supercharged 502 won't get on plane
 

I'm starting to think this supercharger is more problems than benefit. Here's the latest: I bought a 280 Powerquest with a supercharged 502. Minimal hours on the engine and supercharger (Procharger M1).

When first getting her out she ran fine but an alarm kept going off. I couldn't find out the cause of the alarm, but it was determined to be the ignition shutting down because of a failure in the spark driver in the ECM. I had to purchase a new ECM. Big ticket item but she ran great...............for a few hours.

Now, she won't get on plane. With the throttle wide open she spits and sputters, the boost gauge goes into boost and she struggles. All of the suddend.......poof it will kick in and take off. Runs a little rough

Come off plane and it's the same deal all over. Idles fine, no smoke, no change in oil color, oil temp, oil pressure, fuel pressure readings are all normal.

A friend of mine thought it might be a fouled plug, so we changed them all. Didn't make a difference. Now, we're going to try and change wires, and if that doesn't work change the coil.

Now, the common denominator here is this started happening about 10 gallons of fuel into a a new fill up. I had been running either Sunoco 94 or Valero 93 (off of the street). I filled up at a local marina with their no ethanol 91, and 15 gallons later I started having the problem.

Now, I'm thinking maybe bad fuel. Any suggestions are appreciated.

Change the filter/separator.

Yes What He Said Try The Fuel Water Filter.

I agree with the above and also have been told marina fuel is known to have excess water in it.... I was told to stay away from it. Just what I have been told.

if fuel filter does not fix problem try dist. cap.

I had the same problem in my boat. What I had to do was lock the timing at 32, but I have a carb. You might try a v6 ignition so it advances faster.

Thanks for the input. Still struggling. As of now I've: pumped out all of the fuel I thought might be bad. Added 90 gallons of Sunoco 94, added a can of dry gas/injector cleaner (I forgot the name, but my mechanic gave it to me.......good stuff), changed the water separator, changed the plugs, changed the cap and rotar, changed the wiring, put tighter fittings on the vacuum line (from the fuel regulator), tried a different ECM, tried a different MAP sensor. Each change was done one step at a time and taken out for a trial immediately after. UGHHHH, no change.....she still won't get on plane.

To review: starts up great, idles great, no smoke, oil clean, throttle up and she won't get on plane ....starts struggling at about 1500/2000 RPM, goes into boost but doesn't have any power. Once in a while (about once out of every 5 times) something will seem like it catches and she'll take off, get her up to about 2500 RPM and climbing and comes out of boost and runs normal. Runs strong until you back off........and then won't get on plane again.

It's my understanding you can't change any of the ECM settings without the GM software. True? Does that also apply to the timing? Are there issues in the blower I should be checking? HELP !!!!

Please any other suggestions?

Call Tyler Crockett. He has a lot of experience with prochargers and computer programming.

It is of course the EFI out of wack and it may take weeks to hunt it down.

Patri: Actually I had a problem with a alarm going off and couldn't figure out what it was, so I took the boat to Tyler. He is the one who put a new ECM on which took care of the alarm issue (turned out it was the spark driver). So, I thought the new ECM might be the problem. I called Tyler who said it wasn't the ECM and suggested I put the old one back on and see if anything changes. If not, then obviously it's not the ECM. I did that and the problem was the same. Tyler then suggested the Map Sensor, so I switched that. That wasn't it either.

Tyler is a great guy, but I can't get the boat to him, and he's so jammed he can't get to me.