My 86 n/a sort of stumbles, or jerks, light hesitation... something like that, on hard pulls above 4500 RPM.
kind of like the 3800 RPm hesitation I had in my 88. but this does it three to four distinct times up to 7000. I hate it.
I have cleaned my injectors. I have cleaned the battery posts and run a 4 gauge ground to the batt from the motor. I run 90 octane with Marvel Mystery in the gas. I have don the TB mod. I have MSD. RB header presilencer, w/ 2.5" ss mandrel all the way. K&N. Accell plug wires. I also have the timing advance over stock setting by 4-5 degrees. changes the fuel filter. O2 sensor. 6 ports wiredd cause they quit with the exhaust upgrade. e-fan.

I have thought about upgrading the fuel pump. but I don't thing that is it. I have not cleaned all the wire connections at the ecu and stuff. nor have I regrounded the ecu, just the 4 gauge ground from the batt. I am pretty sure the TPS is set. but I was thinking about checking that again when the weather drys up.
It sux because I make all the power at the top. this hesitation is killing me.


What is it?

 

no one can help me?

 

sorry can't help...

 

have you checked the spark plugs? my 87 n/a used to be horrible after about 3500 - 4000, just like how you describe it, stumbles, jerks, etc. i cleaned the plugs and it went away. it came back after a week or two so i got new plugs and leads and after that, it has been perfect.

 

I ahve changed the plugs. I think mabey I will do it again.
but some how I don't think that is it