I purchased a diablo chip this week and I was wondering if I need to change my spark plugs? The chip will go in a 1998 F-250 LD 5.4 auto. has aprox 12,000 miles on the new plugs. They are moter craft copper core plugs.

 

It seems that the mufflers and tires only gets replys???????

 

I don't think that diablo chips are the most popular chips around here. I think you have to change the thermostat but I've not heard that you change the plugs.

 

You should do a complete tune up before you do any mod. Also I am not a fan of the chips there is just alot of hipe around here.

 

i would think you are good to go. the only thing you have to do with a chip is install it correctly and put in higher octane gas.
i ran around 7 months on original plugs at 55000 miles with a supercharger and when i pulled the plugs they looked great.

 

thanks! I just want to do it the right way. The information that I read is from people that have all completed the chip instillation and this will make it easier to do.

 

Hi samkirk1,

Actually, just as a quick comment regarding suvdrvrs response, it doesn't matter what type of chip you use, that isn't going to affect the responses you get around here to the type of question you asked - we all try to help each other. In my case, I've been quite busy & have not had the time to get to every post each day like I normally do for a few days now................also, suvdrvr made an important point about the thermostat - now you're OK, as with the DiabloSport chip you do *not* have to change your factory thermostat like you do with some other chips - Hypertech, for example - you don't need to worry about that, you can continue to use the stock factory 194 degree t-stat. If you *want* to change it, whatever you do, don't use anything colder than a 180 degree unit - I'd recommend just leaving it stock.

BrotherDave (as usual) is correct, you don't need to change your plugs heat range, just use the same heat range as stock and that will be just fine. I wouldn't let those straight copper plugs stay in there any longer than 20K-25K miles before replacement - maybe 30K miles at most. I also say not more than 30K for the factory double platinum plugs Ford says to use for 100K miles - I wouldn't let any plugs (aside from perhaps a Bosch +4) stay in any motor longer than 30K miles, simply because at 30K miles with a conventional single-electrode plug you've usually lost about 6 HP or so to plug wear - this is offset by the normal loosening up of a new motor in a new vehicle, so net power stays about the same or can go up a bit even, but by and large, at about 30K miles you're all thru with the best part of the plug's performance - and I'm a nut for having the best ignition including plugs.

One thing I *would* do is go ahead and change the fuel filter - now that you'll be using premium gas due to the chip, it's a good idea to put a fresh fuel filter on, and then change them at not more than 15K mile intervals with a normally aspirated (non-supercharged) engine - not the factory 30K mile replacement interval, that's too long.

Speaking about your ignition again for a second, in that 1998 5.4 motor you would see better performance and fuel mileage with a fresh set of coil packs - those COP systems coil packs lose output over time - they're subjected to an awful lot of heat, and by now if they are original, they're 5+ years old. Replacing them will give you an immediate noticeable improvement in idle quality, for example - as well as improve power and fuel mileage. Now I know that is very expensive to do, as Ford has unfortunately taken them from being a $25 part to being a $70 part, so a set of 8 can be pricey - thus most people don't replace them until a unit actually fails, or unless they're a drag racer, etc. - just a tip FYI..........

At any rate, you don't really need to do anything to your vehicle aside from normal maintenance to use a performance chip - along with premium gas. I would put a fresh fuel filter on there, but that aside you should be fine since the plugs are fresh.

Have fun & enjoy your chip!

 

Thank you for the reply , and also the magnaflow figh-flow catalytic converters that i orderd and recived." lesson learnt"

 

You're more than welcome & have a great Thanksgiving!