So last night I did a compression test on my 93 bubble with an 00 gsr. I disconnected the ecu and did the test and everything went well, after I changed the spark plugs, plugged everything back in, and now the engine doesn't even have a spark. What could I have done wrong? Is it possible to fry ur ecu like this or should I be looking elsewhere?

Thanks,
John

 

Make sure you connected the ecu back properly. Maybe connection is loose. Check the connections from the dizzy also.

 

Isn't there only one way to re connect the ecu? Its not possible to put the plugs in upside down is it? I checked the dizzy as well and everything looks fine, someone told me the coil may be messed but I'd think that's unlikely that it was mint before I touched everything and then after there's magically no spark. The cars wiring is kinda wierd though, I was checking fuses before all the other work started and for some reason there are 2 random cables getting jumped off 2 fuses but I didn't have the cover so I haven't been able to check what the fuses are for yet....any other ideas peeps?

 

is it cranking over? pull a plug wire and check for spark. Is the battery good? whats voltage of the battery? are the battery cables on correctly and tight? You'll need to post more info could be anything even a loss connection like was posted eariler.

I've never done a compression test myself, why would you need to disconnect the ecu? couldnt you have just unplugged the distrubutor cable?

 

I know, I disconnected main relay also when I did mine, just so fuel doesn't spit...
Ecu only goes one way, but I ment to say is to check if its plugged in all the way.
Did you change the spark plug wires? Maybe you got wrong ones and they don't reach the plug? Or plugs are faulted. Try putting old ones in just to see if it cranks.
Btw did you remove any other wires/negatives that you may have forgotten to re-connect.

 

you say you checked fuses but your missing the cover. did you check the under dash and under hood ones? get a test light and check them all. you may have popped your ecu fuse under the hood. Also check all your grounds

 

Ya, I pulled the plugs n checked for spark with the new ones first then when I saw nothing I switched back to the old ones and still nothing. I also pulled every fuse and checked them all n they all looked fine. The car has a gsr dash n I'm not gonna lie, the way its all set up seems kinda jerry rigged cuz there are random cables spliced in everywhere that don't look too professionally done. I also checked the battery terminals and they are tight n what not n the other grounds look fine as well. I dunno why I unplugged the ecu to tell u the truth either, a buddy just told me that's what I should do while compression testing it so I listened to his advice I'm gonna have another look at all the wires n plugs when I get home from wrk today cuz it started pouring on me last night n I was just panicking n not thinking straight lol should there be though in any circumstances wires bein plugged into any fuses in the interior box? I should prolly start off by figuring out where they all lead to n see if they are shorting anywhere...

 

possibly a reset button.... or just try taking the neg- terminal off the battery and connect it back.

 

Why did you disconnect the ECU? You could have just pulled out the fuse that controls the fuel injectors.

Something must not be connected properly, or the ECU is fried (which is highly unlikely).