Thunderbolt V Without Knock Sensor Basic Mode

[jsferra1]

I have two issue that I know of ( and hope only two ).

I have a 1997 5.7L Thunderbolt V Without the Knock Sensor,one issue is my Tach is NOT working I will start looking in to that this week/end the other Issue I have and it may be connected to the tach is Prior to setting the timing I put it in basic mode (ground the Pur/Wht wire next to the carb like the book said) set the RPM using my had tach, and set th etiming using an Adv timing light and mirror ( you can NOT see the mark with out the mirror ) and having to use the mirror and timing light at the same time while just about standing on your head is no fun. But I get it set the best I can any way. Then turn it off pull the jumper off the Pur/Wht wire and start it back up and there is no change in RPMs at all. So now I wonder if there is something else wrong or the RPM's should stay the same in which case why would I need to jump the wire if nothing changes.


I have changed the Spark plugs, Cap, wires, filter at the carb and the water/filter , bellows, trim sender, trim limit swt, U-Joints, Impeller, shift cable, cleaned the carb, Gimbal bearing and I still have not even taken it out for more then a quick test two times.

 

[John_S]

Re: Thunderbolt V Without Knock Sensor Basic Mode

I have the same engine. When back in regular mode, I only see minor changes, mostly watching the timing and not the rpms. I have seen some flaky behavior when the battery is toward the low side of the charge. Watch the timing in both modes, and also rev the engine to 2k, and see that advance is working.

I have easy access and viewing (removable doghouse), but a white painted line at the 10BTDC mark on the damper, makes it easier to read during the strobe.

 

[jsferra1]

Re: Thunderbolt V Without Knock Sensor Basic Mode

I have easy access and viewing (removable doghouse), but a white painted line at the 10BTDC mark on the damper, makes it easier to read during the strobe.

Wow , I don't have the dog house on mine, and I don't have the same timing mark as you in fact all I have is a V on the timing cover and that is behind the water pump and is hard to see with out the mirror .

 

[John_S]

Re: Thunderbolt V Without Knock Sensor Basic Mode

The V is the composite style timing covers, and that is what I have. You should have multiple lines on the harmonic balancer for timing marks. If you only have one for TDC, recommend buying a timing tape for your diameter balencer. Using the advance on the timing light is probably OK, but I'd rather rely on actual timing marks.

BTW, that "L" serial number means you have a Gen II drive.

 

[jsferra1]

Re: Thunderbolt V Without Knock Sensor Basic Mode

Thanks for the info,


I know I still have an issue some where since the tach is not working and I get a ping at higher RPMs I was thinking that it all has to do with each other.


The adv timing light works good and should be easy to double check the adv of the timing when I get to that check.

The timing mark tap would not even stick to it it' a mess. I got the boat as a project boat and is almost done with the big stuff, and would love to get it running good so I can start om the small things.

 

[John_S]

Re: Thunderbolt V Without Knock Sensor Basic Mode

Thanks for the info,
I know I still have an issue some where since the tach is not working and I get a ping at higher RPMs I was thinking that it all has to do with each other.

Yes, tach is seperate issue.

Ping, could lead to serious problems and could be inaccurate timing, among other things. Check that advance timing and try retarding base timing it a couple of degrees. Has this project boat sat a long time with the same gas?

 

[jsferra1]

Re: Thunderbolt V Without Knock Sensor Basic Mode

I did check the timimng a couple of times, I'm thinking it could be the gas supply, the gas is fresh. I'm thinking it could be the pump or the line from the tank but this week end I try to test the pump and lines and go from there.