Spark Knocking-Anyone ever find a cure?

[Garandguy]

My 1998 Ranger (2.5, 5 spd, reg. cab 2wd) is having trouble with spark knocking at around 2000 rpms when I try to accelerate. I have put in new Motorcraft Platinum plugs, new Motorcraft wires, and EGR valve, and have checked for air leaks from the air filter to the intake.

The truck runs great at speed, but I have to have a light foot when accelerating. Other than this, and an occasional small stumble at idle, she runs like a new truck. I looked in the archives, but have found a lot of fixes without real follow up. Has anyone definitively solved this problem? Will I damage my motor if this continues?

Thanks!

 

[petter]

try putting a timing light on it with the spout disconnected timing should be at 10 btdc thats were i would start if timing is to advanced you can get spark knock

 

[scotts90ranger]

timing isn't adjustable on a '98

I would say the MAF might be dirty, if it's running a little lean it can ping just as much as if it's timing is a little off

 

[jhammel85]

MAF and maybe even the EGR is at fault.

How are the plugs and wires?

 

[scotts90ranger]

he just said he replaced the plugs, wires and EGR valve, you must have missed that sentence...

 

[jhammel85]

Sorry, I did miss that..

 

[petter]

oh sorry i read that wrong i thought he said 89

 

[Garandguy]

I have cleaned the MAF sensor, and it has a new EGR valve. It tends to knock the most when I press down moderately on the accelerator at around 1800-2000 RPMs in 4th and 5th gears. If I am really light on the pedal, then it will not knock. It also doesn't like hills w/o downshifting. I am getting 24 mpg in 50/50 city/hwy driving.

If the computer controls the timing, then how do I know where the timing is set at, and how is it adjusted? Could it be caused by backpressure from a catalytic converter that is clogging up? Could it be the EGR pressure sensor or the EGR vacuum solenoid? Can weak coils cause this? Crankshaft positioning sensor? Gas vapor on Jupiter's surface?? Dogs and cats living in harmony?

I know this engine is prone to spark knocking, but this is getting out of hand. Someone must have licked this problem before now.

Is anyone suffering from the same problem?

Thanks for the help so far guys. Hopefully, we'll come up with something.

 

[scotts90ranger]

the timing is controlled by the computer, it goes by rpm and engine load. The position is controlled by the crank pulley, it isn't adjustable unless you can change the program in the computer. Isn't adjustable on an '89 either though.

you'e lugging the engine, downshift and don't load it so far at that low of rpm. At that speed it's more considered lugging the engine than pinging/knocking. These engines are generally happier at 2500rpm and above