ECU Tuning & Fuel Management - Morning Start Up

I know a lot of you guys have noticed this before in the morning or whenever your civics engine is at a complete cool. You start it up, put it in drive, and give it gas... but what is this? It is really zippy for the first 5-10 minutes! I have looked in the manual and it told me that the ECU does that to heat the engine up faster....Is there a way into tricking the ECU to think that the engine is cold all the time? Or will that really *uck up the car. Also if some of you could look at this: www.hondata.com . That link is to a company that apparently make chipsets for your ecu to give your civic more performance.

Cheers

Hondata makes good stuff. I've also noticed that when i start my car up in the morning, it idles really high (1500 - 2000 rpm) until the engine gets heated up.

I agree. I wonder if hondata does something like that? I find it hard to navigate around their website simply because I dont know what the hell they are talking about. I do know their purpose though

unplug the o2 sensor. it will set off a CEL and put it in open loop, like it is when its cold. but it kills VTEC (as it does when its cold) as well as killing the fuel economy. also, most of that power comes from the less heat in the engine bay, making lower intake temps.

So, if I removed the o2 censor it can ultimatley screw up the engine?

yeah, pretty much. its a bad idea. i used to be in your place, trying to find as many horses as i could for free. now ive found that the best ones are the ones you save up and pay for. it takes awhile, but in the long run its better. trust me, i dont have any extra money lying around, it takes a lot of work to build a car.

I noticed. What is the ratio... $10 per horse... that sounds right

yea, horse power isn't cheap these day, you know what they say. "Speed costs money, how fast do you wanna go?"

ORIGINAL: sacicons

yeah, pretty much. its a bad idea. i used to be in your place, trying to find as many horses as i could for free. now ive found that the best ones are the ones you save up and pay for. it takes awhile, but in the long run its better. trust me, i dont have any extra money lying around, it takes a lot of work to build a car.



so those rip off resistors that are sold on ebay actually are dangerous when they swear up and down it isnt?

yea thats sweet, i actually have a reason to wake up in the morning and go to school. lol

from what ive seen, its closer to about $50-$100/hp. but thats real, usable power, not advertised power.

Why does it cost so damn much? From what I have seen , most of it is a marketing gimic.

because ten or twenty real horses on the ground in a hundred horse civic, is a huge deal. most people think of the old school cars where an intake alone gives 20hp, but the 6 you get from a CAI make about the same difference in acceleration.

Hey, I have a question about all of this ECU stuff. I kinda figured that it was the ECU that was making the RPM's high until the engine warmed up, however, if I just let my car sit at an idle when it's cold, the engine RPM's change constantly between 1500 and 2000 RPM until the engine is warm and the "warm up" function on the ECU shuts off. I hear the engine just changing RPM and I see the RPM needle jumping around exactly 500 RPM difference. How can I fix this annoying problem? Do I have to get a new ECU or can I just have it reset? Thanks for the help!

try reseting it, then try checking the ignition timing. then try to see if you have a vacuum leak.

Alright thanks! I sure hope it isn't a leak of any sort, but I think the problem resides within the ECU because on some mornings it doesn't do this. However, I know that something else is going weird. Here are some of the issues I've had

1. A while back, I was coming out of my driveway when the engine started to bog down really bad, and I had barely let off the clutch. I had it at about 2K RPM and it just decided to die and not go anywhere. After that it took a while to start.

2. Today, I was about to leave and accidentally slipped it into third. I don't know how the hell that happened! But anyway, I started to take off and of course it stalled because of the high gearing. I fired it back up (after about 3 seconds longer than usual it starts) and took off out of my driveway. The engine started running VERY irratically up the street, RPM's jumping from 1500 to 3000! After some throttle feathering it stopped about half way up the street. Weird huh? Do you think that this could all relate back to the ECU? To me that sounds like a distributor problem but that's the only time it's ever done that... I'm confused

How would I check for a vaccuum leak or ignition timing? I'll try resetting the ECU tomorrow though Thanks for your help! lol I'm losing sleep over this!

you need a timing light for the ignition timing, and get a can of carb cleaner and spray it at the vacuum hoses while its running. if there is a leak, it will suck the cleaner in, and you will hear the engine bog down.

Alright thanks man! I reset my ECU about 10 minutes ago, I guess I'll see if it worked when I fire it up tomorrow. I'm sure hoping it will.

Okay, so I reset the ECU. It still does the whole jumping idle thing though. I noticed, however, that this might be linked to have something to do with the heater. Although the engine is pretty much all the way warmed up, (just before the ECU puts the engine at a regular idle) the heater is still blowing out cold air until the engine hits that low idle! I drove the car about another 100 feet and all of a sudden the ECU shut off its warm up high idle and hot air started to blast out of the vents... Weird huh? I tested this out this morning, just sitting in the driveway after the car was warmed up (drove it around a bit) I listened to the engine as I turned the heater on and off. The engine RPM's would actually adjust higher or lower to compensate for the heater levels? Same with the lights too a little bit! I really noticed though when the A/C was turned on. Now I realize that the A/C has to be powered by the engine with a pulley that engages and disengages when it is turned on or off, and on most cars I just notice the RPM's drop a little. On my car, the engine adjusts the RPM's higher to operate under the added load of the A/C.

I'm beginning to think that all of this RPM adjusting has something to do with the engine speeding up or slowing down for the heater/Air conditioner (I often use the A/C and heater to defog windows) but the engine is sensing it wrong, like it is on and off constantly when it's really actually on all the time. Could this be due to a dirty or bad ground? Any help with this would be greatly appreciated! I'll do one more test on it today when the engine cools down and I'll just leave everything off in the car and see if it still does it.

yayaaaaaa can you say 8 valveeeeeeeeee

the blower motor for the ac/heater requires quite a bit of power to run and it will make your engine rpms change. if you notice also your engine will change speed if you turn your headlights on. same thing

Actually it's just if you turn the AC on and off. The AC compressor is connected to the crank by a pulley, which steals horsepower, which is why many people remove their AC. I think the fans are just little electric fans.

ORIGINAL: sacicons

unplug the o2 sensor. it will set off a CEL and put it in open loop, like it is when its cold. but it kills VTEC (as it does when its cold) as well as killing the fuel economy. also, most of that power comes from the less heat in the engine bay, making lower intake temps.

Taking off the 02 sensor isn't thte most practical idea. I did it to one of our cars and we went from 19mpg to 6 mpg. It kills your gas mileage.