No Start

[nspctr1]

OK, I have a 92 998 A2 that is completely stock, 6.2 L motor that would start flawlessly since purchased. It would sit for a month or two sometimes without being started but it would still start with no issue. After the freeze in February, I"m in S. Tx., the truck refuses to start. I checked glow plug ohmage, made sure fuel was making it to and through the filter and that's about it. I get no smoke on crank which tells me its not getting fuel, right? But if its getting fuel pulled up through the filter housing and out what could it be? I've read that it could be a start box issue but not sure how to test it. OR a grounding issue. If it is a grounding issue, where are the grounds that need to be checked. Batteries are good, and have one last point to make. Before the freeze I put in about a quarter bottle of fuel treatment on a quarter tank of fuel. The fuel that comes out now is orangish in color and smells more like the fuel treatment than fuel. Is it possible that the treatment separated and is only being picked up by the pump and I need to add a few fresh gallons of fuel. It's got less than a quarter tank in it now as I don't keep much fuel in it due to not being able to drive/start it frequently.

 

[TOBASH]

Did you search for the many posts on this matter.

1 - check battery
2 - fill tank to 2/3 and see if this is electric pre-pump issue.
3 - alternatively pre-pressurize fuel tank to see if it is electric pre-pump.
4 - Crack injector and crank to see if fuel comes out.

 

[NDT]

Did you search for the many posts on this matter.

1 - check battery
2 - fill tank to 2/3 and see if this is electric pre-pump issue.
3 - alternatively pre-pressurize fuel tank to see if it is electric pre-pump.
4 - Crack injector and crank to see if fuel comes out.

What HMMWV has an “electric pre pump”???

 

[nspctr1]

Did you search for the many posts on this matter.

1 - check battery
2 - fill tank to 2/3 and see if this is electric pre-pump issue.
3 - alternatively pre-pressurize fuel tank to see if it is electric pre-pump.
4 - Crack injector and crank to see if fuel comes out.

Yes. If fuel is making it through the filter wouldn’t that mean the pump is working? Batteries are good as mentioned. Posts are mostly against pressurizing the tank due to chance of over pressurizing

 

[NDT]

I would start by verifying that 24 volts is present at the injection pump with the ignition on. Listen for clicking of the solenoid inside.

 

[papakb]

No smoke while cranking means the engine isn't seeing fuel.

You want to hear the IP solenoid "click" when the ignition switch moves to the "RUN" position. This is the valve that allows fuel to flow during operation and shuts the engine off when you shut down. They're notorious for jamming in the closed position after sitting. Luckily it's a simple job to replace the top cover of the IP to correct.

If that works then try unplugging the #54 wire from that same cover on the IP and then open the drain petcock in the left fenderwell and crank it up. If no fuel comes out then you could have 1) a cracked fuel line, 2 a bad mechanical pump, 3) an air leak on the water seperator body. Keep in mind that a full fuel tank can mask a bad fuel pump because the IP does have a little capability to draw fuel from the tank by itself. The symptom here is it will run til the fuel level gets down and then it won'd start.

 

[nspctr1]

When I turn the ignition switch on you can hear the clicking inside. I’ll check voltage at 54 if it’s not raining tomorrow. The truck has hardly ever run a full tank because I hardly have time to drive it due to work.

 

[Mogman]

When I turn the ignition switch on you can hear the clicking inside. I’ll check voltage at 54 if it’s not raining tomorrow. The truck has hardly ever run a full tank because I hardly have time to drive it due to work.

You should always keep any infrequently used vehicles fuel tank full at all times, especially in a rather humid environment such as San Antonio, grew up there BTW, give me a holler if you ever venture down south to the Corpus Area!

 

[nspctr1]

I would start by verifying that 24 volts is present at the injection pump with the ignition on. Listen for clicking of the solenoid inside.

I checked the power at the IP and there is 24 volts but I do not hear any clicking except from the inside of the cab.

 

[NDT]

I checked the power at the IP and there is 24 volts but I do not hear any clicking except from the inside of the cab.

Read papakb’s second paragraph above

 

[papakb]

nspctr1, Your going to need someone to turn the switch while you stand by the right side of the engine to hear the IP solenoid clicking. It isn't that loud and you want to make sure that what you hear really is the IP solenoid actuating. If you hold your hand in the top of the IP where the #54 wire connects you should also be able to feel it. If it clicks that's a good sign. This check means that the injector pump itself is allowing the fuel to get to the engine, if there's fuel to allow in.

The checks I mentioned before will check the fuel system functioning that gets fuel to the injector pump and they have to happen before the IP can do it's thing. One step at a time. I also suggest that you take a look at the TM. Here's where you want to start:

 

[Milcommoguy]

Many thing to go wrong with a no start condition. I have posted this before and it takes the guesswork out of failed or failing fuel pump issues in the shop or on the trail. Minimum delivery pressure of 4 PSI or replace per TM. (6-7 normal) Thirty bucks, thirty minutes and now you know.

Marshall Gauge 0-15 psi Fuel Pressure Oil Pressure White or Black, 1.5" Diameter Liquid Filled. NAPA or off the BAY.

Pictures show location and elbow / coupling to top of fuel filter canister. IMO This is the best thirty bucks spent to see what's going on with the system up to the IP.



Another way (little messy) is to crack the water separator valve and check for flow and stick in a gauge like shown below with a little splice / pointed tip thingie.



Follow the instruction shared by PAPAKB. Might be easier to hear the IP fuel on solenoid by... Leave the switch in RUN. Remove and replace the #54 lead at the pump while listening. Easier to here without the other clicking and clacking going on. It will be very faint "tick" IF not all gummed up, bent or broken or open coil, which can be checked with an Ohm meter. Typical good value +/- 24 ohms. (here's a tip. 24 volts, 24 Ohms. Draws 1 Amp +/- for you techie guys)

Help link,

https://gear-report.com/wp-content/uploads/2017/03/HMMWV%20A1%20Troubleshooting.pdf

These "NO STARTs" should not be leaving owners "on the side of the road dead" YES, there is a bit to it, as a couple of system come into play. I read OP stated "after the big Texas freeze" and that could be a clue to glow plugs or start box or ??? so more to testing to eliminate failing systems.

Follow the flow charts to conclusion for a "GO" Stay on track. Could be this, what about that or maybe this... is like being lost in the woods. Not meant to be smarty ass, just think SMART. Check the boxes and move forward. If owner / operator / maintainer a HUGE knowldge base will develop to keeping the little HumV happy.

No fuel, NO - GO. Fuel and NO glow, smoke and maybe GO. Reality, anything goes.

It is really hard to guess, CAMO GOOD LUCK.

 

[Action]

IIRC, you should get 1 pint of fuel out of the drain petcock (from fuel filter canister) for 30 seconds of cranking. I put 1/2 pint marker lines on an empty gatoraid bottle. Crank for 15 seconds should give 1/2 pint. Free and quick. Dump fuel back in tank. Easier with a couple feet of 1/4" hose attached to the petcock. If you get the 1/2 pint in 15 seconds, everything from there to the tank should be good to go.

 

[papakb]

Jason, I ran an 24" section of fuel hose down the edge of the fenderwell to keep it from getting crappedup with dripping fuel. Held it in place with a couple of "P" clamps.