I have a 99 24v and I just put a raptor 100 on and it is real tough to start. I have to bump the starter and let the pump run for 20 seconds or so and i have to give it some pedal to get it to start. My VP was replaced mid 2008 and i just can't figure why it is so hard to start. My FP when i had the stock lift pump was 12psi at idle and 6-7 WOT and I didn't drive over 2500rpms on the stock pump. I installed the raptor but had not started the truck or anything and I threw a 1693 code as well as a low lift pump voltage code. Any help would be great. I live in FL so cold weather is not an issue
Hard starting
- Thread starter bama24v
- Start date
Billysgoat
The ANTI-BLING!
- Joined
- Apr 21, 2006
- Messages
- 10,694
Classic lost prime symptoms, you have a leak somewhere..
Checked everything and all was tight and good to go. I am thinking it is the overflow valve on the VP that is stuck open and so everytime I turn m truck off it is draining the diesel back into my tank instead of letting it set in the VP ready to start for the next time so that is why I am having to bump the starter to fill the VP back up. Just my thought so i am getting a new valve and am going to go from there.
Could be that or it could be from too much pressure while cranking. My old 01 did that with the fass hpfp, which is pretty much the same thing as your raptor.
The factory set up the lift pump to pump while the engine is cranking. If you have a fass or raptor or airdog, you are feeding the pump with alot more pressure than what the stock lift pump was providing. Too much pressure can sometimes cause these 24v trucks to crank for a long time before they start. The way you fix this is to find the wire that turns the pump on when you engage the starter and run it into your power window fuse. That way when you try to start the engine, the pump will not run while you are cranking. That second that the pump is not running will be enough for all that pressure to bleed back off. The pump will always be running when the key is on when you have it wired up like this.
Im not saying this is or will fix your problem, but it is something to look into. The way to tell if this is your problem is to pull the fuse on the raptor and then try to start the truck. If it fires right up with normal crank time, then this is probably your problem. The truck will start and run with the pump not running because the vp44 will siphon fuel from the tank.
For a detailed instructions on how to do this, do a search for " FASS Hard Start Fix"
The factory set up the lift pump to pump while the engine is cranking. If you have a fass or raptor or airdog, you are feeding the pump with alot more pressure than what the stock lift pump was providing. Too much pressure can sometimes cause these 24v trucks to crank for a long time before they start. The way you fix this is to find the wire that turns the pump on when you engage the starter and run it into your power window fuse. That way when you try to start the engine, the pump will not run while you are cranking. That second that the pump is not running will be enough for all that pressure to bleed back off. The pump will always be running when the key is on when you have it wired up like this.
Im not saying this is or will fix your problem, but it is something to look into. The way to tell if this is your problem is to pull the fuse on the raptor and then try to start the truck. If it fires right up with normal crank time, then this is probably your problem. The truck will start and run with the pump not running because the vp44 will siphon fuel from the tank.
For a detailed instructions on how to do this, do a search for " FASS Hard Start Fix"