Crank but no start
Crank but no start Hey guys,
I'm running the HP EFI system on my lq4 swap. Each night I've been disconnecting the computer wires from the battery because the fuel pump has been kicking on and draining my battery. Today when I reconnected the wires the starter cranked but the engine just would not start. I can hear the fuel pump and injectors prime when I first turn the ignition to on. The fuel pressure sensor is telling me that the pressure at the rail is normal. I read that it could be a cam or crank sensor issue but I am getting an rpm reading when the engine cranks so I don't believe that's the case. The fuse between the battery and relay checked out fine. I also figured since I've been trying to start it a lot today the engine might be flooded. I pulled a spark plug and it was completely dry. It was running great last night so I'm not really sure what would've changed since. Any help would be appreciated. Thanks
I'm running the HP EFI system on my lq4 swap. Each night I've been disconnecting the computer wires from the battery because the fuel pump has been kicking on and draining my battery. Today when I reconnected the wires the starter cranked but the engine just would not start. I can hear the fuel pump and injectors prime when I first turn the ignition to on. The fuel pressure sensor is telling me that the pressure at the rail is normal. I read that it could be a cam or crank sensor issue but I am getting an rpm reading when the engine cranks so I don't believe that's the case. The fuse between the battery and relay checked out fine. I also figured since I've been trying to start it a lot today the engine might be flooded. I pulled a spark plug and it was completely dry. It was running great last night so I'm not really sure what would've changed since. Any help would be appreciated. Thanks
Teching In
Joined: Jan 2014
Posts: 20
Likes: 1
I am not sure where your no start problem lies at the moment, are you not getting any diagnostic codes? Also the fact that the fuel pump has just been coming on on its own accord tells me there is either something wrong with the ECM or very wrong with the wiring.
I had the fuel pump problem before and it was a ground on the racetronix hotwire kit. I think I fixed it but just as a precaution i disconnect those wires until I know for sure. I'm still learning how to use the holley software, so I don't really know how to check for errors, but it seems like all the values are what I'd expect to see from it.
Teching In
Joined: Jan 2014
Posts: 20
Likes: 1
Yeah, the Holley ECM kinda throws a wrench in my diagnostic process because i don't know what things it checks and would throw a code for. With a GM ECM a bad cam or crank sensor would almost certainly throw a diagnostic code, but the Holley one may not.
Is it trying to start at all or just spinning? You might check and make sure you got all your ground reconnected, especially the ones for the coils and injectors.
Is it trying to start at all or just spinning? You might check and make sure you got all your ground reconnected, especially the ones for the coils and injectors.
