Hey guys. I posted this in the E-van forum, but one of them recommended I post here, as well. So here's the issue:
I have a 2004 E350 V10 with 240k miles on it. I had a terrible miss, which became multiple cylinder misfires. I just replaced all 10 spark plugs with Motorcraft SP-479's, and all 10 COP's with cheapos from eBay (yes, I know the gamble there. Used them on my F150 and had great success, so I tried again with the van). Turns out 3 of the new cheapos were bad, so I put the original Motorcraft COP's back in those 3 spots. So no misses and no CEL now. However, my gas mileage is horrendous. Even worse than when I had all the misfires. Any ideas what could be going on?
I have never worked on a V10 on a van but the first thing I would do is check all the vacuum lines and the hose and fittings that come left valve cover to the air inlet tube not the PCV valve, the side may be different on a van. That tube is after the MAF sensor it can throw things off if it's sucking air.
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I think your van has the same air box as the F-series. Check the rubber plug on the bottom of the MAF housing where the wires go through. If that's not in place, it'll allow a small amount of air to get past the MAF causing the engine to run lean.
I know, LEAN makes it use more gas? Yes - because of the lack of power, you need to lean into the gas pedal more, causing more air (and fuel) to enter the engine. But still lean, so lack of power, and yet, more gas overall.
Same theory applies to any other vacuum leak.
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Hey, so this is a super late response, but I haven't really been driving much my van lately. I did use it this weekend, and after checking all the hoses and fittings, everything seems on tight, but bad gas mileage still remains. That said, I am smelling gas while the van is running. I've taken the dog house back off, as well as looked through the hood, and I can't SEE any gas, but I can certainly smell it. Any idea what I should be looking for, or what I should check first in trying to diagnose this?
Hi there. Unfortunately my lack of timely posting does not mean I've fixed the problem.
Under normal conditions, I was able to get between 350-390 miles to a full tank of gas. Mostly highway driving, but some city. In its current state, I get about 250 miles to a full tank of gas. Literally at least 100 miles difference. And it still smells like gas in the cab every time I crank the van.
Got any ideas?
Is it possible I don't have a spark plug seated correctly or something? I mean, it's not running poorly. No misses, and CEL. It's just eating gas like crazy, and smelling like gas.
Sorry again for my late response on this and bringing up old threads. My problems just haven't been solved yet, and it's been to freaking cold to go outside and try to fix things.
Fordboy, I did try cleaning the MAF. It did not seem to help.
Bently, I don't have any CEL codes or anything. I, too, like to use OEM products. My budget, however, doesn't allow for such things. I also changed the fuel filter probably 30k miles or so ago.
Because of the rather strong gas smell, it was brought up to me that I must have a leak, as I shouldn't be able to smell gas with the engine running. I was told to check for a leaky fuel injector. I don't have a bad enough leak that anything is hitting the ground underneath the van, but when looking at the injectors, all of them are bone dry except number 1. It has a little pool of what I assume is gas inside the lip at the top of the injector. Could that be my issue?!
I do not have experience at replacing an injector. I've seen there a several videos on youtube and such on how to do it. However, I'm not sure what to expect when lifting the fuel rail. Is it difficult to get off? What steps do I need to do besides removing the bolts and disconnecting the fuel lines (the lines, of which I don't know the location)?
Thanks for your help and ideas on this so far and moving forward.
Okay I did a bunch of research last night, and I'm far less worried about removing the fuel rail than I was yesterday. Here's my next question.
If I have a leaking fuel injector, is it just the O-ring that is failing, or do I need to replace the entire injector? The van seems to be running fine. I don't have a miss. Clearly, that's a large price difference in parts, and I don't want to spend $100 for an injector when I could fix the problem by spending about $8 for O-rings.
Did you removed the fuel rail when you changed out the coils? If you didn't, I wouldn't expect that something went bad during the coil/plug change. There are four bolts, two on the sides of the intake manifold. There is also one on the back of the intake manifold. (should be the same as my f250) The one on the back of the manifold should be easy to access from the doghouse.
You should be able to inspect the O ring and determine if it is good or bad. Is it split, torn, etc?
Have you scanned the engine for codes? You should see if there are any "pending" codes. Pending codes will not make the CEL light go on.
You could try to just turn the key forward to the run position a few times to pressurize the system. Then sniff around. That way the engine is not running. You may need to re pressurize it a few times.
Otherwise the should be a valve on the passenger side of the fuel rail. Borrow/rent a fuel pressure gauge. Hook it up to the valve, and pressurize the system. It shouldn't fall. Yours probably will, but how fast? That will give you an idea of how bad it is.
Do you sniff the exhaust? Notice any difference? Did you plug your idle air control valve back in? It is just behind the throttle body.
Lots of ideas for you.... I am still a little new to the v10. But, no stranger to motors. I just pulled the top half of the v10 apart to find a coolant leak. I replaced all the same items you did while it was apart.
I dont think the Autozone/ oreilly scanners will show pending codes. However the local dealership can do a diagnostic check for you. Of course there is a fee. I would call and check around the area. Unless you know someone with auto engenuity or a snap on scanner that is able to show live data.
99 F250 CCSB V10 Lots of money into it.
This might be the slowest repair I've ever attempted...
So I was digging in to this today to try and repair this injector issue, and I think I may have found a bigger problem. Would these pics be an indication of a cracked fuel rail? It is definitely wet to the touch, and smells like gas, but I can't see gas coming out of there when I turn the key on. I can, however see it running down the injector.
None of the other injector spots look like this. Also, the connector that goes into the injector (not pictured) is totally discolored and basically black. None of the other connectors look like this.
If it is a cracked a fuel rail, is it just as straight forward as removing this one and replacing it with a new one? After a quick Google and Rock Auto search, I can't seem to find a fuel rail. Am I just calling it the wrong thing?
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