Quick question after replacing my hpop my icp cleaning my ipr and installing blue spring kit in fuel pressure sending unit I believe I've noticed that at start up when engine is cold it lags from take off really bad like to the point where i fear of on coming traffic hitting me while crossing the street however after it kicks into second gear it speeds up and is fine until I stop again then the problem goes completely away when its at normal operating temp is this normal diesel behavior or do i have another problem

Things to note:
Truck has 92k miles with no mods
I'm still only getting 10.1 mpg
I did kind of crimp a fuel line but not bad
35"tires
Rotella t5 15w-40 less than 200miles ago
Ford oil filter and fuel filters less than 200 miles ago
I live in orange county California coldest it gets here is in the high 50's at night and thats not always
No CEL
New batteries less than 200miles ago
Didn't re-learn any computers after new batteries however they were installed one at a time

Thanks guys ill be happy to supply any other info if needed

 

My 03 can be a turd when cold, I never worried about it. Take it easy below 190, I have read hammering on it cold can increase head gasket failure odds. Getting a bigger exhaust will help that out.

When calculating mileage, are you compensating for the tire size? If not, whatever the trip odometer says, multiply by 1.09. This is the correction factor between 265s and 315s, as in your speedo/odometer is 9% slow. You may find that your mileage is higher than you think. Here's an example:
252.5 miles and a 25 gallon fill up (no you don't have to go till you could see the fuel, I'll get back to that). Anyway, that comes out to 10.1 mpg. However, when you use the correction factor you actually traveled 275.3 miles/25gallons=11.012. Not Earth shattering, but it is closer to what the actual number would be.

I did that "go till you see fuel" method for 3 tanks, I was only off about .5~.75 mpg, at nearly $100, I can do without the extra 5 gallons unless its roadtrip time.

What's you altitude there in the OC? I get about 15 when in Phx at 1500ft, only get 13~14 here at 4000ft. Programmers and modules haven't helped my mileage either.

 

Is it a true 35" tire, or something else? I see people often refer to 315/70/17's as 35's and they're not, they're closer to a 34" tire. 34.36" is what the math gives you. Either way, you should be accounting for the larger tires, your mileage is better than you're thinking. It might not hurt to try the fill it til you see fuel method either. 10.1mpg is not normal though. Have you tested the FICM at all?

 

Haven't checked the ficm yet im terrible with a volt meter especially since the one i have has so many different settings I haven't a clue on how to use it

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And ya they are true 35s. 35/12.5/20

 

Break out a tape measure, you'll be surprised. The 39.5/15.50 Boggers on my friend's mud truck aren't 39.5 tall. Regardless, divide the hieght of your tire by 31.5 (diameter of the OEM 265/65/16s) and you wil get your correction. If in doubt, measure the circumfirence with a piece of chalk and roll out one rotation. You can play with tire height using psi, but you can't change a tires circumference. The circ of a 31.5 is 98.96, trust me, the correction factor always comes out the same whether you use diameter or circumference.

 

test that FICM, its easy. when mine started to screw up it would only act funny when it was cold.

 

How long would you say it typically takes to check the ficm?

 

less than 15 minutes and that includes drinking a beer. You will need an extra set of hands for it. Just put the multi-meter in a "voltage" setting, typically shown as a "V" on the meter, there are typically a few different V settings, and they are just different ranges to read from. I think mine has like a 200V setting. On the screen it should show 00.0 when you set it there. It's pretty simple. A weak FICM is notorious for poor fuel economy. When you first turn the key in the morning, can you hear the injectors buzz under the hood? How does it sound? Is it a nice uniform sound, or does it sound like it's "missing"?

 

I did it for the first time - the test itself was real quick and easy (once I got a meter that worked ).

The biggest time consumer for me was moving the degas (overflow) container. That was a sob to move and I ended up popping a hose off.

 

I swapped a FICM on my truck last night in the dark at about 11:30pm in about 8 minutes flat... I'm getting good at it now haha.