94 Q45 WONT START

[michaelt1wa]

I just spent 14 hours this weekend changing the valve cover gaskets, spark plugs, air filter, and fuel filter. When I went to fire it up, it only cranked over and did not start.I was very carefull with all the wires and sensors. Everything went back on where it was and I had no left over parts.Does anybody have an idea on what I missed?

[maxnix]

Fuel pump fuse?

Who knows, but you missed something.

[michaelt1wa]

I can hear the fuel pump come on until it builds pressure and stops. I think I'll check the fuel pressure anyway.I'm afraid I have to start tracking down an electrical problem.

[maxnix]

Check all connections first, including hoses just to be safe.

[elwesso]

I would assume you had to unplug the connectors on the passenger side. Id check those. A vaccum leak shouldnt prevent the vehicle from starting.

[maxnix]

Id check those. A vaccum leak shouldnt prevent the vehicle from starting.

But it sure can interfere with idling and running. If an electrical connection is overlooked, might as well double check the hoses also.

[michaelt1wa]

After work today I'll check and clean all electrical connectors and double check the vacuum hoses. I checked the fuel pressure, no problem there.
Modified by michaelt1wa at 4:50 PM 2/12/2007

[michaelt1wa]

After checking all my connections and not finding a solution, I went back to look at the pictures I took of the engine in case I couldent remember where thing went. I noticed the fuel lines looked like they were crossed. I swaped them and it fired right up. Now I need to find out why it is idling fast, about 1200 rpm.

[maxnix]

If no vacuum leak, turn screw on the IAC valve all the way in then out 2.5 turns.

Misadjustment of the IAC valve is common among mechanics that don't understand the VH45DE.

[Q45tech]

Over the years techs take the easy way out and just turn the air bypass screw out to raise the idle as the throttle plate and body get dirty from dirt getting thru air filter, pcv vapor, egr back splash, etc.

The 2.5 turns out assumes that the IAC has been cleaned to as new condition..............exact setting requires a Consult to view IAC solenoid Duty cycle and set it between 10 and 15%.

The ecu LEARNS the correct idle rpm and adjusts IAC and ignition timing and injectors to maintain it.