AE86 Starting Problem After Installing Brake Booster???

[hachidustin]

So I just replaced my brake booster, put all the stuff back together (under the hood and under the dash) and it wont fire up. It will try to crank, but not actually fire up and start. It was running fine before I swapped the brake booster. I looked under the dash again to see if I may have knocked something loose, but it all looks fine. Any idea's???

[ethergore2]

Did you install the plastic valve backwards by any chance?

[hachidustin]

Which plastic valve???

[hachidustin]

So it turns out I'm not getting spark. Vacuum lines are good, grounds are good, and the plastic one-way valve in the booster-to-manifold hose is installed correctly. So it must be a loose wire somewhere under the dash/hood. Got a friend coming over to look at it here soon.

[Jeonsah]

To check spark, I would start off by checking for spark starting at the spark plugs, then the spark plug wires, then from the dizzy, and then from the coil. Once you trace it back like this, you should know where its not coming from. If its not coming from the coil, you can then decide that it is either a bad coil or a wiring issue. Also, check all your fuses and grounds.

Good luck!

[hachidustin]

Okay, fixed the problem. It turns out, sometimes I was getting spark, and other times I was not. It was a grounding wire from my engine harness. I knew it was something simple eluding me haha! Thanks for all your guys help though, I appreciate the thoughts and idea's.