Mivec 1.8 jerking.

[Dbass]

Hi all,
My car is jerking when I release accelerator pedal ( 1200-1500 rpm). If I press the clutch pedal, it's does not occurs. It's always happen at traffic jam. While cruising at Highway nothing problem.

 

[Izso]

What clutch you using? Modded? What gears?

 

[cucutokmex]

Is your car jerk when u stop? Try check the plug cable. If no sign of malfunction maybe ur coil is dying...

 

[Dbass]

Iszo,
I'm using semi racing clutch with standard clutch cover.

---------- Post added at 07:47 AM ---------- 6 hour anti-bump limit - Previous post was at 07:36 AM ----------

Cucutokmex,
It also jerking when I release accelerator at standstill in free gear.

Change the new plug and check the cable plug already.
My mechanic if plug coil is not stable or kaput, definitely my car cannot rev until 8k rpm. But now on standstill/free gear can rev to 8k without jerking, then rpm go down until 1300rpm have jerking. And rpm go 1000rpm with steady idling.

Sent from my GT-S7500 using Tapatalk 2

 

[levin818]

Fueling problem...
- Fuel Pump
- FPR

 

[Dbass]

Levin,
ok, I will ask my mechanic to check Fuel Pump and Fuel Regulator Pressure ( SARD). Maybe either this 2 things have problem.

 

[levin818]

If your SARD FPR is not ori... most likely that is the culprits.

 

[Dbass]

I think I bought Sard FPR in 2004, long time ago. It's original.

 

[Hadi17]

I agree with levin818 .. its most probably fueling problem

 

[Dbass]

Just now my mechanic check fuel pump & FPR and change Fuel filter. He said fuel pump & FPR still in good condition.
He said maybe nee to reTune with wideband tuning on the road, cause in low rpm to rich and high rpm is lean.

 

[Izso]

Thanks to your thread, it resolved a problem I've been having myself, similar to your problem.

When stuck in a jam, clutch in 1st gear and release clutch (release gear) the car will judder a bit. I increased my FPR and stopped the juddering.

Like your mech said, probably just need retuning.

 

[kayour]

sumtime tps oso cause such problem
try to recalibrate

 

[levin818]

IMO, TPS shouldnt be touch once calibrated from the factory.
TPS advance => Idling RPM increase, FC up
TPS retard => lag in response, power lost

 

[Dbass]

My mechanic did adjust already TPS, but still can solve the problem. Before this change already TB, also canot solve this problem...

 

[Izso]

Try retuning the car la. Especially the AFPR. Mine went from 2.2bar to 3 bar and all problems solved.

 

[Dbass]

The tuner quiet busy right now, need to wait when he is free....

 

[DanzEterna]

The tuner quiet busy right now, need to wait when he is free....

no need tuner to tune AFR can do yourself ma, get youtube to guide u, a lot of trial & errors.

 

[Dbass]

My car use VAFC, and also doesn't air/fuel meter. How I will to adjust and to know it's lean or rich every RPM?

 

[.:JiT_187:.]

Hi all,
i've exactly the same problem with yours from my 1.6 mivec
can i know what's the solution?
did u solved it?

thank you

 

[Dbass]

My mechanic adjust TPS sensor, idling sensor & timing- coil sensor...
Almost 90% solve the problem...