i have a 89 turbo ll mods are walbro pump,fcd, rewired fuel pump,eng rebuilt 6 months ago (street ported) racing beat full exhaust.if you go at a constant speed above 3500 rpm it starts to buck ,you can hear it in the exhaust popping ,saturday i adjusted tps with the tool from mazda ,the car idles fine ,car has new fuel filter ,spark plugs and spark plug wires are 6 monts old , inj were cleaned 6 months ago by rc eng.
codes strored are 1,18 ,33
i installed a new thermosensor with a brand new connector saturday.
what wire is the ground to the trailing coil?
where does the tach feed from?is it the crank sensor or the trailing coil?

any suggestions ?please dont hesitate!

 

car also smokes white when the blow off valve goes off
the voltage to the fuel pump is in specs

 

The car's body grounds the coils. They must be bolted onto the body.

Quote:

where does the tach feed from?is it the crank sensor or the trailing coil?

Trailing coil, yel/blue is the tach feed for all the accessories like the dash tach, power steering computer, etc.

 

how can i check the yelloe blue wire ohm or voltage?

 

set your digital multi-meter for AC voltage, and ground the negitive lead of your meter. The voltage should increase and decrease with engine speed.

Or if you have a meter with a tach input, just hook up right on it

 

forgot to mention that when vech is turned off hot it will flood,the injectors were cleaned by rc eng 6 months ago .

 

i have the exact same problem with my car. i would like to know what is wrong also

 

I the vacum line for your crank case pressure still hooked up to your turbo inlet duct and is the check valve still good? Also do you have the stock boost pressure sensor still in the car( located on passenger side fender under hood)? Does it still have the stock oraface in it(little round plastic piece in boost line)? If the check valve for your crank case pressure line is bad you will have trouble starting your car. It make it feel like your not keeping fuel pressure. Also the orafice will make your engine buck if it is not installed. You can get one from you local dealer for about $2.88. When they pull up the parts screen it will be under the intake section.

 

Bzzt

I used to think the same thing. The ground is the spark plug. The coil builds up a current field, then when it gets the "fire" signal from the ECU it sends the output to ground, which is the engine. On the way to ground, the current jumps a little gap called the spark plug, igniting the mixture. Pretty ingenious, eh?

Dale

 

i have the press sensor and the one way valve installed

 

Okay... try running the car without the coils bolted in and tell me if it still runs okay

 

ill do that after work thanks