vorgath

I ran a few tests today, regarding my fuel pump circuit problems, with it being Code 54. Did everything with the test light, according to the factory manual for a 91 Camaro.


Final test for me was to conenct a test light between harness connector 465 (I connected by the relay though, would it even matter, considering it's still 465, i.e. green/white wire) and ground. Ignition off for 10 seconds, ignition on after that, result was no light.

Which indicates the title of my post, i.e. 465 open, shorted to ground or faulty ECM.



I also have a Code 42, which I haven't run the tests for yet.


I may have friend the fuel pump driver I guess, but .. is it possible ???? What happened is I supplied a ground cable hooked up to a switch, and spliced it into the green/white wire by the relay, i.e. circuit 465. Supplying a ground, would that FRY the fuel pump driver, i.e. A1 on the ECM ???


Code 42 happened when I replaced the relay connector.


Is it possible to fry the ECM by supplying another ground to it ? And oh btw, that ground has been disconnected a long time ago though.


I don't know if I'll be able to make it to the junkyards to get another ECM if I need one.

vorgath

Is it safe to drive, gently, without pushing the car too hard, while having Code 42 ? Last I drove it was just around the block, to park the car. Worried about the timing deal. But I may have to drive it to the junkyard to get parts.

thunderstick

just wondered why you would splice that grn/wht wire to a ground... that wire is what sends the signal to the relay to power up the pump.

vorgath

I was doing the manual fan switch deal, had left my books at home, and well, confused the green/white wire from the fuel pump relay with the green/white wire from the fan relay.


Would it be safe to drive the car for now .. gently ?

Vader

FWIW, you need to power down the ECM/ignition for TWENTY seconds before the fuel pump cycle will repeat, not ten seconds.

Vader

In grounding the fuel pump relay output, you grounded the collector of the output transistor in module U25. Unfortunately, there is minimal overcurrent protection for the relay drivers in the 730 ECM. If waiting 20 seconds between attempts does not produce a voltage change at terminal A11 (the fuel pump relay driver), you may have damaged the hardware. Unless you can isolate and replace this output driver, you may be better off with a replacement ECM.

Driving the car in this manner should not produce any problems, since the pump should receive power through the auxilliary oil pressure switch. It will likely take a little more cranking to start the engine, since oil pressure will have to build to at least 7 PSI before the pump runs.

vorgath

Well I managed to get rid off Code 42, some wires/connectors must have been somewhat loose.

So right now I'm again driving by connecting a hot wire to the gray wire, circuit 120, on the relay. I also did what got posted to me, i.e. doublechecking the relay by measuring the resistance, yup 60 ohm alright.

I got the advice to replace the tranistor at the fuel pump drive on the ECM, but not sure where to get the transistor. Radioshack doesn't seem to have the "correct" one.

Going to try to find some ECM's at the junkyard, but chance is somewhat slim, due to me needing 90-92 TBI ECM, and let's face it, people rob all cars off everything valuable there.

I still haven't found the wheel lock removal adapter for my stock Z28 style wheels grrrrrr, car never came with one.