och
Member
- Messages
- 161
- Location
- Brooklyn, NY
Guy, I will try to make this one as short as possible, so bare with me.
If anyone remembers my old posts, you will know that I own a 1994 LS400 since 2006, and all this time it's been awfuly low on power. It takes off like a 3 cylinder Geo Metro, pings around 2500-3000rpms, and sounds trashy after that.
I've replaced everything that has to do with A/F - MAF, O2, ECT. Did full maintenance including plugs, ignition coils, distributor caps, rotors, wires, pcv, fuel filter. New timing belt and water pump as well. A bunch of other stuff as well - seafoam, clean throttle body, ran fuel injector cleaners - all to no avail.
I'm confident that my engine is in good shape mechanically. It run brilliant if I disconnect the MAF - much stronger pull and sounds healthy. I would run with MAF disconnected, however once in a while it would ping, after which the ECU will retard timing, and it starts performing eratic until I reset the ECU.
I havent replaced the ECU, but I did sent it for a repair service, which did nothing. I bought an Apexi Neo piggyback, but quite frankly thats a piece of junk.
So basically I'm confident my problem is A/F ratio, and since the ECU is the only part I havent replaced. I believe for some reason the ECU is leaning out the mixture (I will do the diagnostics described in this post in the near future - http://us.lexusownersclub.com/forums/index.php?showtopic=20851&mode=threaded)
But basically I've been quoted $900 for a new OEM ECU. I'm almost ready to buy it, but then if I'm going to spend that much, maybe I should opt for an aftermarket ECU? Can anything be had for not much more than that?
Now, let me say that I have no experience with aftermarket ECU's at all. I do have a friend whoever who programs GM ecus all the time, he's very talented and will help me. Of course I'm counting on this forum as well.
I've been reading this forum for a while now, and here's how I understand it. If I do get an aftermarket ECU, I will still retain the factory ECU. The factory ECU will control functions of interior - lights, seats, etc, which the aftermarket ECU will take over the ignition, transmission and fuel management. Is that so? Also, am I gonna have a bunch of errors on my cluster if the factory ecu is no longer controlling the drivetrain?
And now to the requirements. This new ECU that I'm looking for needs to be reasonably priced, as easy to install as possible, and provide decent capability. I dont have modding plans for this car, I'll be happy if it just ran as well as it should from factory. I'll be happy to just get my 250 factory prescribed horses, so make your recommendations based on that. And of course I'd like to get rid of the horrible Karman maf, so I'd like an ECU that will allow me to do that as well.
However, as an alternative, I need another recommendation. It is highly unlikely, but I might be stupid enough to decide and super charge this car sometime in the future. If anything its going to be a mild supercharge, wont rebuilt internals at all. Maybe 5 PSI and maybe upgraded injectors. So please recommend another ECU that can handle this screnario as well.
If anyone remembers my old posts, you will know that I own a 1994 LS400 since 2006, and all this time it's been awfuly low on power. It takes off like a 3 cylinder Geo Metro, pings around 2500-3000rpms, and sounds trashy after that.
I've replaced everything that has to do with A/F - MAF, O2, ECT. Did full maintenance including plugs, ignition coils, distributor caps, rotors, wires, pcv, fuel filter. New timing belt and water pump as well. A bunch of other stuff as well - seafoam, clean throttle body, ran fuel injector cleaners - all to no avail.
I'm confident that my engine is in good shape mechanically. It run brilliant if I disconnect the MAF - much stronger pull and sounds healthy. I would run with MAF disconnected, however once in a while it would ping, after which the ECU will retard timing, and it starts performing eratic until I reset the ECU.
I havent replaced the ECU, but I did sent it for a repair service, which did nothing. I bought an Apexi Neo piggyback, but quite frankly thats a piece of junk.
So basically I'm confident my problem is A/F ratio, and since the ECU is the only part I havent replaced. I believe for some reason the ECU is leaning out the mixture (I will do the diagnostics described in this post in the near future - http://us.lexusownersclub.com/forums/index.php?showtopic=20851&mode=threaded)
But basically I've been quoted $900 for a new OEM ECU. I'm almost ready to buy it, but then if I'm going to spend that much, maybe I should opt for an aftermarket ECU? Can anything be had for not much more than that?
Now, let me say that I have no experience with aftermarket ECU's at all. I do have a friend whoever who programs GM ecus all the time, he's very talented and will help me. Of course I'm counting on this forum as well.
I've been reading this forum for a while now, and here's how I understand it. If I do get an aftermarket ECU, I will still retain the factory ECU. The factory ECU will control functions of interior - lights, seats, etc, which the aftermarket ECU will take over the ignition, transmission and fuel management. Is that so? Also, am I gonna have a bunch of errors on my cluster if the factory ecu is no longer controlling the drivetrain?
And now to the requirements. This new ECU that I'm looking for needs to be reasonably priced, as easy to install as possible, and provide decent capability. I dont have modding plans for this car, I'll be happy if it just ran as well as it should from factory. I'll be happy to just get my 250 factory prescribed horses, so make your recommendations based on that. And of course I'd like to get rid of the horrible Karman maf, so I'd like an ECU that will allow me to do that as well.
However, as an alternative, I need another recommendation. It is highly unlikely, but I might be stupid enough to decide and super charge this car sometime in the future. If anything its going to be a mild supercharge, wont rebuilt internals at all. Maybe 5 PSI and maybe upgraded injectors. So please recommend another ECU that can handle this screnario as well.