Basic info...93 Si, OBD1 JDM GSR swap. Ran perfect since I did the swap a few months ago with no issues whatsoever.

Sooo...driving to work Thursday morning, out of nowhere I lost power and poof...limp mode. Searched and everyone keeps saying to just reset the ECU. I've done it both ways several times(pulling ECU fuses etc, and pulling the battery terminal). Even tried a different ECU...does the same exact thing. It will rev to about 3k...then dies until it reaches idle again.

Anyone have any idea's what could be causing it to be stuck in limp mode...even on another ECU? Thanks in advance.

 

First do you have any codes? Sounds like your map sensor could have took a dump on you. Also do you have any vacuum leaks, you can check for that with a can of brake parts cleaner.

 

I don't know too much but I'd imagine a very important sensor isn't getting the message to the ECU for what ever reason whether it be it failed or a short to ground but since it's happening in different ECUs, that would say it's everything but the ECU.

 

The only code I was throwing before this happened was a bad o2. But it's been throwing that code for a few months now with no problems. Not throwing any other codes at all. I'll replace the map sensor tomorrow and see if that works out though.

 

How about you go TEST IT before you start throwing parts at your car! Sheesh! Test everything you can with the necessary equipment and getting a multimeter is a great way to test 90% of potential problems on this or most any car with an electrical system.

 

Because it only took me 45 seconds to swap out the Map...instead of going out any buying a multimeter just to test it. It wasn't throwing a code for the Map either.

Moving on...the new Map didn't work...put the old map back in. But my fuel pump relay is being tempermental, so tomorrow when I get time I'm going to swap that out for a new one as well, reset the ECU again and see where I stand.

 

Any person who wants to be able to diagnose electrical problems on their car should own a multimeter.. You can pickup a fairly decent one at radio shack for like $20 and it'll accomplish 99% of your needs. Buying a multimeter is cheaper than throwing parts at a car. As for the multimeter, you can either get a digital or analog, I got the analog because I figured an analog would be more accurate since it's cheaper to make an analog than a digital one, but what do I know; it also taught me how to read an analog meter, something I'd never really done before.

 

I have no problem getting/using one...I just don't currently have one. But I do currently have an almost endless supply of spare parts, so swapping out stuff is no big deal to me.

 

Why do you have so many spare parts but no multimeter??? If you have the part right there, be my guest and test it out but a multimeter is the true way to see if the part is bad b/c you could swap in one part for another and they easily could both be bad.

 

i just had the same problem on a car turned out to be that the washers on the fuel line supply were the wrong ones so i went out to a yard loosened and took both washers after that no problem no the owner is happy
its caused because the pulsation damper assy. is not sending the correct amount of fuel so check the washes on the fuel line and fuel rail

 

I have so many parts because I have a few extra motors and extra parts from other motors still laying around. I know the extra parts aren't bad because they are all on/or came off of perfectly running motors. Everything that was bad, or had problems with, I throw out immediatly just so that never happens.

I've been driving the car since May without any issues...it just did this out of nowhere's. My FPR reads the same 40psi with the key on and 35psi with the engine running that it did the day I dropped the motor in.

I just noticed today that when the car is cold, it doesn't have this issue. I replaced the main relay that was hicup'ing yesterday, started it...rev'd perfectly...so I thought it was fixed. Let the car warm up...poof...same problem, won't rev past 3k again. Calling up a friend today to bring his multimeter over to see what he can come up with.

 

i know what it is

 

No you don't. But I solved the problem a day or two after my last post and have been driving it since. Now go away troll before you get reported.

 

At the very least, you could've updated us on the result of what was needed to fix the issue...

 

I was having issues with my laptop at the same time, I even made a thread about that also. So I wasn't able to get on Honda-tech everyday. It ended up being the TPS even thought the TPS was tested good and didn't throw a code. Everything is A-OK now.

 

So from the outside, the TPS (throttle position sensor which is on the manifold) looked fine but when you tested it with a multimeter, it wasn't within spec/was bad? Or was it sticky where while it was within range, it didn't vary its output, kinda like a bad O2 sensor?

 

It's on the TB. Never put a multimeter to it. I figured I'd go through the process of elimination. Since it wasn't the map, next I tried the TPS. Unplugged it and the problem went away. Swapped it out for a new Blox TPS off my ITR motor and poof. Problem solved.

 

Oh, ok, well thanks for updating the thread for us!

 

It sounds like that TPS had something wrong with it that would have required a lab scope to diagnose. TPS 'dropout' can't be tested with a multimeter too easily.

 

Analog multimeter? He said he didn't test it with a multimeter though...