96 michigan l90 start

[williambogner]

Im doing it properly. At least I think I am. There's two buttons in the cab. If I press that preheat button in the up position and click the key just past, it glows for about 50 seconds. I do this multiple times and she still wont fire. its getting colder up here and its effecting her much worse.

 

[funwithfuel]

What if you pump up the hand primer before starting?

 

[williambogner]

im going to try that this morning when i do it

 

[williambogner]

ok, good news. granted its not too too cold this morning, but it usually still takes a while to start. last week when i tried priming it, i must've not done it long enough. I went out there this a:m and primed it for a good 30 sec to a minute. I could here the fuel rushing through the pump and lines with air. She fired right off. So, this goes back to losing prime. Sounds like i have some lines/fittings/seals to replace. My next question is, is there any place that I could hook up a pump of some sort and try to see where I here air or fuel coming out vs just replacing stuff?

 

[funwithfuel]

I would strongly look at the two mentioned items. Lift pump and overflow. Now, since your primer pump is NOT all wet with fuel, I would not consider that as primary concern, I'd look more towards the overflow valve. Just my 2 cents.

 

[thepumpguysc]

IF you really wanna solve this problem, your gonna need a pressure gauge & another banjo bolt to adapt the gauge to.. The BB is a 14mmx1.5mm thread.. I've got a hundred of them IF you reeaally cant get ahold of one.. Drill & tap it for a fitting to fit your gauge & replace the INLET BB w/ YOUR test one.. hook up your gauge & SEE what the pressure reading is.. & IF IT HOLDS when you shut the motor down.
The overflow valve is usually the culprit if its below 40psi & drops like a stone..
You should also get a clear line from the parts store & put banjo connectors on it & replace your existing line from the filter head TO the injection pump.. That will SHOW YOU that's theres air in the system..
Just keep moving the clear line until you find the portion that DOESNT have air in it & move forward..
That's about all I got.. good luck..

 

[funwithfuel]

On top of the filter head, should be a plug in the same drilling as the bleeder screw. 1/8" BSPP iirc. Take that plug out and screw a 100 psi gauge in there . It's common to the injection pump inlet. That would accomplish what pumpguy is telling you to do without trying to score a banjo screw. He'll, if it's not a problem , leave it in there for future use. Just tape your threads.
Use the plug as a sample to match up your gauge. 1/8 BSPP is not the same as NPT. 1 thread per inch difference.

 

[williambogner]

ok, great guys. i appreciate you putting in the effort. Im going to screw the gauge into the top of the filter head and see what happens after I run it!

 

[thepumpguysc]

Whatever is easiest for ya.. as long as its after the lift pump & before the injection pump..
99% of the stuff I diagnose take the 14x1.5 banjo style connector, so that's why I suggested it..
drill & tap a spare bolt.. unscrew the old one, screw in the new "tool" & screw on my gauge hose, done..
Let us know how you made out..

 

[sfrs4]

Out of professional interest, can you see the engine serial number stamp, as from your pictures that looks a TD71G engine from a L120B, if you look where the block meets the head up to the right of the injector pump the engine model code etc will be stamped into the flat surface there.
should be something like TD71G * 285 * 12345

 

[williambogner]

ok folks. had some time after work today to tinker. I was picking up all filters and the overflow valve at the dealer and said fck it, i wanted to put a new lift pump as well incase that one ever crapped out, i'd have an extra during a snow storm. the overflow valve ended up being the culprit! went out there next morning, cycled the pre heater twice and she fired off like a cannon. The previous owner mentioned he never, ever, sprayed starting fluid to get it going. He did say on cold mornings, it was common to have to pre-heat 2-3 times. is that pretty standard? when its very cold, its not that enjoyable sitting there for 50sec cycles lol. Maybe the preheater is getting weak?

 

[funwithfuel]

Very common, if you're not listening and having fuel issues. When you turn on the preheat function, you should hear a clunk. That would be the large relay energizing. Depending on temperature, 45 seconds up to 2 minutes later you hear the second clunk. That's shutting off. The light is only minimum wait to crank.

Glad you got her squared away. Good job.

 

[williambogner]

ok, i will dig more into the solenoid on the pump. how does the preheater on the intake get engaged then? im assuming thats the other side of that switch on the dash?

 

[funwithfuel]

Sorry no. The relay for the preheat. You have a manual shut off cable , correct? If you follow the heavy cable from your grid heater at the intake manifold it will lead to the preheat relay.
The point is, during increasingly cold weather, the preheat time gets longer. A lot of people think that if the light goes out, the pre heater has shut off. Not the case. The pre heater can stay on yup to 2 maybe 2 1/2 minutes. Depending on the temperature. You don't want to mess with your pump now that she starts right up.
I only mentioned the on time so you would understand that you don't necessarily have to keep cycling the key and switch. Just listen and wait.
Again good job on following suggestions and fixing it yourself.

 

[williambogner]

ok, i will go out there tomorrow morning and listen/try. Supposed to be in the high teens for temps. Yes i have a manual pull cable for shutoff.

 

[thepumpguysc]

Thanks for the update.. Good job.. ya probably saved yourself about a grand in diagnostic labor & parts changers..