Firing/ignition issue
Discussion
Hi Everyone,
I have had my 1997 Chimaera 400 (Serp) for 3 years now without any issues. Recently I noticed a bit of misfire, when the car was warm and going slowly, it got a bit stuttery at low revs. I tried to fix this myself by fitting Magnecor leads, a new rotor arm and distributer cap, and new ignition barrel. I also cleaned the stepper motor, and fitted an Act silicone elbow from the AFM and a heat shield for the AFM, and a new Bosch HSB075 battery. After spending all that money, the car now struggles to start! I have to give it a bit of throttle and turn the key for 10 seconds or so to start it, then it smells pretty rich when it's going. Also noticed the fuel tank drop quicker than normal, but I had put that down to running premium for a change (difficult to get premium out in the sticks).
My theories from reading on this forum are that it may be something to do with the Throttle Position sensor, or throttle pot, or it could be a slight mis-timing issue, or an issue with the lamda sensor (which may have been damaged along with all the skin on my hands when I replaced the exhaust manifold gasket), which floods the engine on running.
The spark plugs are pretty new so shouldn't be them. Another thing I've noticed is it used to beep when I turned the ignition off, and it no longer does this. Also when idling (which it does pretty well), if I open the throttle progressively it is fine, but if I press it quickly it stutters and hesitates, and the engine shakes the car a bit before it does anything.
I could keep up my current fixing technique by replacing everything, or ask some people that actually know what they're talking about (you guys). I also need to get a multimeter to do some checks. Can anyone help/sympathise?
Alex
I have had my 1997 Chimaera 400 (Serp) for 3 years now without any issues. Recently I noticed a bit of misfire, when the car was warm and going slowly, it got a bit stuttery at low revs. I tried to fix this myself by fitting Magnecor leads, a new rotor arm and distributer cap, and new ignition barrel. I also cleaned the stepper motor, and fitted an Act silicone elbow from the AFM and a heat shield for the AFM, and a new Bosch HSB075 battery. After spending all that money, the car now struggles to start! I have to give it a bit of throttle and turn the key for 10 seconds or so to start it, then it smells pretty rich when it's going. Also noticed the fuel tank drop quicker than normal, but I had put that down to running premium for a change (difficult to get premium out in the sticks).
My theories from reading on this forum are that it may be something to do with the Throttle Position sensor, or throttle pot, or it could be a slight mis-timing issue, or an issue with the lamda sensor (which may have been damaged along with all the skin on my hands when I replaced the exhaust manifold gasket), which floods the engine on running.
The spark plugs are pretty new so shouldn't be them. Another thing I've noticed is it used to beep when I turned the ignition off, and it no longer does this. Also when idling (which it does pretty well), if I open the throttle progressively it is fine, but if I press it quickly it stutters and hesitates, and the engine shakes the car a bit before it does anything.
I could keep up my current fixing technique by replacing everything, or ask some people that actually know what they're talking about (you guys). I also need to get a multimeter to do some checks. Can anyone help/sympathise?
Alex
I will have to read up on that. I had an auto-electrician look at it when I changed the leads, as the firing order (on the distributer) was different to that in the "bible", and he seemed to think the timing was good then. He took the distributer cap off and watched it move when I turned the key, and then he basically found the firing order by trial and error until 1 cylinder fired. It sounded rough when we first got it going, but since then I've had several long drives before this issue started. Sorry I'm not up to speed with the details of timing.
I thought the firing order was the same on all the rover engines. If the firing order is wrong it may well run and give the symptoms you are describing. Here is a diagram and order
http://t3.gstatic.com/images?q=tbn:ANd9GcSqglsKAEQ...
1,8,4,3,6,5,7,2.
The position for number 1 is at 7 o'clock if you look at the distributer from the n/s and the rotor arm rotates clockwise.
Hope this has helped
http://t3.gstatic.com/images?q=tbn:ANd9GcSqglsKAEQ...
1,8,4,3,6,5,7,2.
The position for number 1 is at 7 o'clock if you look at the distributer from the n/s and the rotor arm rotates clockwise.
Hope this has helped
Alex,
If it's running rich I would look at the ECU temperature sensor and make sure that is feeding the correct voltage to the ECU. (Easy to check with a multimeter on resistance range) They are quite a common problem as they can give the ECU the impression that the engine is still cold so over fuels quite a bit and can cause hot starting issues.
Its the one located near the dizzy with a mini timer connector not a spade or pin type connect like the gauge temperature sensor. Cheap to replace too.
It might be worth checking the AFM connector especially if the connector water proof boot is missing.
Good luck.
Paul.
If it's running rich I would look at the ECU temperature sensor and make sure that is feeding the correct voltage to the ECU. (Easy to check with a multimeter on resistance range) They are quite a common problem as they can give the ECU the impression that the engine is still cold so over fuels quite a bit and can cause hot starting issues.
Its the one located near the dizzy with a mini timer connector not a spade or pin type connect like the gauge temperature sensor. Cheap to replace too.
It might be worth checking the AFM connector especially if the connector water proof boot is missing.
Good luck.
Paul.
Check and clean the AFM. Have you checked or changed the air filter?
Clogged or partialy blocked air filter will let the car start and tick over but run rich and with sometimes a slight hesitation or misfire.
Would not run if the firing order was out it would pop and bang through misfires.
Firing order if it helps.
Clogged or partialy blocked air filter will let the car start and tick over but run rich and with sometimes a slight hesitation or misfire.
Would not run if the firing order was out it would pop and bang through misfires.
Firing order if it helps.
Thanks for all your suggestions, ive been playing around with it today, the firing order is all good, took the AFM out and cleaned it up, took air filter out which seemed fine (a bit of slimy stuff on it but I turned it around so that is at the back). Also cleaned the connectors on the ECU temp sensor and AFM and sprayed wd40 on the throttle pot. It started fine and seemed to be idling well and smelling normal. Could also have been the good run out I gave it yesterday, but for now its going well. Not going to celebrate until its run without problem for a while, as there may be some relay or something on its way out.
Update, after one good run the car returned to its starting issues, would run ok once started but took a lot of time and gas to start. Spent a lot of time trying things, trial and error with no joy, was about to order a ignition module when I read on here that they can be quite particular about rotor arms. I took the brand new one I got from ACT out and replaced it with the old Lucas one and it fired up straight away! I'm not saying anything against ACT as everything else ive had from them has been top draw, but this rotor arm must have been faulty. Anyway Im happy to have the car back!
Alexc1984 said:
Update, after one good run the car returned to its starting issues, would run ok once started but took a lot of time and gas to start. Spent a lot of time trying things, trial and error with no joy, was about to order a ignition module when I read on here that they can be quite particular about rotor arms. I took the brand new one I got from ACT out and replaced it with the old Lucas one and it fired up straight away! I'm not saying anything against ACT as everything else ive had from them has been top draw, but this rotor arm must have been faulty. Anyway Im happy to have the car back!
Result. Its damn frustrating when you have tried everything and then find it to be something small... although, at least its a cheap part!Or by learning from the master.
Try saying "I'm really keen to learn more about my car - can I watch please and will you talk me through what you are doing?".
I was wielding spanners on mine "helping" my TVR expert last weekend, trying to resolve a fuelling issue, and then again on Tuesday i watched while Rob Robertson (mr V8 Developments) was trying and succeeding in resolving a stalling issue. These guys are enthusiasts too and generally like you taking an interest
Try saying "I'm really keen to learn more about my car - can I watch please and will you talk me through what you are doing?".
I was wielding spanners on mine "helping" my TVR expert last weekend, trying to resolve a fuelling issue, and then again on Tuesday i watched while Rob Robertson (mr V8 Developments) was trying and succeeding in resolving a stalling issue. These guys are enthusiasts too and generally like you taking an interest
You are very right, but not for my scenario. I live in Pembrokeshire where the nearest tvr specialist is quite a distance away, I have been using a classic and sports car specialist recommended by someone on the tvr cc forum, but refuse to take it back to him after he took 2 weeks to change my headlights and ended up using silicone sealer with temporary tape which took my days to get the remenant bits off the paint work, and whilst washing the car today the light fell into the car! Fuming! Plus he messed up a radiator replacement, installing it without the bobbins and putting a block of wood underneath as a substitute, so inevitably it moved on the run and leaked a load of coolant. I asked him to do the exhaust manifold gasket and he said no as it was too tricky. I ended up fixing all of those shortcuts and doing the manifold gasket. Also my ignition problem started whilst I was trying to fix a stutter which is now gone courtesy of the magnecor leads, plugs, shrouds, plenum elbow, coil and new dizzie cap. So all I lost out on was a rotor arm and coil which may not have been needed, but all the bits removed looked tired and were probably paid for by the lack of labour costs. The big bonus for me though is that I know my car so much better now and enjoyed the troubleshooting, and all tasks were done with pride! Car has never ran a smooth as it does now. Don't get me wrong though, if someone can recommend a good garage near Pembrokeshire then I would be very grateful!
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