bolin22

Who is the resident 575 expert on here? I have a 2002 29 Fever/575 that I am having trouble figuring out some issues.

F-2 Speedy

iTrader: (6)

Expert ? he got banned........post up the issues you are experiencing

bolin22

I developed an issue last season with startup. cold/hot, didn't matter, when starting it would crank over, a few cylinders would fire, then just crank crank crank.....until i raised the throttle lever to about 20-30% and then it would backfire and stumble to life. I attributed it to possibly a faulty injector(s) after reading numerous posts and talking with Eddie Young. After debating on rebuilding the stock injectors I decided to go with Eddie's injector plate update. After install, cold startup is good, however it seems extremely rich at idle.....now to my current problem.....when coming off of idle, raising the throttle to accelerate, at aprox 1200+- rpm the engine coughs and dies. ( i believe it is a lean cough). After talking with Eddie and pulling codes (21 TPS v high;23 MAT sensor v high;34 MAP V low) we thought the TPS could be the issue, To verify an issue I filmed the throttle blades movement while watching the scan tool and advancing the throttle lever.....sure enough the TPS was not sensing % until I would get to about 15-20% throttle and then it would start counting......replace TPS and MAP sensors....cleared codes....1st time out ran great (still rich at idle) but no lean cough.......I thought great problem solved......2nd time out, long idle through no wake and waiting for oil temp to rise.....go to take off and.......1200 rpm cough and die again.....having to raise throttle again to startup, small backfire and stumble to life again.....3 times in a row.....the 3rd time i raised the throttle to 3000 and let it run for about 45 seconds.....brought back to idle and accelerate without issue.
Once running and on plane the boat has never run better....smooth, max rpm, zero issues once past the "cough"
I did not replace the "MAT" sensor, not sure if that could have any effect on the situation but after clearing the codes and being out several times now none of the original codes have returned
Towards the end of the last test ride we were cruising at 3500 and started advancing the throttle to 4000 and I noticed the alarm going off....quickly shut down, scanned the codes and had a code 43 ESC detects constant knock stored.....cleared the code, started back up (with no issues) and took back off with no lean cough.....alarm stayed off the remainder of the trip.....

SO at this point, I am beyond frustrated on where to go next, I am going to go back to the TPS and see if it is picking up throttle input when I start to move the throttle lever and go from there.....

bolin22

here is a video of the issue (hopefully the link works for you).
https://www.icloud.com/photos/#043X8...1tp1dsiVXBrRHA

F-2 Speedy

iTrader: (6)

Have you done anything with the IAC pulled and cleaned or replaced ?

bolin22

Yes, I replaced the IAC with a factory Merc before I did the Eddie Young upgrade. I believe the original was working as there was no change from old to new.

snapmorgan

iTrader: (2)

Have you checked the distributor cap and rotor? Those GM EST caps and rotors will barely make it a season before corroding up badly.

bolin22

Yes, I have put a new cap and rotor on several times, plugs every 20 hours, replaced the module underneath the cap, wires are about 100 hours, however, I will inspect....again. Not ruling out anything at this point. THX

F-2 Speedy

iTrader: (6)

Have you checked the timing ? stock tune on a stock engine ? Im not sure if Eddies TB mod's require a remap

bolin22

I checked the timing at idle, but I can check it again. Running Eddies' tune for his plate for a stock engine. The lean cough started after installing his plate. Eddie is saying its the same tune he has used on lots of other 575s without issue.