Tomiam Posted October 5, 2015 Author Share Posted October 5, 2015 Advice duly noted. Sadly the garage close to me didnt have a tap that big so Im waiting on a lambda sensor thread repair kit to arrive in the post. :) Link to comment Share on other sites More sharing options...
Tomiam Posted November 1, 2015 Author Share Posted November 1, 2015 Update: 3 weeks ago I replaced the lambda sensor and the corroded pins within the connector block. Initially it appeared to have fixed the issue and she ran fine for 30 min test drive. I already had her booked into Williams Automobiles for a flat floor & geometry session. Whilst up there she again repeated the same symptoms so it isnt the lambda sensor..... They are investigating the issue and looks like it the alternator. If I understand what they said correctly, anything below 4k rpm and the battery is going down in power as its not supplying anything to the battery. Once above 4k rpm the alternator then springs into life and the car is running on that instead of just the battery. Once its comfirmed I'll post it back with information in the hope it helps someone else. Link to comment Share on other sites More sharing options...
BAZZA Posted November 1, 2015 Share Posted November 1, 2015 Have you checked the sub loom that goes into the rear of the spark plug cover, I had a similar problem some time ago and it was a broken wire. Try looking there I had a broken wire. Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted November 2, 2015 Member Share Posted November 2, 2015 If I understand what they said correctly, anything below 4k rpm and the battery is going down in power as its not supplying anything to the battery. Once above 4k rpm the alternator then springs into life and the car is running on that instead of just the battery. How are you planning to investigate... how about measuring battery voltage against engine speed both cold and warm?(Some thoughts about alternator problems and pulley size and quality of connections, but let's start with narrowing it down a bit.)Jonathan Link to comment Share on other sites More sharing options...
Tomiam Posted November 2, 2015 Author Share Posted November 2, 2015 They are going to test it once the alternator is replaced. At the moment its not giving hardly any charge unless its above 4000rpm. Easy to test once its been replaced. Link to comment Share on other sites More sharing options...
Tomiam Posted November 10, 2015 Author Share Posted November 10, 2015 Update.... /sigh. Alternator replaced - car is now charging the battery at any rpm whereas the old one wasnt. However... its still running like a bag of crap at anything below 5k rpm. Its with a garage at the moment who are waiting on a call back from Caterham to help diagnose it. Summary: Car bought six months ago. R400D with Roller barrel throttle bodies. A month or so ago it would intermitently run very rough at low rpm and then seemed to fix itself. Started with 2 - 3 seconds of spluttering as if the engine was dying and over time this has gotten much worse to the point that its now undrivable. At <5k rpm the exhaust is making a bangbangbangbangbang! noise, as if its detonating fuel in the exhaust. Feels like over fueling. No power at all at this point. If I floor it, then once it gets to about >5krpm then the car accelerates like mad. It also runs very rough at idle now. To remedy this I / the garage its at have so far:-Replaced the lamda sensor (genuine caterham one) Replaced all spark plugs. Checked all connections and replaced pins on a corroded connection block to the lamda sensor. Replaced throttle position sensor Replaced alternator Rebalanced the throttle bodies Any thoughts welcome. Im sure the garage its at will get there but in the mean time if anyone else has had an issue like this Id very much like to cut down my labour bill with them... @Bazza. I believe this has been checked. Thank you though! I will double check with them. Link to comment Share on other sites More sharing options...
Jim 123 Posted November 11, 2015 Share Posted November 11, 2015 Sediment in the fuel tank/system/blocked injector? Crankshaft position sensor failing or related wiring connector corrosion? Has the exhaust system detonation damage the Catalyst? Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted November 11, 2015 Share Posted November 11, 2015 Hi Tomiam,From an ECU perspective I would check all your grounding and continuity between your ECU plug and the sensor end of the wires using a multimeter, anything higher than 0.5 of an Ohm would be suspect. I would also confirm that the voltage from the grounding terminal on your fuse block to the battery negative and to the engine block is as low as possible while the engine is running (10 millivolts or less is ideal).If all your grounds and sensor cables are good, it is best to borrow or buy the MBE canbus cable to hook up to a laptop to look at what is happening on the road. It is best to have someone driver the car while you give them instructions on what to do while looking at throttle voltage, lambda setting etc. Better still to take someone who understands engine tuning. You can also save the data logs for analysis once home. Making sure the throttle as at the right throttle site for a given acceleration, lambda values are correct in steady running and all your sensors are giving realistic values will enable you to home in on the problem.It really is worth the £100 cost for the MBE cable, if you don't already have it. Link to comment Share on other sites More sharing options...
Jim 123 Posted November 12, 2015 Share Posted November 12, 2015 Have the spark plug coils been checked? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now