Way Outta Control
Join Date: Sep 1999
Location: The Palouse
Thanked 3 Times in 3 Posts
Re: 1991 YJ starting (or lack thereof)
OK... so you've got spark. What's missing?
<ul type="square">[*]Timing[*]Fuel[*]Air[/list]Those are the three possibilities.
The fuel pump is turned on to pressurize the fuel line for 2 seconds by the ECM. Then it's turned off. From this point on, the CPS sensor must take over and send pulses to the ECM. The ECM sees the pulses and then turns on the ignition and the fuel pump. The ECM is turning on the systems, and you've got spark, but likely no fuel pump, or the injectors aren't pulsing. So, we're trying to figure out if the problem is in the fuel delivery.. where is the problem.
Dumping fuel in the throttle body throat may/may not help. Raw fuel can sometimes be drawn in and flood the engine. It's not atomized into a vapor, that's the job of a carb, or the fuel injectors. That's why I'd still suggest the starting fluid. It's already a vapor, not like the fuel you dump in.
So, if the engine doesn't start on the starting fluid, you can then bet the problem is timing. Have you checked the static timing?