Rough running
Thread Starter
3rd Gear
Joined: Apr 2010
Posts: 3
Likes: 0
From: Letcombe Regis Oxfordshire
Rough running
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Hi there, new member here,
I've got a worsening problem with my car and I was hoping that you could point me in the right direction to fixing it.
Some history:-
It's a 1994 with a manual gearbox. When I bought the car it was fitted with a Hypertech (Non-adjustable) piggy-back chip.The car was running as though the timing was slightly out and the 'SYS' light was flashing continuously.On advice of a mechanic friend, I removed the chip and the fault disapeared.Iwas told by the previous owner that the person that HE had bought the car from had fitted the chip along with larger injectors, I have the receipts for the chip plus quite a lot of other bits bought at about the same time but not for the injectors which seems a bit odd so I have to take the larger injector story at face value only.
I replaced the standard headers with some " Shorty" ones and, on the advice of the same mechanic friend, removed the EGR pipework and blocked off the intakes in the headers and back of the plenum chamber. I also reversed the intake/output pipework on the air pump so that it now draws from atmosphere and blows into intake manifold,post filter (Working on the 'why not' principal)
Because the headers made the car sound so much better than I was expecting, I then had the centre silencer replaced with 2 straight pipes making it a true dual system.
The car has recently started missing slightly under part or light throttle openings (Cruising at 50/60 MPH or accelerating gently)Occasionly the car will suddenly start juddering whilst cruising along at a steady 50/60 MPH in sixth as though trying to climb a gradient in the wrong gear.If I push the throttle harder or drop down a gear, the problem goes.
When I get back from a run, I have noticed that the right hand tailpipe is black whilst the left one is a very pale grey.
On starting up from cold, the sound from the tailpipes is very even and properly "V8", as the engine warms up, the right-hand pipe starts to sound more and more "Woofly" ending up sounding very flat and un-"V8ish"
I have changed the plugs (Cheapest option first,of course!) and, although it now starts better, it hasn't cured the poor running.
I have cleared and then checked the engine diagnostic (Paper clip) and it has stored fault codes 4.63 and 4.64.
I have been on several sites and it has been suggested that it could be either the dredded Optispark or that the exhaust pipe now has no balance pipe.
Could it be the O2 sensor or, maybe the temperature sensor telling the ECU lies?
Any thoughts would be very welcome.
Andy Crosby.
Hi there, new member here,
I've got a worsening problem with my car and I was hoping that you could point me in the right direction to fixing it.
Some history:-
It's a 1994 with a manual gearbox. When I bought the car it was fitted with a Hypertech (Non-adjustable) piggy-back chip.The car was running as though the timing was slightly out and the 'SYS' light was flashing continuously.On advice of a mechanic friend, I removed the chip and the fault disapeared.Iwas told by the previous owner that the person that HE had bought the car from had fitted the chip along with larger injectors, I have the receipts for the chip plus quite a lot of other bits bought at about the same time but not for the injectors which seems a bit odd so I have to take the larger injector story at face value only.
I replaced the standard headers with some " Shorty" ones and, on the advice of the same mechanic friend, removed the EGR pipework and blocked off the intakes in the headers and back of the plenum chamber. I also reversed the intake/output pipework on the air pump so that it now draws from atmosphere and blows into intake manifold,post filter (Working on the 'why not' principal)
Because the headers made the car sound so much better than I was expecting, I then had the centre silencer replaced with 2 straight pipes making it a true dual system.
The car has recently started missing slightly under part or light throttle openings (Cruising at 50/60 MPH or accelerating gently)Occasionly the car will suddenly start juddering whilst cruising along at a steady 50/60 MPH in sixth as though trying to climb a gradient in the wrong gear.If I push the throttle harder or drop down a gear, the problem goes.
When I get back from a run, I have noticed that the right hand tailpipe is black whilst the left one is a very pale grey.
On starting up from cold, the sound from the tailpipes is very even and properly "V8", as the engine warms up, the right-hand pipe starts to sound more and more "Woofly" ending up sounding very flat and un-"V8ish"
I have changed the plugs (Cheapest option first,of course!) and, although it now starts better, it hasn't cured the poor running.
I have cleared and then checked the engine diagnostic (Paper clip) and it has stored fault codes 4.63 and 4.64.
I have been on several sites and it has been suggested that it could be either the dredded Optispark or that the exhaust pipe now has no balance pipe.
Could it be the O2 sensor or, maybe the temperature sensor telling the ECU lies?
Any thoughts would be very welcome.
Andy Crosby.
