Injector issues

[jfp3205]

Hey everyone,
So here is my problem. I have a 92 F350 7.3 IDI non turbo (I wish I could afford a turbo. I am as slow as granma). The truck cranks and runs fine during the day and when it is started up soon after stopping, it fires on the first couple of cranks.
My problem is when it sits overnight. It cranks and cranks and cranks to the point I am ready to just spray it (I know gary, don't do it) and it finally starts. I sometimes have to do a couple of attempts to not overheat the starter. Once it starts, I kill all the bugs in my yard with the gray/blue smoke that comes out. I am assuming this is unburned fuel.

I was leaning into a possible return line leak but never found anything and someone I know who is(a mechanic) who told me that the system is losing prime overnight and he suspects that one or more injectors are leaking down.

First of all, does this sound possible even if the truck seems to run fine otherwise. No shake, no smoke just not much power in my mind and poor MPG

Second, Is there something I can run with my fuel to help clean the injectors in case it is just carbon or something making the injector not seat all the way closed?

Third, if it is the injectors going bad, I am on a HUGE budget and want to get the best deal for the lowest price. I would love a set of moose injectors but I have to stay stock. Ant suggestions from places like auto zone and what kind is the best value

Thanks

 

[cpdenton]

I don't think this is a problem with the injectors. The fuel system is probably losing its prime. Next time it sits overnight, before cranking, unscrew the fuel filter and see if it is full or not. If it is leaking down, the filter will be a inch or two low most likely. Mine was doing this, leaking air through the fuel heater in the filter head. There are many places on the return line systemthat can have an air leak that causes these symptoms.

 

[gatorman21218]

go to ace hardware and get a couple feet of clear vinyl hose. 5/16 ID. replace the return line from the number 1 injector to the filter head and the line conneccting the IP and the number 2.

that way you can see if its leaking down over night.

IMO you have two problems. Air intrusion and a worn fuel system. Blue smoke means slobbering injectors.

 

[jfp3205]

I only have the smoke on startup in the morning, I se no smoke at all during the day but I do notice a small amount of black soot on my bumper

 

[jfp3205]

is there any way I can test the system to try to isolate where the problem is? does the system have a check valve someplace?

 

[DragRag]

Sounds like your getting air intrusion to me. Return line and olives at hard lines need checking out.

 

[rattleonby]

If you have this cranking/smoking problem only after sitting overnight but starts and runs/drives ok otherwise when warmed up and normal smoke I would check all of your glow plug components for proper operation; i.e. gp module/solenoid, temp sensor ohm specs, and glow plug ohm specs. I dont have the specs of these off the top of my head but im sure many on here do. At what outside temps are you having this problem? Still cooler mornings?

 

[Can30Diesel]

Just echoing whats above. Air intrusion and/or glow plugs.

Easy way to test glow plugs if I remember right is to disconnect the harness connection to them, then grab a test light, put the clamp on the positive batt post and touch the probe end on the spade or bullet connector on the top of the glow plug. If you get light, its ok, if not, its bad. I am sure someone will correct me if I am wrong, its been a while. The other thing to consider is the glow plug controller, they tend to die in both the 6.9's and the 7.3 diesels.

About air intrusion, those 7.3 filter heads are legendary for leaking on the top where the heater and other sensors are. They can be rebuilt pretty inexpensively if I recall right.

 

[Hydro-idi]

We need to know a few things to begin with like stated above. We need to know how old the injection system is on the truck. If it is the stock IP and injectors (gray paint), they may need to be replaced, which will in turn restore lost power you may be experiencing.
Second, how old are the glowplugs? Does your wait to start light come on in the morning? If so, for how long? And does your truck spit out white smoke when cranking engine over? If your engine is smoking while trying to start, your glowplug system is not functioning properly and is in need of service.
Also, does your engine start for a quick second then die? If that is the case, you are experiencing an air intrusion.
Third, are their any fuel leaks around the return lines and/or hard lines?
These are just a few questions that will help us identify your hard starting issue. While you are in there, I would make sure fuel filter has been replaced recently. A clogged one can hurt power and efficient starting. If you are looking for injection system parts, Mel (Agnem) and Russ (typ4) have excellent injection system products. If you are on a budget, try not to buy reman injectors. I have found them to be junk. Ebay sometimes sells new delphi injectors and I have heard dieselogic does a good job at rebuilding db2 injection pumps. Let us know any more questions you may have. There are many great guys on here that will help you out just about any time of the day .

 

[icanfixall]

Your morning hard start is from fuel leaking down. Look at the feed line to the filter. That brass nut has a gasket in it called an olive. They harden and leak. So air gets sucked in as the fuel runs back. Now a good mechanical lift pump has a check valve in it but yours might be shot. The pump is around 25.00 at most auto partsd stores. Look at the filter yo injection pump line. That too has an olive in each end of it. They are 5/16 size but the other olive in the filter inlet is 3/8 size. Any fuel injection shop has them or typ4 or agnem here sells them. Waht does your return line system look like and how old it is makes a big differance. The return line kit may need to be replaced but please tell us how old it is first. As for bad injecters.. I don't think so but their age will tell us if they need to be replaced. Only two sellers of injecters is trusted around here. Thats agnem or typ4. They are truely great members here and will not rip you off like many other ebay sellers will. Just read the Hall of Shame forum to learn about them before wasting money on them... They sell crap and give you the chits doing it...

 

[mblaney]

There is a very simple way to check your glow plugs so you are not shotgunning the problem. Find a clamp-on meter (ammeter) and check the main line to or from your GP solenoid. The peak current should be around 375 - 400 amps (IIRC) and it will drop as the GP come up to temperature. This check will take about 30 seconds to do and then you can focus on fuel issues. Google a Fluke model 36, 365, etc to see what you need. Measuring the actual current draw is much more telling than voltage.

 

[icanfixall]

Thats great information to know about the draw on the system. I need to bench mark that..Thanks....

 

[mariner45]

I would vote for the air intrusion in your case.
Yesterday I started my 86F250 for the first time in about ten months. It took a little bit of starting (several turnsof the engine) but fired up on the first attempt at starting. Ran it for about 30 mins or so and then shut it down. Went to start it today primarily to check alternator charging voltage (14.55 is what I am getting at fast idle) and had a bit of a miss. Thought nothing of it and left it run again for several minutes. On checking back I could smell diesel fuel leaking from somewhere. When I looked I found the fuel reurn line from the passenger side front injector (#! ? ) to the fuel filter (3 way fitting) was leaking fuel. The line wasn't more than a couple of years old, but was dry and cracked. Replaced it with new USA made fuel line and all is well. Boy, did the engine sound change after fixing the air leak !!! I must have had the leak for a while and didn't realize it - I thought that maybe my injectors/ injection pump might need changing. Turns out so far, that the injecors and fuel pump are fine - just air getting into the system.
So, the point here is go ahead and renew all of your fuel return lines with new USA made fuel hose (3/16" inside dia. is what I used). Then you will know for sure that the fuel return hose system is good and it will be cheap to do at around $35 - $40 for parts.
HTH
mariner