As mentioned, log your fuel trims at idle. My bet is that they are close to if not at one of the extremes of adjustment.

While the engine warms up, it is in open-loop and doesn't have the adjustment of the fuel trims to get it at a nice stoich burn. The fuel trims only come into play at closed loop. Once you get warmed up, your fuel trims help you out and get you just enough adjustment to idle correctly, but since the trims are so far off, while warming up under open loop, yout don't get that adjustment (only table lookups) and you are either very lean (most likely) or very rich.

My bet would be that your idle fuel trim is very positive , ie +10% or more.

Check it out and let us know.


Eric

 

During closed loop operation the car LTFT's ans STFT's are within 1%, however because of the agressive nature of my cam's

.462 intake (11.7mm) .457 (11.6) exhaust, 224 actual duration 265 advertised

the idle was Abusive at best, but with the open loop adjustments it just purrs like al ittle kitten. even in open loop when i set the target af to 14.7 it idled like it did in clopsed loop but at 13.4 it's perfect.

 

sorta off topic, but has anyone made a sort of "vallet map" yet? Where you set the rev limiter at like 2500 and stationary rev limiter at like 1500? I think that would be a cool idea so you dont get some ******* vallet parker trying to floor it around with your car. I know people that vallet cars and they floor the **** out of them sometimes.

 

I just received my cable today. The first thing I wanted to do is to backup my OEM ROM. However, I can't get it to "READ from ECU".

I could open a ROM file and then do a "Compare to ECU". Here is a screen shot. But for some odd read I just can't backup the ROM file. I have a '03 with a P0300 code fix flashed by the dealer. And I am running ECUFlash v1.27 with updated XML def.

 

Link to thread that contains some info.

 

and this is exactly what I get when trying to "Read from ECU". And yes, the ignition was on, and the cables were plugged in before I ran the ECUFlash software. And I don;t want to start anything until I can get a backup of the original ROM file. Any idea?

 

Thanks for the info, but the problem is that I could not even read the ROM file off from the ECU. I have a screenshot above.

Just to test if the cable is in working order, I tried to do a "Compare to ECU" and it seems to be working correctly. So I am confused now.

 

It may or may not be relevant that Shiv has emphasized that he could not reflash an ECU that was reflashed by a dealer pursuant to resolving a P0300 code issue. If someone can confirm one way or another that this IS or IS NOT a problem with this device, that would be useful.

 

That's exactly what I am thinking too. The funny thing is that I could even successfully "Test Write to ECU". I don't want to actually write anything to the ECU yet until someone confirm that I can simply update my ECU with any OEM ROM and start modifying the parameters afterward.

 

Do you receive the error mentioned in this post? That's my current problem. I can empathize with your pain in having the cable and the software and not being able to tweak anything.

 

Nope! I can't even download the map from my ECU. It just stuck on the screenshot that I posted above.

In your case, you just have to send your ROM to the "experts" and have them look into mapping the defs.... and wait.

I am wonder if it is possible to flash it with other OEM ROM so you don;t have to wait for the new defs for your ECU. Not sure...

 

Ok my STFT is around (-3,3) but my LTFT at idle and Light throttle is (-12) would that explain it? sounds like im a bit too lean on what you guys reffered as TIP-in with the 880's

 

I wanted to answer here instead of the PM's..

I have seen a P0300fix ECU rom, therefore it has been extracted before.. Its possible the ECU is being "Quirky" but the flash and read mode are both boostrap functions, and should not care what version of that rom your running..

You really need to use your cable to extract a rom on another Car/ECU to be 100% certain its unique to your ECU and not your Computer..

You probably can flash your ECU with a different Rom, however you do need to get your immobilizer code off the ECU to get the car running with a new flash rom.

If you can sucessfully extract from another car, and not yours, see if you have anything installed on your car that can affect/confuse the cable, a good example is the ECU+ with OBD-II jumper enabled, you cannot reflash without bypassing the OBD-II function in the ECU+, Some piggybacks may add components in-line to your ECU harness that might also interfere with it, so if you do have anything like that, you might want to remove it.

The cable relies on a trigger voltage thats switched on, so anything that affects that could affect its ability to correctly operate.

I hope this gives you a starting point to troubleshoot from.

 

I only have UTEC hooked up to the stock ECU. I know some people have UTEC installed and still have no problem extracting ROM file from the ECU, but I agree that I should I should start eliminating any possible causes. I will take off my UTEC and and try to download the ROM file again tomorrow.

Thanks!

 

I do also have a UTEC, and had no problems extracting my ECU, but everything is different so it can't hurt to start with removing it.. But before you go crazy, try extracting an ECU on a different Evo (if you can, and know someone nearby) so you can be sure its unique to your car.