s4 with s5 engine... ran fine untill i fixed the huge exhaust leak
 

i have an 87 with an 91 verts engine n tranny
im using the 87 ecu and wiring with 91 clips
had some kinks i worked out and drove it up and down the drive (couldnt go farther without brakes)
so i weld the exhaust up (which was cut open on the cat)
and then it would start and die imediatly

:scratch:

You sure the circuit from the fuel switch in the afm is making its way to the circuit opening relay?

Have you backprobed the ECU to see if the signal from the afm is reaching the ECU?

Did you disconnect the ground on the battery before welding?

Good point. Been down that road myself.

ah sounds like he fried something maybe? its funna to think people dont realize that that is electricity that makes welding happen. no magic

that or maybe ur tps is shit !!

do you have a vac gauge? if so, you can check to see if your cat is plugged. well, at least this is how you do it on piston motors. at idle it should be around 14", and open the throttle just enough to rev it up to maybe 2 or 3k, then watch the gauge. if it moves directly up and down with the throttle you're good. but if you rev it up and the gauge slowly goes way down, you're shit's plugged.

or just disconnect the cat if it's convenient and see if the problem goes away.

ok the exhaust was off when welded..
no i have not but im pretty sure its getting gas
i dont know how to backprobe anything, how do you do it?
and the tps is what came to mind when i thought about im using the 87 single sensor and the 91 comes with 2, if anyone has a wiring harness that goes from the rcu to that i woudl like to get it even if not needed....
is there any way i can hook up that dual tps to an 87 wiring harness/ecu?