rongi3

Can anyone tell me if they have had the following problem on their 4cyl TBI: 2.5 l iron duke? I'm not getting the initial spray of fuel when the ignition key is first turned on to the TBI. Node light shows the signal. and car will start and run with a spray of gas into the TBI. My friend believes it could be the oil pressure sending unit not working. What do you smart people think?

hmmm:

LiveIt!

I couldn't find a wiring diagram specific to the 2.5 TBI Iron Duke, but if it follows the same basic wiring of the 2.8 MPFI then the oil pressure sending unit shouldn't have anything to do with it. That's for the oil gauge. The oil pressure SWITCH, though, is like a backup for the fuel pump relay, it'll keep the fuel pump running as long as there is oil pressure, If your car has the electric fuel pump in the tank. You should check and make sure the in-tank pump is still working. I'm unfamiliar with dukes so if your car has the two 20 amp fuses in weatherproof cases near the battery, check and make sure they're good. They control the ECM and electric pump. If those check out go to your ALDL connector under the dash and ground port A to port G, that should force the pump to run. If it runs you'll know the pump is good, move on to troubleshooting the fuel pump relay and oil pressure switch.

Hopefully this will help you some

rongi3

here is the question is there suppose to be and initial spray of fuel into the TBI when the key is turned on and if so what electrical part causes it to spray, the fuel pump relay. oil preassur switch or the ecm?

LiveIt!

Yes, at least that's how it is with my 2.8. The ECM runs the relay for a second or two to prime the system, then after the car is started all 3 work to keep it going. ECMs don't usually go bad, so if you're not getting a prime spray check your fuses first. Did you try testing the pump? How'd that go?