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I'm still finding that the truck struggles to pull past 4500 in second and third gear.
I'm wondering if it could be a fuel issue. Not really sure if over the years the pump loses it ability to keep up the pressure.
Since I have to replace the tank, should I just go ahead and replace the pump also? Maybe change out the fuel injectors also?
the truck has 140,000 miles on it.
Check the cat. It might be melted.
brand new cat 2 months ago
+1 noah. the cat is not hard to get off unless the bolts are extremely rusted out, in that case just use a torch.
about the fuel pump, if you can afford the going price witch is around 89-120 depending on who you get the pump from than get it. keep the original just in case. dont go with an ebay pump. i would only go with Delphi, Bosch, and Denso. when you reconnect the fuel lines to the pump make sure that they seal correctly before putting it completely back together.
replace your fuel filter if you haven't already. fuel injectors should be fine. i know 3 mighty max trucks in my area that are between 350,000 - 520,000 miles that are mostly stock. usually injectors dont have issues but it would not hurt to check them out. if you do go and get a set of injectors make sure they are flow tested a 1% within one another and are not rebuilds. you cant rebuild the internals of an injector, just the caps and screens usually.
Brand new Cat, Brand new fuel filter, brand new O2 sensor, brand new MAF........ It pulls to about 4400 then lugs it way up
The reason I think it might be fuel was like in my old 400 hp drag car it would do the same on a mechanical pump, Fall on it's face when the revs got up there but one I put in an electric race pump it would pull like crazy.
I assume these engines should be able to pull to 5500 easy... heck the tach has a 6000 redline.
ya, it sounds like the pump might be getting weak. to bad theirs no easy way to check fuel pressure. in your case i would pull the fuel rail and check to see if its all gonked up. i assume that you have checked the ecm? is this the case in all gear, even 1st and 2nd?
It only seems to be in 2nd and 3rd. I'm assuming with a 3.91 gear it will easily pull but as the ratios decrease it will take more fuel to pull.
I haven't had the ecu out yet.. that is in the plans. I know it has a junkyard ecu on it and the maf was from another dsm product.
I can say it run a thousand times better than it did when I got it in July.
I'm debating a reman ecm or buying a spare one and send it to a reputable shop for the cap repair.
I have been looking for an eprom ecu so that I. Can tune the engine.
I have the correct maf in the truck now..the fuel filter was original before I changed it..the 02 change really helped it from running fat.
I even had the adjust the kickdown as it was shifting at 2000 under full throttle and now it shifts at 5000 under full throttle.