1.8 miata intermittent jerking acceleration
 

Hello! I haven't been on in a while since i sold my 1.6 turbo miata several years ago. I just purchased a 1990 miata with a 95 1.8 motor using flyin miata swap components. I have already searched this and I can't find an answer for it. Intermittently, after I have already fully let off the clutch mind you, the car will jerk upon acceleration in first. This sometimes follows into second gear and usually mellows out by third gear. It is really annoying and I can't figure out what it is. I thought it might be a misfire or fuel cut of some sort. I purchased and installed new spark plugs with no changes. I then purchased a new fuel pump thinking it might be cutting fuel with no changes. The car already has NGK blue spark plug wires but i decided maybe they are old so i purchased new wires as well. They haven't come in yet but I will see. I am thinking it is either the wires, the air flow meter, or the fuel filter. Has anyone come across this issue before?

- Ben

what ecu?

It has the stock 1.6 ecu right now (as per previous owner). I want to get a megasquirt because the plan is to go turbo and lose the AFM.

Update.

I installed fuel filter with no changes. I'm thinking it has to be the tps or the afm.

Please see video and disregard what I'm saying. I meant to say the the clutch is fully engaged at this point.

Also I'm getting 23 mpg average mostly highway and that equated to about 179 miles for this tank give or take. Not sure if this is normal or not because my other Miata only ran after the turbo install. It seems low to me though.

New update! Spark plugs wires came in last night. Fixed all jerking as of now. (Knocks on wood). Now I can start the turbo build.