muffman

I have a Volvo 8.1 HO with about 30 hours and just installed a set of lightning headers. When I tried to run it on the hose the starboard side injectors were not working. I have checked all connections and can't find anything that I might have disturbed. I have a Snap On Solus diagnostic computer we use here at the shop but I didn't know if it is possible to pull codes using the generic OBDII setting. Maybe I just need to fork out the dough for the Diacom software.

Pwrbt33

iTrader: (2)

It almost sounds like the plug for the injectors at the valve cover came unplugged or you lost an injector driver in the PCM. Also ck and make sure you didnt crush any wires between the header flanges and the cylinder head. Are you sure you lost the injectors and not the coils? Ck at the center of the valve cover between the 2nd and the 3rd coil pack and check the plug for the coils as well. Just a thought.

John S.

muffman

Thanks John I have spark at all 8 coils and connectors, pins and wires are all intact.

Dave_N

It would not be due to a failed injector driver, or open in a driver circuit, since each one drives the forward and aft cylinder on one bank and the center two cylinders on the other bank. In other words, only two cylinders per side.

How are you making this diagnosis (that all four injectors on the same side are failing)? Are you getting any engine alarms?

Dave

muffman

Dave, When I try to start the engine it will barely run for a few seconds and the exhaust on the starboard side is cold while the other will warm up. I have not put a noid light on the injectors yet. What your saying makes sense. I need to check for pulse and test fuel pressure tonite.

Dave_N

It looks like the way that the 8.1 fuel rail is designed the supply line feeds the port side of the fuel rail first, then the fuel goes up and over to the starboard side. If there is very low pressure, the port side may get a little fuel, and the starboard side no fuel at all.

As you said, check fuel pressure, if there is low pressure, check fuel pump fuse and relay. You are looking for 55 to 62 PSI, Key on, pump running, engine off.

Dave

Here's Johnny

Muffman....sorry I can't give you any help on the issues you are having with the header install....but this past winter I re-powered with a brand new Volvo 8.1 HO myself (I now have 53 hours from this season). I ask that when you get it running you post your results from this upgrade. I have been contemplating Lighting or CMI headers on my engine once the warrenty runs out. Thanks and good luck!!.....................John..

muffman

I ran a fuel pressure test and a with the key on engine off all I could get was 20 psi. Changed the filter and checked the old one for water and it was clean. I pinched the return line off and it didn't help either. I also checked the regulator for fuel in vacume line and checked to see if both pumps are running and they are. Ok so maybe its out of fuel so I made sure the filter was full and then tried to run it off a gas can still no change. I guess I need a pressure pump.