1992 7.3 IDI Wont Start.

Yes i know there are many threads over this. But none have given me information to get it started. I will add a link of a video explaining everything. Bought the truck none running, I have replaced the injectors and return lines. The fss is good and clicks, what I don't understand is that I'm getting fuel through the injection pump to the injectors but theirs no white smoke, at all.... I haven't checked the compression yet but I'm still convinced there is a fuel problem since I am getting no smoke at all. Any tips would be greatly appreciated.

do you have flow thru the injectors?
Check,
Cranking speed (12.5-14 volts stattic\running)
no power to glows
fuel pressure at filter head

Crack open the lines at the injectors , Maybe even check the lines at the injection pump itself , to see if your getting fuel to and from .
Next I would give that intake a shot of starting fluid to see if it starts ,
if it starts then you have compression just a fuel issue, bad IP,
also the injector lines could be clogged if that truck has been sitting , unlikely

Be careful running an electric AND mechanical lift pump. The lift pump is just a diaphragm pump and if it ruptures your electric pump will fill the the pan with diesel.

I have the identical truck. 92 7.3 NA

Mine sat for at least 5 years before I got it. And it took me a while to get mine started, as well.

You need three things to get these trucks started. Fuel. Air. And compression.

You are getting fuel at least as far as the filter. I would bet that you are getting it all the way through. But the simplest way to be sure is to crack the lines at the injectors, and watch for fuel at each injector. It doesn't pour out of there. It kind of dribbles.

If you are getting fuel at the injectors... Remove the glow plugs and do a compression test.

You are obviously getting air, with the air filter housing off.


Now here is where I amend the rule of three.

You also need two more things, to get these trucks started...

It has to be warm enough. GPs have to be working, or block heater has to be working and be plugged in a couple hours or so before start.

And... Speed. As in, the engine has to be turned over fast enough.

This last thing is what caused me to take so long to get mine started.

I had batteries that seemed good. The took a charge. They turned the engine over at what SEEMED like an adequate speed... etc.

The day I got it started, I finally decided to just hook up another running vehicle with jumper cables. (A CAMRY, no less. Tiny car, tiny battery.)

Let the camry run on high idle for about 20 minutes, while hooked via the jumper cables to the truck. Then run the throttle up a bit more, while trying to start the truck.

BAM!! Started right up!!! For the first time since I got it home. I had been working at it for well over a month, I think. And all the stuff I had done to it probably contributed to getting it started. Pretty much the same stuff you have done. So none of that was wasted effort. But yeah, just getting it to turn over FAST enough, was what got it started the first time. I put brand new batteries in it, and eventually a new alternator... And have not had that problem since.


One last... You said new fuel filter... How about the fuel itself? And if all else fails... You can pop the top off the IP, and check that the governor isn't stuck. Mine was making the clicking noise, but the governor was stuck. I took the top off. Moved the governor with my finger. Back and forth, until it moved freely on it's own, and returned freely when I moved it and let it go.

When you are done with everything, and have gotten it running... Fill that filter with ATF. Run it until the ATF has filled the injectors, turn it off, and let it sit for a while. Overnight. A week. Whatever. That will help clean out the injectors, and the IP and the lines as well.

homelessduck said:

Be careful running an electric AND mechanical lift pump. The lift pump is just a diaphragm pump and if it ruptures your electric pump will fill the the pan with diesel.

Click to expand...

Wurd!!

I have an electric and the manual, together, as well.

I used check valves inline with both. So that neither could pump back to the other.

Wes has suggested a check valve below the mechanical pump, for quite a while here. And he is correct.

But I had both the mechanical and the electric, and only two check valves. So I plumbed the two check valves inline AFTER each pump. That keeps the fuel flowing to the filter, instead of letting it go back to or through either of the pumps from the other one.


I like having the electric pump in there because if a leak develops, that electric pump builds up the pressure and fills the filter, lines, IP and injectors, without having to crank the engine over to get to that point.

"The guy said he had it running." Always take that will a grain of salt. After all, he was selling the truck. If you didn't actually see it running, then that statement is open to question.

You're convinced that fuel is getting to the injectors, but there is no white smoke. That would indicate that perhaps the fuel isn't getting THROUGH the injectors. You said you replaced the injectors. Important question. Where did you buy the new injectors? Not all injectors or injector sellers are created equal.

The cranking speed is important on these engines. They must crank at a sufficient speed to build up heat in the cylinders before they will ignite. Are the batteries in good shape? Try temporarily hooking up jumpers to the passenger side battery. When cranking be careful. Do not crank more than 15-20 seconds or you'll overheat the starter and burn it out. Wait 2-3 minutes between cranking sessions to allow the starter to cool. Of course, the starter itself may already be burned and not cranking fast enough.

Once you have fuel coming out at an injector tighten it down.

Report back when you've tried everything suggested.

EDIT: Selahdoor and I were typing at the same time. He sniped me, and had a bit more information.

try starting fluid or the old gas on a rag to see if it would even have compression to start. then you work your way to fuel related issue

Selahdoor said:

But I had both the mechanical and the electric, and only two check valves. So I plumbed the two check valves inline AFTER each pump. That keeps the fuel flowing to the filter, instead of letting it go back to or through either of the pumps from the other one.


I like having the electric pump in there because if a leak develops, that electric pump builds up the pressure and fills the filter, lines, IP and injectors, without having to crank the engine over to get to that point.

Click to expand...

I think this is actually a really good idea. I'll probably do it to mine some day too.

Selahdoor, I also like your idea of having both pumps. Do you have a post on here somewhere on how you set it up? Or could you just elaborate on the setup?

He describes the components he used here:

https://www.oilburners.net/posts/1047333/

and discusses the installation further in the thread. I don't know if he discussed his plan earlier in the thread.

Back to the original posting: once you have verified fuel, you need to verify how fast your starter is spinning the engine. Do you have new batteries and have you really inspected your harness and battery connections?

Lastly, use a lot of caution before resorting to ether. I won't use it on an IDI ever, but opinions vary. Just know that it can cause lots of damage, particularly if your glow plugs decide to pre-ignite the either when one of your pistons is still traveling upward towards the compression to ignition event. No matter how hard your no-start is to diagnose, it will be a lot easier than adding a bent connecting rod.

Again, verify that you are getting fuel at the injectors and then try to check your cranking speed. Newer gear reduction starters and good batteries/cables/connections spin these engines to 400-500 rpm. After that you are really down to doing a compression test to verify that you have adequate compression.

Good luck to you

lonnoid said:

Selahdoor, I also like your idea of having both pumps. Do you have a post on here somewhere on how you set it up? Or could you just elaborate on the setup?

Click to expand...

Here is a pic of the way I set mine up.

NOTE: The check valves are backwards in this pic. I never noticed until after it was too late. (The parts were already installed. Not going to uninstall, just to take another picture.)


*The fuel comes in from the left.
*Goes to the first Wye.
*From there, through each fuel pump.
*Then through the check valves. (Which SHOULD have the arrows pointed at the second Wye.)
*Then, to the second Wye.
*And from the single outlet on the second Wye, straight up to the fuel filter.

I used a green electric fuel pump from o-reiley's. And I put it in the doghouse, on the wheel housing, instead of down on the frame next to the tank. It is designed to push, not pull. But for this purpose, it does the job just fine.

Had trouble starting my IDI turbo. Replaced glow plugs, installed new hoses/o-rings/olive seals, installed electric fuel pump, bypassed the glow plug controller using a manual button on the dash. Still had issues. Final culprit turned out to be the glow plug circuit solenoid. It was clicking but not making contact internally. Picked up a nd installed new solenoid. Eight to twelve seconds on the manual glow plug button and she fires immediately regardless of outside temperatures.