fuel injector pulse signal
got a '91 tuned port.had sat for 7 years.replaced the fuel pump and filter,ign.module and ecm.cranks and dies.fuel pressure and spark are fine but injector pulse fades away.checked all ecm power and grounds.sent to dealer,they are lost and just running up my bill.injector maintains 12vdc at all times key is on.tried a third ecm for gp but to no avail.what could cause the injector pulse to fade away?both sets do the same.will stay running when sprayed in the throttle body.im confused and have been doing this most my life!thanks for any input.