Reviving a 1990 F250

[IDIBRONCO]

No idea.

 

[Selahdoor]

As long as the throttle moves, the governor (minimax) moves. What sticks is the metering valve in the back, this is the fuel “gate” so to speak. It is controlled not by the sliding rod which is the minimax governor, but by the black linkage on the side which runs to the front of the pump and actuates on the flywheel. The idle spring of the minimax pushes on the end of the linkage to overide the flyweights in certain throttle conditions, and the fss arm on the solenoid slams the metering valve shut when the key is shut off. Usually they stick in the off position from sitting, the fss still will click with it in this position. The top cover is sealed by a square cut o ring, be sure it’s in its groove when you tighten the cover back on.

Wes, mine was stuck solid with the crud. Yet my throttle moved just fine.

And yes, the governor itself was stuck. Didn't take much to unstick that. I'm guessing what gave me the most trouble as far as getting everything to work smoothly, was getting that metering valve to go smoothly through it's entire range.

I'm not nearly the expert on this that Wes is, but you did say that you got fuel to all 8 injectors. Assuming that you're getting enough fuel volume of to the injectors (had to tell by just cranking) I'd guess that you don't have something sticking in the pump. If all else fails, you could try chaining this truck to another one and try pull starting it assuming that this is the 1990 with a ZF5 in your signature. At the shop I used to work at, one time we put a 6.9 complete with rebuilt pump and injectors in a 1984 or 85. We tried EVERYTING to get the thing to start. It had fuel to the injectors. We sprayed WD-40 into the intake, then we went to ether. Nothing. We would charge the batteries when they got low. Still nothing. Not one cylinder would hit. Finally, we got tired of that crap and chained it to our shop truck. The shop foreman sat in the customer's truck, I drove the shop truck. We weren't even out of the parking lot when the foreman dumped the clutch and the truck fired right up like it should have in the first place. It started fine every time after that. It started fine in the morning after sitting all night and being cold. The customer never had any starting issues after that.

IDIBRONCO, I'm thinking that if the metering valve is sticking at any point in it's range of movement, it might let fuel through. Just not enough?

 

[IDIBRONCO]

IDIBRONCO, I'm thinking that if the metering valve is sticking at any point in it's range of movement, it might let fuel through. Just not enough?

You very well could be right. That's why I said that it's hard to tell by cranking.

 

[chillman88]

Timing that far off?

Could be but my experience tells me otherwise. My pump was fully retarded when I got the truck, it fired, just took alot of cranking. My timing is right on and my pump is fully advanced now. Unless he's off a tooth or more, I don't think that would prevent actually starting. Make it harder yes, but not prevent it entirely.

 

[BeastMaster]

Geez...grasping at straws here...weak starter motor? Weak battery? A seasoned ear would have detected that before I got the first three letters typed.

If compression isn't fast enough, it won't hit temperature to ignite. I'm puzzled. Compression good, fuel good, yet no ignite.

Could the injectors be peeing out a stream that's not sufficiently atomized?

But it seems so unlikely all eight of em are doing it.

Use a clamp on DC Ammeter to verify the proper current is going to the glow plugs, and your truck is not conspiring against you giving you theater instead of a start?

https://www.amazon.com/PDI-CA-600-Handheld-Current-Clamp/dp/B00X3GDW4O/ref=mp_s_a_1_6

Something as stupid as a bad connection on the ground strap between the engine block and battery negative? Just drawing straws here...

And no, I have no idea why the words engine block are being linked to Amazon. It's not showing up in my edits.

 

[Selahdoor]

Could the injectors be peeing out a stream that's not sufficiently atomized?

Or letting go at such low pressure that it is simply drowning the cylinders?

But it seems so unlikely all eight of em are doing it.

Agreed. Maybe it only takes three or four?

Something as stupid as a bad connection on the ground strap between engine block and battery negative? Just drawing straws here...

Good point.

 

[BeastMaster]

Maybe the IP is worn and not developing sufficient pressure for proper atomization? Any easy way to test for that? I hate shotgunning like that...too much work.

They may spray fine into 1 bar ambient, but are they spraying into 18 bar or so in the cylinder?

Anyway, all I'm doing is saying whatever comes to mind... It may not make much sense or be redundant. Just hoping something may trigger off something useful.

 

[chillman88]

At this point, personally I would vigorously clean the ground cable attachments to the block to make sure they are making the best possible contact. I would do the same with the positive cable to starter connection. After that I would pull the starter and clean where it connects to the block very well (this is your starter ground). If that doesn't work I'd be VERY tempted to try a different (new/reman) starter. I've had a few times where the starter sounds fine but just isn't quite spinning fast enough to fire off.

 

[Va_Mike]

wow lots or stuff to respond to. I really appreciate all the input because this truck is starting to drive me crazy (my fault for buying a cheap one I know)

Lets see if I can answer some questions.

The batteries are new and charged the day before I worked on the truck ( I did have them tested last time at the auto parts store and they test great). The starter seems to be turning the engine over fast but the rpm gauge bounces around so I don't know exact rpm. It does spin a lot faster when I spray some brake cleaner in it. But it does sound like it is spinning as fast as my V8 Land rover. I have had the starter off the truck and it is a reman with a sticker still on it and it looks relatively new. I also cleaned all the cables and the mounting area well before putting it all back together. Next time I try I will hook my rover up to it and give it some more starting power and see what it does.

The throttle moves but not as smooth as I would expect. I will definitely be pulling the top off the pump and checking things out in there. I do have concerns about the pump being worn.

I can fill the fuel filter with ATF and let it sit, but will that do more than the Diesel Clean in high volume? I currently have a 1/4 quart of diesel clean mixed with 5 gallons of fresh diesel and a little 2 cycle oil. I have been trying to run off of that to eliminate bad fuel in the tank being the problem. That has been sitting in the system since Saturday.

I am getting power to the FSS. If I remove the cable I do hear it click.

I do get some white smoke and if I use the brake cleaner I get lots of smoke, the starting fluid I get a little smoke but not as much, just slightly more than cranking the truck normal.

I do currently have the glow plugs disconnected because the push button was not wired properly and melted a cable under the hood when I hooked it up. I will try and run another cable I guess I will go up a couple gauges and see if it helps. Anyone have a wiring diagram of how the push button setup should be wired? But I am in VA and the temps have been steady in the upper 90's so the truck is warm.

Someone also did a crap job running wire under the hood to stuff. It is all red and just going wherever. I know what some of it is doing by process of elimination but some of it I still don't have a clue what it does.

 

[Thewespaul]

You got smoke, so the pump is making pressure and atomizing the fuel. You either don’t have enough speed or compression to ignite the fuel. Plug in the block heater for a few hours, then crank it connected to a running engine and it should start.

 

[Selahdoor]

I'd go with Wes' advice here.

If all else fails, do a compression test.

 

[BeastMaster]

I live in Southern Commiefornia. It gets hot here. But I can tell you my 7.3L IDI is hard to start without the glow plugs.

With them, it starts damn near immediately.

Even in the summer.

I would go after those glow plugs....all they do is trip off combustion. Once the engine catches, now you have ample heat.

 

[IDIBRONCO]

I was going to go with the glow plugs here too. IF your engine is running fine, which yours isn't at this point, then you can start the engine without glow plugs IF it's hot AND the sun's been shining on the hood all day. I have done it just to try it, but I wasn't trying to start a truck that hasn't been running in years with an injector pump that's in unknown condition. Get the glow plugs working again and you should have it running. Of course you can test the running thing by listening to Wes and plugging the truck in for a couple of hours. Unless your block heater doesn't work. Then you'd better go back to the glow plugs.

 

[Va_Mike]

I definitely want to fix the glow plug system and get it working. Long term I will replace it with Wes's system. Does anyone have a wiring diagram for a push button system so I can wire this up properly so it doesn't melt again?

 

[BeastMaster]

Anyone know any reason why Mike can't safely attempt a start if he wires the hots of all his glow plugs together, then powers the group for 10 seconds or so using a jumpstart cable? Then engage starter motor immediately after disconnecting the power to the plugs?

He's posted his glow plug circuitry is in disarray, and I think this may give him a quick cheap way to confirm our suspicions.

All it will involve is the eight glow plug wire ends together,..maybe with one of those slotted bolt clamp thingies commonly found on power wiring grounds, and a common jumpstart cable.

Or, maybe that part of the wiring is intact, and all he needs is a "200 Amp screwdriver" across the two main relay contacts on the glow plug control module for the needed 10 seconds or so?

Personally, my bet is that he will start. At least enough to burn enough fuel to reveal if there are any more surprises in the fray.

If this doesn't work, compression is whats left, and that's a lotta work to even measure, that is unless you are familiar with these beasties to hear it in the rhythm of the start.