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GRUNION
04-26-2006, 08:20 PM
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I need some help. First off I have a EFI 502 with a pro charger. a few weeks ago I started loosing rpm. Now I can only get about 3000 rpm and it runs like its missing. and I think its pinging but not sure Im not a big motor guy. I have done a compression test everything is good I have replaced the cap rotor and plugs, Because we thought maybe it was fouling plugs I also took my computer over to az speed and marine to turn my cold start off. I was told to do this by Jim and a friend of mine Charley because with the pro charger it runs rich until it warms to 160. and with the procharger you dont run a thermostat so u never get to 160. also I found the vacum hose broke from the fuel pressure regulator to the manifold and I fixed that. today we ran the boat and it was the same 3000 rpm. We are thinking it might be a fuel pressure problem I have an aeromotive fuel pump and it sounds awfull. I was told you should barley hear them. tomorow morning we will check it when we get to the shop. But I was wondering if you guys have any other ideas. Or have had this problem

andy01
04-26-2006, 09:16 PM
Check the power to the fuel pump as well, make sure the boat is charging 100 percent. A voltage problem can be a big problem for a high output pump. Or pumps will sometimes get louder if they have something keeping them from getting the flow they should. Clogged filters and such.
Andy

BadKachina
04-26-2006, 09:38 PM
Is it missing all the time? Those GM distributers are prone to wearing out the bushing, wich will in turn let your timing move around. You can put a timing light on your motor and see if it is moving. The vacuum line off on your regulator will just keep you at full pressure all the time instead of backing off while at idle. Should have no effect on top end. Check your pressure off the injector rail. Not sure what pump you have or what your regulator is calling for pressure wise, if it's a Procharger set up give them a call and find out what pressure you need. Could just be an ecu problem and it could be an injector problem as well. Lots to check, just start somewhere and keep going through stuff. You wouldn't have the first GM injector to fail and you wouldn't have the first ecu to go bad.
I have a hp aeromotive pump in stock if you need one, I think it's part number 11110 or 11108, but I'm leaving for LHC in the evening. If you need it and can't find another one call me in the morning.

upsman105
04-26-2006, 09:47 PM
I saw your boat go out on Sun. you must have finally got it all back together.

BadKachina
04-26-2006, 09:56 PM
I saw your boat go out on Sun. you must have finally got it all back together.
Pretty much, I'll finish it tommorrow for the Poker Run. I had it out Friday and blew the drive, rebuilt it Sat morning so I could try again Sunday. It's making really good power, if I could just get the drives to stay together....... I really need to ponie up and get a B-Max. Sunday I took it easy on it, had it up to 4500 rpm @ 72 mph, didn't want to get it any higher with only a couple of hours of hose time on it.

upsman105
04-26-2006, 09:58 PM
cool....looked pretty good I was coming back from COP, no one wanted to go to the lake, so I took my bike out.

BadKachina
04-26-2006, 10:01 PM
I was pretty windy, but I was Jones'n and I wanted to make sure all my gauges worked and check for leaks, etc., before Havasu.

upsman105
04-26-2006, 10:11 PM
Sounds like everything worked??? And if you blow the drive again, that is why you keep the spare in the shop. :)

BadKachina
04-26-2006, 10:16 PM
I'll have an extra in the back of the truck this weekend........ :)

upsman105
04-26-2006, 10:18 PM
With any luck that is where it will stay..

GRUNION
04-27-2006, 06:17 AM
Is it missing all the time? Those GM distributers are prone to wearing out the bushing, wich will in turn let your timing move around. You can put a timing light on your motor and see if it is moving. The vacuum line off on your regulator will just keep you at full pressure all the time instead of backing off while at idle. Should have no effect on top end. Check your pressure off the injector rail. Not sure what pump you have or what your regulator is calling for pressure wise, if it's a Procharger set up give them a call and find out what pressure you need. Could just be an ecu problem and it could be an injector problem as well. Lots to check, just start somewhere and keep going through stuff. You wouldn't have the first GM injector to fail and you wouldn't have the first ecu to go bad.
I have a hp aeromotive pump in stock if you need one, I think it's part number 11110 or 11108, but I'm leaving for LHC in the evening. If you need it and can't find another one call me in the morning.
Thanks I will call you if I find out its the fuel pump. Where are you located. My shop is on bell and I 17 hope your close. hope i can figure this out early so I can take it to havasu tomorow.

BadKachina
04-27-2006, 06:33 AM
Northern and the 101. That dually is bitchin in your sig........

Mrs. Grunion
04-27-2006, 07:40 AM
Northern and the 101. That dually is bitchin in your sig........
Thanks

GRUNION
04-27-2006, 07:41 AM
Thanks
Oops was on the wifes computer. lol

GRUNION
04-30-2006, 02:14 PM
OK first off thanks for the help. I wasnt able to fix it before the poker run but we went in a friends boat.
Second we found a few things out. My fuel pump wass good but my pressure was at 66 way to high it should be 44. I was also missing a knock sensor on my boat so I put one on why anyone would take that off is beyond me. Then with a couple people we were able to track down the noise in my engine it was the timing chain or so we thought. You could actualy feel it hitting the cover. So we pulled the cover and found it had a half inch of play. So we replaced it and put it back together. not bad for half a day huh. Fire it back up and same noise .... So now im thinking I lost a lobe on a cam or a lifter is not flat. and forceing the cam forward. And now Im gonna have to redo all the work we did. At least the pulling everything apart stuff ,what a pain. I think I will have also ate up the distributor gear from the cam moving forward and back.....
Does anyone think I should run anything different than a stock cam? Remeber its a 502 with a procharger and lightning headers

GRUNION
05-01-2006, 08:46 AM
And can I get more hp out of a cam?

GRUNION
05-02-2006, 09:02 AM
ttt