Getting to close to making this motor run, now it is backfiring, thinking a scanner might help diagnose the problem, which scanner is compatible with the 5.7?..Any feed-back is appreciated..
TechMate Pro Scan Tool The older techmate is no longer made
Basic scan tool kit $499.00 (As much as you might or might not use it)
The Diacom (rinda) is a better setup. Depending on engine Manuf it has the repair manual included in the program
As bondo pointed out, we need more info. Over the past 40 years there have been thousands of 5.7 volvo penta models
A few things cause backfiring:
Running lean from either crud in the fuel system, water in the fuel or other
Timming out of adjustment
Ignition cross-talk from either improper plug wiring, bad dizzy cap or other
Visually check the dizzy cap and rotor. If there is any green fuzzy stuff replace them
If you have a crab-cap on your dizzy, change it, dont even think about it, change it as they short out internally
Yes, I bought the boat after sitting for years..I was not able to drain the gas so unfortunatley I was forced to run it through the motor..I have gone through two clean tanks of gas and four filters..Cant imagine it is bad gas at this point..
I have did a tune up which includes New spark Plugs, ignition wires, cap, rotor, impeller. water pump, thermostat, both fuel pumps, fuel filter, knock sensor temp sensors, drive belts oil filter and fresh Synthetic oil.
There is only one Volvo Penta mechanic on this island, he is backed up a few weeks..
As bondo pointed out, we need more info. Over the past 40 years there have been thousands of 5.7 volvo penta models
A few things cause backfiring:
Running lean from either crud in the fuel system, water in the fuel or other
Timming out of adjustment
Ignition cross-talk from either improper plug wiring, bad dizzy cap or other
Visually check the dizzy cap and rotor. If there is any green fuzzy stuff replace them
If you have a crab-cap on your dizzy, change it, dont even think about it, change it as they short out internally
I really appreciate your help, thank you! any links on how to set the timing? I can not find the factory marks to set the timing appears as a $500 scanner is my next step..considering that is equal to a few hours at the Volvo mechanic might be the right a good choice
Not an expert on VP but I'm finding the GSI has mostly the Delco EST distributor. If this is the case then it needs to just be adjusted to stop the backfiring, unless there are other issues.
Start by rechecking the firing order 1-8-4-3-6-5-7-2
1-3-5-7 is on the left (port) bank
2-4-6-8 is on the right bank.
Distributor rotates clockwise looking down from the top
If all that is good and it still backfire during idle and low speeds, need to find out if the timing chain slipped
Not an expert on VP but I'm finding the GSI has mostly the Delco EST distributor. If this is the case then it needs to just be adjusted to stop the backfiring, unless there are other issues.
Start by rechecking the firing order 1-8-4-3-6-5-7-2
1-3-5-7 is on the left (port) bank
2-4-6-8 is on the right bank.
Distributor rotates clockwise looking down from the top
If all that is good and it still backfire during idle and low speeds, need to find out if the timing chain slipped
With all the issues I am working to fix, i often forget to fill in all the blanks in my description of issues..Idle speed no back firing..Only happens when I have been running to motor for a while at high RPMs..I will go back and check to make sure all the plug wires are set correctly..
Once again, I really appreciate the shared knowledge and the high integrity of this site..
The piece mill of the info is making it a bit hard. If you can think of any other info let us know.
Since it idles fine and only starts this after running hard for a while would lead me to the Anti-siphon valve, tank pickup tube, clogged tank vent or gas cap. Sounds like the boat starts starving for fuel and therefore a lean condition starts. The lean condition will cause a backfire.
Anti-siphon valve is on top the fuel take and the rubber fuel line is attached to it. Remove the fuel line and then unscrew the valve. There is a ball and spring inside which can cause a restriction.
The tank pickup tube is inside the tank and fuel is drawn out it thru the anti-siphon valve. If tube can be unscrewed do so and check, otherwise blow some low pressure air thru it.
The next time it starts backfiring, stop the boat and open the gas cap, if you hear air rushing in, the vent or gas cap is clogged
I really appreciate your help, thank you! any links on how to set the timing? I can not find the factory marks to set the timing appears as a $500 scanner is my next step..considering that is equal to a few hours at the Volvo mechanic might be the right a good choice
