Air intrusion on 1990 7.3L f350 with banks turbo

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
Most of us just buy from Russ (Typ4), Classic Diesel Designs, Conestoga Diesel, or R&D IDI Performance and let them worry about the nozzles. You also may be able to get ahold of one of them and have them tell you where to get new ones.
 

danda

Registered User
Joined
May 17, 2022
Posts
72
Reaction score
18
Location
CA
Thx, yeah I checked out the online shops for each of these. Looks like Classic Diesel and R&D are out of stock.

So the question now is should I buy new or reman from Russ or Conestoga. It seems the pricing works out similarly.

For example, rockauto has brand new:
GB Manufacturing: $35
Standard Motor Products: $44
Delphi: $55.

So for a set of Delphis, that is $440.

Ordinarily I would just buy the new ones. But I've read a few things indicating that quality is not what it once was, even for the Delphis.

So...

1. what do y'all think of GB vs Standard Motor Products vs Delphi?
2. new vs reman -- from a trusted forum member.
 

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
I've used both Mel and Russ so I don't have any recommendations there. I'm not sure that there are still new injectors available anymore despite what the listings show so I'd be suspicious of them. I would stay FAR away from the one from anyone except for the four that I mentioned earlier.
 

danda

Registered User
Joined
May 17, 2022
Posts
72
Reaction score
18
Location
CA
Thx, for now I've sent an inquiry to R&D asking if they can make up a set of their stage1 injectors. If so, that would be a brand new set with an extra performance boost at a reasonable price... fingers crossed.
 

danda

Registered User
Joined
May 17, 2022
Posts
72
Reaction score
18
Location
CA
Update:

I installed new/reman injectors from Russ. These have new nozzle tips. I pop tested them first and they all tested right around 1800 and did not leak from the tips. yeah!! I noticed that 5 of the 8 actually did leak/weep a small amount from the threads of the cap/nut that holds the nozzles on the injector body. After consulting with Russ, I snugged these up a little bit more, re-tested and the leak went away. Maybe it would have been fine to install them as received, but this gave me extra peace of mind.

I reamed the carbon off the injector seats and brushed out the bores with 12 gauge shotgun brush.

I installed a new glow plug harness. It turns out that I ordered the stock harness when I actually need the turbo offset harness. whoops! Well, I was able to make it work, but its kinda ugly. Also, it's real cramped in there with the turbo and I was unable to get the old wiring harness out easily, so I just left it. Kind of a mess, but whatever.

I installed new hard line for injector #7 that I got off ebay. Fit perfectly. And new return lines/caps.

With everything back together, she is running again, and no obvious leaks, so that's a step forward at least.

I have not yet re-timed the injection pump.

Observations:

1. Exhaust now smells like burnt diesel, I don't notice the unburnt smell anymore.

2. The glow plug relay is quieter. It clicks once, stays on a bit longer than before, clicks off, and stays quiet. It used to click 2-4 extra times after WTS went off.

3. The truck started up this morning at 6:00 am after sitting about 12 hours. Took about 4 secs of cranking. (I was hoping for less). Once it fired, it stayed running, but had a quite rough idle until I gave it some throttle.

4. There was some blue/grey smoke this morning until it warmed up a bit. I gave it some throttle and it eventually cleared up. I had given it a little workout yesterday before shutting down, so was disappointed to see smoke this morning.

I guess the obvious next step is to re-time the IP.

I need a timing meter though. Unless there is someone nearby? South Bay area, CA.
 

Big Bart

Tow&Slow
Joined
Dec 22, 2020
Posts
1,481
Reaction score
950
Location
Newport Beach, CA
If you are up for a trip to Costa Mesa I would be willing to help you time it. If so private message me with your phone number.
 

danda

Registered User
Joined
May 17, 2022
Posts
72
Reaction score
18
Location
CA
If you are up for a trip to Costa Mesa I would be willing to help you time it. If so private message me with your phone number.
hey thanks Big Bart! If I lived in southern CA I'd take you up on it.

That's a bit far from here though and actually I ordered a DTI tech time, which is arriving tomorrow. (Plus the truck is non-op'ed right now.)
 

Big Bart

Tow&Slow
Joined
Dec 22, 2020
Posts
1,481
Reaction score
950
Location
Newport Beach, CA
hey thanks Big Bart! If I lived in southern CA I'd take you up on it.

That's a bit far from here though and actually I ordered a DTI tech time, which is arriving tomorrow. (Plus the truck is non-op'ed right now.)
No worries, your are better off having a timing system, you will use it again and again. FYI every IDI owner should have one!

Most shops do not have one, so to get most shops to time your truck would mean loaning them one.

Here is some info on how to time your truck that might be helpful.

 
Last edited:

danda

Registered User
Joined
May 17, 2022
Posts
72
Reaction score
18
Location
CA
Progress: I finally had a little time yesterday/today to mess around with the 7.3 again.

I installed clear tubing between the top of IP and the main return line pipe. I already have another clear tube between #1 injector and the fuel pump housing.

After running the engine for a while and shutting off, after a few minutes I start to see bubbles come up to the top of IP. And eventually also some up to the fuel pump housing.

Ok, not earth shattering. I was expecting this. The problem has been that with the banks turbo installed I can't get to the very back of the engine to inspect the return line tee(s). But after removing air filter housing I was able to shine a light back there and saw enough oil (diesel?) grime to suspect a small leak. It's still not possible to get a good view or put a wrench on anything though.

Also, the return line from passenger side injector closest to firewall goes down into the valley beneath the turbo and disappears. I believe there must be a *second* tee down there into the main return line, but can't even see it. super frustrating.

So, I got a bright idea. Or rather two.

1. To confirm the leak location, I cut the return line under the truck and put a plug in it. Then I removed the line at top of IP and blew compressed air (20 psi) through it. Sure enough, I could hear air coming out where I suspected and see it blowing small debris back there. bam! problem identified, after all this time.

2. I'm going to bypass the factory return lines which are impossible to work with. I will simply run hose from the IP top (return) to the return line at bottom of truck, and tee the front driver side injector into it. Then I will route together the returns from the two injectors closest to the firewall so that the passenger side injectors have a return path. This puts everything up where it is easy to work on it and identify any possible leak in the future. And I only need to change out one injector cap.

Ok, so that's the plan for tmw. Hopefully my hard start problems will soon be a thing of the past and the return line system will be cake to troubleshoot and work on.

Anyway, I hope this helps someone down the road. I haven't really seen anyone talking about the return tee(s) at back of engine being the problem, or hard to access because of turbo, or plugging the return line and using compressed air to find the leak.

The return lines on this engine are conceptually simple, but impossible to access in practice without removing the turbo entirely which makes it a big PITA. It's high time for simplification.

edit: I also removed the outlet at top of IP pump because I learned there is an o-ring inside there that sometimes goes bad. My o-ring looked perfect, but I replaced it anyway, and used thread sealant when replacing the two threaded pieces.

edit: here is a video of another truck with a banks turbo that also has leak in about the same location as mine. But the leak in the video is much worse than mine, so it is obvious.
 
Last edited:

IDIBRONCO

IDIBRONCO
Joined
Feb 5, 2010
Posts
12,235
Reaction score
10,925
Location
edmond, ks
I believe there must be a *second* tee down there into the main return line, but can't even see it. super frustrating.
That would be on the back of the driver's side right before the line that returns to the tank.
And I only need to change out one injector cap.
Plan on doing all of the o rinds on that side. Once you disturb another return cap, those o rings will most likely start leaking as well. Even a bump on a cap can start a leak.
 

Cant Write

Full Access Member
Joined
Sep 29, 2021
Posts
866
Reaction score
719
Location
Placerville CO
Danda, I read the whole thing, I have U-joints to investigate first.

Second on my list is to track down, read, search and diagnose my air intrusion system. I pray for less cursing but won’t guarantee it
 

danda

Registered User
Joined
May 17, 2022
Posts
72
Reaction score
18
Location
CA
Second on my list is to track down, read, search and diagnose my air intrusion system. I pray for less cursing but won’t guarantee it
If you haven't already, I'd suggest installing an electric fuel pump first thing and installing a block-off plate where the old mechanical pump was. This will bring benefits (shorter crank times) even after you've found/fixed the air intrusion issue.

Second, with a flashlight perform a visual inspection of all the fuel lines. From the tank to the fuel pump, fuel pump to filter housing. all ports of filter housing. housing to IP. All the injectors and the (return) hoses between them, and the top of IP back to the tank (as much as you can see). If you see *any* sign of diesel/oil around these connections, that is likely your culprit. Clean, start engine, inspect again.

In my experience you can pretty much figure out if the air intrusion is before or after the IP based on whether the truck a) starts then dies, or b) cranks without starting. If (a) then your leak is probably before IP, and if (b) probably in the return lines after the IP. Others might debate this, but I think its usually true/correct. The reason is that in case (a) the high pressure side stays primed, but in case (b) it is able to bleed off and lose pressure from the IP return and eventually the injector lines.

If you think it is in the return lines, a shortcut is to cut the return line underneath truck, plug it, and then blow compressed air like I did. This could save you a lot of wasted time redoing o-rings etc if the problem is not at the injectors. If no air escapes, everything is good up top and maybe there is an issue with your fuel selector valve.

If the problem is before the IP, well the electric fuel pump might actually solve it if you just let it run for a bit before cranking. One could try the compressed air trick here also.

At the end of the day, if air is coming in, then fuel *must* be going out, somewhere. Find the leak, you've found your problem. In my case, the leak was tiny and at the back of the engine behind turbo and going down the firewall where it was near impossible to see. So yeah, just remember those two tees are back there.
 
Last edited:

danda

Registered User
Joined
May 17, 2022
Posts
72
Reaction score
18
Location
CA
Update: I performed most of the mod as described a couple posts back.

I wasn't yet able to install the tee that joins the injector returns to the main return line from IP. That's because I need a 5/16" by 1/4" tee and nobody local carries them. I thought for sure Ace Hardware would have it, but they don't even stock a 5/16" tee, though they carry both 1/4" and 3/8". amazing. Hard to support local merchants when they won't even stock basic items.

Anyway, I ordered a tee and it'll be here in a day or two.

For now I just put a long hose on the injector return line and ran it into a jug of diesel, submerged.

Engine started right up and runs fine. I didn't even need to bleed any injectors after my shenanigans.

So tomorrow if it cranks right up, I'll be jumping for joy, and if it cranks a long time again, I'll be cursing Ford/Navistar all day long as I go back to the drawing board. fingers crossed.
 

Cant Write

Full Access Member
Joined
Sep 29, 2021
Posts
866
Reaction score
719
Location
Placerville CO
My rig is an E-350 van, so only one 35 gallon tank.

I don’t feel like I have long crank times, and I’ll crank after one cycle of the glow plugs and it will usually start to come to life but quit. 2nd glow and fires right off. I only changed 2 glowplugs, but someone else posted about why smoke in the exhaust when cold start cranking. I have that, but no controller clicking, so I’m thinking I still have a couple weak GP’s.

Fuel filter has been moved to trans cross member and is always plum full when I remove it.

Air intrusion seems to happen when I work the engine hard, climbing both Vail Pass and Loveland Pass (IKE Gauntlet) resulted in a huge smoke show once I created the summit.

Will inspect all lines and report back. In a couple days. I have 2 more shifts.
 

Forum statistics

Threads
91,217
Posts
1,128,479
Members
24,045
Latest member
Ramtough01

Members online

Top