DowneyB
Professional
I have a 7.3 that kinda "popped" one morning when I started it to leave for work, and its had a very subtle miss since then. I've had this motor for years and it is kinda worn out but its always ran without a hiccup until now. It does use a fair amount of oil.
The miss is almost imperceptible at idle, it is most obvious when loading it at around 2000 - 2500 rpm, and it usually misses but occasionally it will run smooth for a few revolutions. At idle it will occasionally shoot a hard fire out of the exhaust. Oh it has started producing this very visible white haze/smoke when idling cold. The haze almost disappears when warmed up but it is still there. I'm sure the neighbors love the diagnostic sessions I've had lately.
I took the valve covers off and could find nothing loose or out of place. I ran it without them and everything moved like it should with no odd noises or escaping gasses.
I just did a compression test last night, all cylinders measured right around 280 psi except #7, which came in at 190 consistently. I'm pretty sure the adapter I had did not seat/seal in the glow plug hole, but otherwise it worked okay. The #5 glow plug was wet/oily when I took it out. I did idle the truck for a few minutes so that the engine wasn't stone cold for the compression test. It does smoke a bit if you take the oil cap off while running.
This is not a truck I have spent a lot of money on, mostly because I can't afford to spend a lot on it. I've had the motor for almost 20 years, it was in my first truck and then sat for most of the last 5 years until last January. I put a used IP on it a long time ago, but I have never touched the injectors. I have an electric fuel pump on it, and I have to keep cleaning the rust flakes out of the prefilter or the pump will start sucking air from a fitting somewhere.
Does this sound like an injector could be causing this? It will be a bit until I can afford a set but I also don't want to throw money at it if I don't have to. Is there something obvious that I should check for or might be missing? I ran a filter full of ATF through it, but it didn't seem to help much. I haven't really driven it since then as I don't know if it will do more damage or not.
The miss is almost imperceptible at idle, it is most obvious when loading it at around 2000 - 2500 rpm, and it usually misses but occasionally it will run smooth for a few revolutions. At idle it will occasionally shoot a hard fire out of the exhaust. Oh it has started producing this very visible white haze/smoke when idling cold. The haze almost disappears when warmed up but it is still there. I'm sure the neighbors love the diagnostic sessions I've had lately.
I took the valve covers off and could find nothing loose or out of place. I ran it without them and everything moved like it should with no odd noises or escaping gasses.
I just did a compression test last night, all cylinders measured right around 280 psi except #7, which came in at 190 consistently. I'm pretty sure the adapter I had did not seat/seal in the glow plug hole, but otherwise it worked okay. The #5 glow plug was wet/oily when I took it out. I did idle the truck for a few minutes so that the engine wasn't stone cold for the compression test. It does smoke a bit if you take the oil cap off while running.
This is not a truck I have spent a lot of money on, mostly because I can't afford to spend a lot on it. I've had the motor for almost 20 years, it was in my first truck and then sat for most of the last 5 years until last January. I put a used IP on it a long time ago, but I have never touched the injectors. I have an electric fuel pump on it, and I have to keep cleaning the rust flakes out of the prefilter or the pump will start sucking air from a fitting somewhere.
Does this sound like an injector could be causing this? It will be a bit until I can afford a set but I also don't want to throw money at it if I don't have to. Is there something obvious that I should check for or might be missing? I ran a filter full of ATF through it, but it didn't seem to help much. I haven't really driven it since then as I don't know if it will do more damage or not.