken contact and or the trace is lifted. Then the external hack probably won't work anyway. The ECU could still be repairable if you know someone who can solder in a new resistor, lay in a new trace or add a shielded wire in place of the broken trace.

Good luck and keep those time slips com'n

97sleepercivic

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zex_cool &raquo;</TD></TR><TR><TD CLASS="quote">yeah, crome is what he is using and i have ectune. neather are able to disable the IAT sensor.

looks like new harness and ecu are a must. [freak]!! </TD></TR></TABLE>
i thought u had already replaced those, yeah from what it sounds like ghostaccord is right, u might get lucky and just have to replace a resistor in the ecu, if not yur sol on that ecu

locash

Not using the IAT sensor is pretty foolish, especially for a true street car. Just because you can make a not-so-impressive 320hp without one means nothing to me.

Ignore this clown and repair your ecu properly.

thumper64

What ecu are you running? I have like 3 virgin P28s and a virgin P2E I need to sell to fund the bodywork on my '94 Civic EX coupe. My brother wrecked the thing, so now I'm fixing it up and just don't have the money, so it's sitting in my garage, half finished.

zex_cool

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by locash &raquo;</TD></TR><TR><TD CLASS="quote">Not using the IAT sensor is pretty foolish, especially for a true street car. Just because you can make a not-so-impressive 320hp without one means nothing to me.

Ignore this clown and repair your ecu properly. </TD></TR></TABLE> go f-u-c-k you're self buddy.

Relic1

no need for harsh words man, this is a forum, opinions are rampid.

One thing I forgot to mention... swapping the IAT and IACV plugs will not blow the IAT portion of the ECU. It reads the resistance of the IAT, it will simply read the resistance of the IACV. (you sure it wasn't the EVAP purge, that's a more common swap)
This swap will blow up the driver for the IACV (or EVAP purge) which is different than the IAT issue you've been trying to bypass.

is the part in location Q31? that's the EVAP purge transistor.

zex_cool

i've been meaning to take a pic of the board but never got around to it, ill do it today for sure. if your right, and i think you are, why is still sending a code 10 ? this car is becoming a headache.

Rease3

im having this same problem i changed iat sensors with a new one from honda and the code still hasnt go away i tried to unplug the ecu and reset it and its still comes up with code 10. this is a mystery

jherry08

cel code how will i resolve?

Synodite

Heres my experience with that damned sensor. Stock '99 crv lx std, cel on constantly, bad power when warm, threw p0420. Tested both o2 sensors (both fine) kept throwing code. Hooked up obd2 dongle with app on phone to find IAT sending temp readings 28-45°f hotter than ambient temp under hood. Damn thing is mounted right off the intake casting and was soaking up heat from the block, this caused a lean burn condition, thus throwing the p0420. How to fix? Relocate IAT to the airbox like EVERY OTHER CAR EVER. Runs great now. No CEL.