4.6 losing power around 4K rpm's at the end of a race in the heat

Not getting any replies on this in the CMC forum. I raced with several of you at the 2011 Summer Shootout so hope you're all cool with me picking your brains about this. I'm stumped and few others I've hit up are as well.

My car: 98 Mustang with 4.6 SOHC with PI heads.

At the end of both races last Saturday and Sunday (about 95 degree ambient temp and crazy humidity), my engine would basically lose power / sputter, in 3rd gear around 4500 rpm's late in both races (about the 30 minute mark). Oil pressure was good (about 50) and water temp was about 210 - 215.

Did not happen either day during warm up or qual (stayed out for the full 20 minutes every time), nor early or mid way through the races. Only at the end of each race after being out there for 30 minutes (and later in the day - higher ambient temp then warm up and qual). Other than that, the engine ran very well all weekend.

Am racing again next weekend (July 14th & 15th) and want to know if all the above could have literally been because of the heat.

If not, any suggestions on what to check and/or change ? Fuel Filter ? Fuel Pump?

Thanks

Greg
CMC #36 MW region
98 Mustang

Do the 4.6's have ignition control modules?

do you have dumped exhaust in front of the fuel tank? I've seen the fuel pumps get hot and start shutting down, but they usually just shut off. Other option is 215 water temp it's going to start pulling timing. coil packs will also break down and that would be where my money would be.

Regarding the "ignition control modules".... No clue. How do I find out?

Greg Hampton
CMC #36
98 Mustang 4.6

Quote:

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Originally Posted by rpoz27

do you have dumped exhaust in front of the fuel tank? I've seen the fuel pumps get hot and start shutting down, but they usually just shut off. Other option is 215 water temp it's going to start pulling timing. coil packs will also break down and that would be where my money would be.

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Yep, my exhaust dumps right in front of my fuel tank and yeah, the water temp seemed a little high. But it was about 98 without a 800% humidity.. well. you get the point.
So any fixes and/or approaches to addressing that ? Or .. just part of the deal with that kind of ambient temp ?

try googling "testing 1998 mustang coil packs" and see what you get. Or, just replace them. I know Frank Robertson had some bad ones back in 2007 or 2008? sounds just like your problem.

Roger that. I'll check all this stuff out.

Thanks guys.

CMC #36 MW region
98 Mustang

Yea, test the coil packs and put a fuel pressure gage on the fuel rail. If thats ok check the water temp sender for the computer, its different than the gage sender. Good luck. FMR

Thanks