I was just wondering if there is an accurate way to find out if the ECU, main computer, is good or not. I was told to take a voltage reading from a sensor, such as the tps, which I did, and it read 5v.
thanks
-Aaron-

 

5 volt sounds good, but if the logic is screwed up (some fault), then theres soemthings you can get at a autoparts store that will tell you whether your outputs are right!

 

Hey, I need to know about the computer though, if it is still good or not, what are some ways?

 

the equipment checks the output of the computer, but you can check with a logic board and it will tell you whether the computer is good, or whether it just needs to be reprogrammed.

 

Plug a known good ECU into your harness and see if the problems repeat. There isn't an easy way to test an ECU without a test bench and a good grasp of what you need for for signals. The 5V test is stupid, there are tons of things that can happen that won't show themselves with that test.. One of your signal inputs can be bad and the ECU still puts out 5v, I don't know who told you to do that..

 

I read it on some site to do that so I dunno how legit it is. What about if I take apart the ECU? What should I try to look for? Also my engine wont start the engine is good, I replaced the fuel filter, and also did a spart test, and found out that cyl. #4 has no spark, not sure if it is from the plug cable or the actual spark plug. What else should I be checking for? The timing is good, when I try to start it, the engine turns over and kinda shutters a little, and then tries to turn over faster. The ecu does not flash, so i am not sure if it is still good or not, because it should be telling me there is a problem i would think. There is no CEL so I am not sure what to check, I checked both of my fuse boxes a while ago and there are no bad fuses. Anyone have any ideas?
-Aaron-

 

lol, similar problem, i need a way to test if it is completly dead, someone explain the 5v test.

 

Seriously, borrow a good ECU from someone and try that first. if you're doing a swap, it's more likely you have a wiring problem, so try to eliminate that first by using a known-good ECU. If you have no spark on #4, start checking from the plug back. Get a multimeter and do a continuity check on the plug wire, and go from there. Chances are it's something simple. If you're not sure if it's the plug wire, they're probably old enough to need replacing anyway.. I'm not telling you to take the shotgun approach to testing, I'm just saying there are many more things that it could be besides the ECU, and because the ECU is the hardest to test, do that last.

Better yet, try your ECU in someone else's car and see if their car runs like shit.. you have to establish some reference point to start from...