Street King

Hey team,

It just started happening recently. I get this chugging of the car only when cruising. This does not happen on deceleration or acceleration, just when I'am at a constant speed(on the lower RPM's). It almost feels like it's not receiving fuel, but why? It does at WOT and is idles perfect with 17 on vacuum.

Also this doesn't happen all the time. This morning it was fine but last night it was doing it and the day before. I changed the fuel filter and plugs not too long ago. I can't see why it would be the filter seeing as it would happen more so at higher speeds and not just at cruising speeds.

Can't see why it would be the plugs because it pulls to redline just fine. I know my pulsation dampner is going to need replacement soon, would this cause my problem. The chugging wont go away, it just chugs till I throw it in nuetral, accelerate on boost, or decelerate. Would a faulty air pump cause this. I disconnected my air pump and it was fine before. getting a shorter belt to run wiht out it.

Thank you for your help,
Jonas

rynberg

how old is your 02 sensor?

Could be pressure sensor or a problem with the injectors.

Street King

Changed the 02 sensor like a month ago to a universal bosch. What and where is the pressure sensor? If it was the injectors I would think it would hesitate in boost. A/F gauge reads well into the green, I know thats not the scientific approach but it does mean it's recieving a good amount of fuel. Could be a bad batch of fuel?

Street King

tippy top

duckyjp

Is this problem like the one described in this thread?

https://www.rx7club.com/forum/showth...ghlight=buckin

I had these symptoms and they are completely gone after I added a ground from the negative battery terminal to the chassis and replaced the one from the firewall to the uim. It has been a few months and they are still not back. I am also planning on replacing the ground down on the cat.

If you have any questions feel free to shoot me a pm.

Street King

Thanks, very good posts! I was thinking it was the ground because when I gutted my main cat I was tooling with the ground and the one in the engine bay. I'll redo those 2 and add another or maybe more. Damn something this simple should have been addressed by the so called engineers at Mazda.

mblachford

These cars have a notorious grounding problem that results in about a 3k RPM hesitation if I remember correctly. There are aftermarket grounding kits you can purchase. In fact I think Pettit will send you a free one with any order, but don’t quote me on that.

mike5876

auto zone for about $3

bajaman

Oh yeah, I would have to say it is a ground problem. Mine did the same thing. I ran a ground like shown below, plus a 2 guage cable from the negative battery post to a ground on the chassis.

93 R1

Disconnect your o2 sensor.

It fixed mine.

Street King

No thanks!