Help Problem after new Heads!

[panhead9]

I just installed new heads on a 94 blazer and am having problems getting it to run smoothly. I installed new injectors as well as glow plugs,after having a very hard time getting it started I finally got it fired Much cranking and many glow cycles involved,I have it running however it is running extremely rough I have jumped the lift pump and proved fuel into and out of the injectorpump return line. Upon initial startup i had much problem getting fuel from injector lines after rechecking wiring I thought I found problem almost seem like a miss Could I have mixed up the injector lines I have not found a firing order diagram in my book the fuel in the truck is at least six months old possibly this is problem? I will fill up with fresh fuel and conditioner tomorrow and will post any progress made again Also I did not have a t-stat in the truck today and could not getabove 100 or so I will install one tomorrow could temp being low be problem also? any thought appreciated thanks Leon

[tom.mcinerney]

Lack of thermostat definitely won't affect starting.
These usually prime well unassisted... but you can 'crack' open a couple fuel injector union nuts on each head {one at a time after started} until some fuel is seen to leak out --idea is to allow any air in line to 'bleed' out.

Some people have crossed up the injector lines...

[NH2112]

I've always found that unless you've seriously bent the injector lines taking them off, they line up almost exactly with the nipples on the pump when you put them back on. I'd replace the return line to the pump with a piece of clear tubing to see if you're getting air bubbles; you could also replace the return lines between the injectors with clear tubing to pinpoint where air's getting in.

Also, crack the injector lines one at a time and see if one (or more) of them doesn't result in a change in the engine's sound or vibration. It's possible you got a bad injector.

Lastly, don't rule out a head gasket problem, as much as you'd like to. If the upper radiator hose is pressurized immediately after a cold start, or if there are bubbles in the overflow tank, you probably have a head gasket leak. You can take off the coolant crossover to see which bank is leaking.

[panhead9]

yes I agree with you that it is very hard to switch injector lines they ae pre bent and very hard to change that is why I really dont feel this is the problem just a thought. I have not got up there today but will tomorrow also I forgot to mention the last time the truck ran was in january 05 so the fuel is old I will bring some fresh to add to the tank along with some conditioner and mabye a little Kero and also install the tstat mabye the computer has not reset itself without the temp gain and is running in the cold mode I will also crack all the lines when running to isolate the problem, or at least prove they are working just because injectors are new that does not mean they work. This truck is running the heath mechanical wastgate actuator with the heath chip as well as "F" intake gaskets to do away with the egr however i used to have the vac pump in with all connections on except it did nothing as I had the mechanical wastegate actuator now the pump is removed but i left the solonoids and electrical connected to them just no vac pump I am runing a 6.2belt. also I relocated the pump driver foreward to behind the driver side battery a couple years ago and have had no problem with that since moving it. Any other thoughts?

[twaddle]

Panhead,
First of all recheck the fuel pipe to each cylinder number location, as NH2112 said they line up almost exactly. for all the time it takes recheck it if you are in doubt.

Have you tried cracking off each injector pipe connector one at a time while the engine is running to ensure that the air is bled from all of them.
This may also identify which cylinder is missing if it isn't trapped air in the line.
Use a piece of rag to cover the spray of diesel.

It may be one injector with some air trapped in the line although they do usually clear eventually.

Good luck

Jim Twaddle
Biggar, Scotland