Newbie
06-07-2005, 10:01 AM
Help!!
I've had the car out 5 times this year and had mechanical issues on 4 of them. Three times the engine began popping at about 6000 rpm and would not go past 6K under load. I'm not sure if it's afterburn or limp mode or whatever. Of course, it is an intermittent problem so I really can't tell if I fixed it until it happens at the next event. Last race, I went through practice and qualifying...worked great as long as I kept the exhaust gas temps below 1600 (I thought I diagnosed it). The green came out at the exact time the gremlin did!
I even took it to a dyno to see if I could make it happen..no luck.
So far, I've checked the resistance on the coils, crank angle sensor, checked all the grounds, put in new plugs, got "real" gas (no ethanol added), used better 2 cycle oil. New plug wires too. Changed fuel filter (but the pressure gauge was always fine), added "heat" to the fuel incase there was any water.
I do have one of the lines from the OMP that broke and will replace that today. Also, I've got a gasket problem (mating surfaces need rework)on top of the water pump housing that will be corrected today as well. As a result, I did have a little water and oil spraying around the engine compartment, but nothing drastic. Could that cause an intermittent problem?
I noticed that the trailing plugs look a bit wet and dark where the lead plugs are more brown and dry. I purchased two brand new trailing coils which I'll install today as well. At the dyno, the air/fuel mixture was good, but then again, the car worked well with a bunch of mechanics standing over it.
I have a '87 13-B S4 motor, fuel injected, non turbo built by speedsource. All pollution control has been taked off.
Can anybody give me any ideas on what to look for. The ground on the tach??? Are the auxiliary ports not opening (sometimes). My only repair manual (Haynes) says the port solenoids are driven by air from the air pump, which has been removed. I'm getting frustrated. It should not be this hard.
Your advice is greatly appreciated.
Steve
I've had the car out 5 times this year and had mechanical issues on 4 of them. Three times the engine began popping at about 6000 rpm and would not go past 6K under load. I'm not sure if it's afterburn or limp mode or whatever. Of course, it is an intermittent problem so I really can't tell if I fixed it until it happens at the next event. Last race, I went through practice and qualifying...worked great as long as I kept the exhaust gas temps below 1600 (I thought I diagnosed it). The green came out at the exact time the gremlin did!
I even took it to a dyno to see if I could make it happen..no luck.
So far, I've checked the resistance on the coils, crank angle sensor, checked all the grounds, put in new plugs, got "real" gas (no ethanol added), used better 2 cycle oil. New plug wires too. Changed fuel filter (but the pressure gauge was always fine), added "heat" to the fuel incase there was any water.
I do have one of the lines from the OMP that broke and will replace that today. Also, I've got a gasket problem (mating surfaces need rework)on top of the water pump housing that will be corrected today as well. As a result, I did have a little water and oil spraying around the engine compartment, but nothing drastic. Could that cause an intermittent problem?
I noticed that the trailing plugs look a bit wet and dark where the lead plugs are more brown and dry. I purchased two brand new trailing coils which I'll install today as well. At the dyno, the air/fuel mixture was good, but then again, the car worked well with a bunch of mechanics standing over it.
I have a '87 13-B S4 motor, fuel injected, non turbo built by speedsource. All pollution control has been taked off.
Can anybody give me any ideas on what to look for. The ground on the tach??? Are the auxiliary ports not opening (sometimes). My only repair manual (Haynes) says the port solenoids are driven by air from the air pump, which has been removed. I'm getting frustrated. It should not be this hard.
Your advice is greatly appreciated.
Steve