dennine3003

I put a 305 tbi in a 85 Camaro. The motor came out of a 89 camaro. Should I change the fuel pumps around too?????? Put the v-8 one in my 85 and take my fuel pump that is in it now (it used to have a v-6 in it) and put it in the other car that I put the v-6 in??????
I'm just wondering cuz my car is hard to start, it takes about 3 times to crank it and it finally starts. When I turn the key to on I don't hear the fuel pump run to prime the system to start. but after I do finally get it to start I then can hear the fuel pump run, even after I shut the car off.
I have already changed out the oil pressure switch(it needed it, it was bad), and the fuel pump relay. Now I have no idea what to do now. PLEASE HELP!!!!!!

Should I switch fuel pumps, I don't know.......... Any information would be great.

Thanks

dennine3003

The 20 amp fuse by the battery is fine, so I ruled that one out.

tom3

The V6 pump should run the V8 ok. In the Carter series the same pump is used for both the MFI V6 and the TPI V8s anyway. Why the pump doesn't come on with the ignition is probably a wiring problem, but it is running off the oil pressure switch for now. Don't know how relliable that will be in the long run.

Trickster

If it isn't priming when he turns the key, it sounds like it might be a problem with the ECM. That is where the fuel pump relay gets its signal to prime the system. Either that or as mentioned. the wiring from the ECM to the fuel pump relay.

dennine3003

Can I use a ECM from a 92 Camaro that had the same 305 TBI in it??????? or will I have to buy a new ECM?

Please let me know.

Danno

Sounds like a bad pump relay. The reason it takes some cranking is because the fuel pump has 2 voltage sources, the relay and the oil sender sw. Above 4-5psi the oil sender sw closes and applys 12 volts in a parallel path with the relay to the pump. It's a very common problem. You need to crank the engine with the starter to generate the oil pressure needed to energize the fuel pump if the relay or it's connector is bad. Rarely does the ECM cause this problem.

dennine3003

I checked all the wiring from the ecm to the feul pump relay and it's all good. Like I said before the fuel pump relay and the oil pressure switch is new. The ecm that is in it now looks like it came from a junk yard. I'm wondering if it could be the ecm. It's the only thing that I can think of. The ecm looks pretty rough anyway.
So let me know what I should do.

dennine3003

sorry for taking so long to reply. It was the ecm, I bought a new one and it worked. Thanks for all the help guys.