The fuel pressure regulator on that model should be located in the housing that holds the fuel pump. In a v-drive it will face forward and is held by one screw. It looks like this http://www.bakesonline.com/detail.aspx?ID=1650
Heres a couple threads I read last fall to help me Jarod.
https://forum.supraboats.com/showthr...lt-cutting-out
http://www.wakeworld.com/MB/Discus/m...tml?1240182472
It's supposed to snow in TX next week so I guess I wont be testing anytime soon, but my list of possibilities is
1. Fuel pump and or trash in fuel lines
2. Fuel pressure regulator
3. Limp mode due to oil pressure sensor or similar sensor, hopefully the engine is throwing a code if this is the problem
3. Limp mode due to overheating, I checked impeller but Ill go ahead and replace it and try to clean out the raw water heat exchanger thing
Thanks Travis. That's some good info! I will have to check out the heat exchanger too and see if it's clogged. That happened on a friend's Tige. Then it's' servicing the trailer, 2nd battery, LEDs, and swim platform pad next. Quite a few projects before the first outing!
One thing I had to replace when I had rough idling/sputtering engine issues was I replaced the TPS or Throttle Position Sensor. I actually picked one up at Oreilly's for a 1991 K1500 Chevy Blazer and it fixed all my issues. I have seen a lot of other threads that say the same thing. The TPS on the Assault Engines go bad around the same times on the same year models. (I figure it's because most sit through the winter season. Here was some recent info I posted about the TPS:
If you take the TPS off it is spring loaded. When I turned my old one with a screw driver it would stick on the idle side of the spring action. replaced mine and she runs good as new. Nice and easy idle at 800 RPM's. Just make sure that when you put the new one on turn the TPS to the left (or towards the front of the boat counterclockwise) to get it onto the small keyed shaft and then turn the TPS to the right to line up the bolt holes (This will load the spring tension). My throttle body had a small plate under it and I simply bent it down to get the TPS on and then bent it back up to flat gently. Very quick, easy and cheap fix. I got my part from Oreilly's and used one off a 1991 K1500 Chevy Blazer. I have the 5.7 Indmar Assault. Hope this helps you out!
Thanks supraaddict, I thought the tps would be harder to change so Ill probably throw a new one on also. Was your problem constant or only after you've been on the water for a few hours?
I just picked one up at O'Reilly's yesterday and hope to put it on this weekend. It was $40 with the lifetime warranty...$36 without. The issue I had/have (don't know if it's fixed since I haven't had it out since I pulled the fuel tank) was only after being out for a little while. I could go out and ride for a while then go sit at a sandbar and it would fire back up. After about 10mins it would start to bog down on me. Last time it happened I was running pretty low on gas and it happened just as I hit another boat's wake. Pulled the tank and found some plastic in there that probably came from when they drilled the original holes. I'm now waiting on a dealer to find a replacement pickup tube and fittings since mine was stripped as I pulled it out.
Mine was all over the place. When it finally went all the way bad it spit and sputtered all the time and even puffed a little blue smoke because it was running so rough. New TPS and she drops down to about 750 RPM's as soon as you let off the throttle. Purrs like a kitten now! Hope this helps you out!
Same with Supraaddict.
Symptom was high idle coming off plane (1800 +), tap the throttle in neutral would bring down the idle to where it was supposed to be.
Then it wouldn't go under load, just back fire and sputter, unless real easy/smooth on the throttle. Belching black smoke for flooding.
Replaced TPS and good as ever with our symptoms.
2004 Supra Launch 22 SSV
5.7L Indmar Assault
"One More Hour"
Might be a dumb question, but is your 5.7 EFI? I am having similar issues with mine and I have the 325 EFI Assault