Hard Start, What Now?

[TestDriver]

I've owned this 94 for two months now and the whole time it's been hard to start. The usual suspects have been replaced. I put in new hose on the fuel return side, new o rings on the injectors and replaced the 5 bad glow plugs it had. Still, it's hard to start.

The other thing is, before replacing the hose and o rings, I installed a 12v pump to get around the hard start issue. It did not help much if at all. Before the hose and o ring update, I did hear a gurgling over the tank when I ran the 12v pump before startup. I took this to be air. However, the gurgling would stop and I'd still have a hard start.

What else can I look at?

 

[jeffgordon24]

are you sure the starter is turning the motor fast enough ,if not it will always be hard to start.Try hooking a charger or booster pack while starting

 

[Mat J]

Also check your compression, if you have low compression that will cause a starting problem. I think some auto parts stores rent out a tester, make sure its for a diesel.

Another thing would be to get your timing set correctly.

 

[Ironman03R]

Glow plugs, batteries, starter and Air will all cause hard starts. Make sure all battery connections are clean and tight, and BOTH the batteries are GOOD and that the starter can turn the engine over fast enough. Recheck all your glowplugs and the GP solenoid, if there is a new plug burnt out you may have a timing issue. AIR. Check all you fuel lines enen the ones ontop of the tank, since your in MI, I'm sure your familiar with rust .
If I have even one plug out, my truck will start hard even on a warm day.

 

[gonecrazyi]

My old 7.3 was the same way, turned out it was worn out an nolonger had the compression needed to start (explained the miss lol).

I dropped a great running 6.9 in and it starts right up with the glowplugs and 1 battery. I mean I hit the key and its running within about 2 secs with no long cranking of the motor. This is with my number 2 injector leaking fuel and with the mechanical lift pump still being used.

My previous motor would bleed down when it had bad orings but once those were fixed all was well. But as the motor got up to around 160,000 it became harder and harder to start even when it wasnt bleeding down. It took 20 seconds of cranking in the morning to get it to fire and always required glow plugs even when it was hot.

Also as stated above, timing can effect how quickly a motor fires up. Mines slightly advance and it does make a world of difference.

 

[TestDriver]

Thanks for all the replies.

Like I said, I replaced the bad plugs and they all show 1 ohm or less now. While replacing them, I also replaced the relay on top of the controller. Now, the wait to start light stays on for a good 8-10 seconds before going off. Previously, it just lit up for a second.

The low compression might be a good place to start. It's got 173k on it now so it might be low. Power is good though and it fires right up after the initial hard start even if I turn it off immediately afterward and the temp is in the 40s. This is why I thought it was an air issue with the return lines.

Cranking speed is good. The batteries show less than 6 months old and the connections are all good. It cranks way faster than my neighbor's two Powerstrokes.

How can I advance the timing safely without having a tool to check where it is at now?