tim.howard Posted January 2, 2018 Share Posted January 2, 2018 HiThis is my first year with a Caterham, I put the car away around a month ago to avoid road salt, in a garage with boiler and on a battery charger. Over the weekend the temptation got too great and i decided to go for a run. At start up she coughed and spluttered a little, I thought it would clear as she warmed on the run, but anything more than half throttle saw reduction in power and uneven running with the odd back fire... sadly after 20mins I was back in the garage with minor idling problems too. Also if I hold a steady throttle at say 3.5k revs then the revs gain gradually to the red line.Any thought on how to cure welcome.Tim Link to comment Share on other sites More sharing options...
oilyhands Posted January 2, 2018 Share Posted January 2, 2018 Check the connection to the throttle position sensor first, these are known to break down.Oily Link to comment Share on other sites More sharing options...
revilla Posted January 2, 2018 Share Posted January 2, 2018 Does sound like the ECU is not getting the right picture of what the engine is doing ...Definitely check the TPS wiring as above.Just a few additional thoughts:Is the engine EU3 or EU2?EU3 will have coils on top of the plugs, a big plastic cover on top of the engine that covers about half of the metal cam cover to protect the coils, and just a thin low voltage wiring loom entering this from the rear. Probably a wedge-shaped ECU with two black connectors. EU2 will have a coil down on the side of the engine, just a thin plastic strip cover down the centre of the cam cover with 4 HT leads leading under it from the coil. Probaby a box-shaped ECU with one black and one red connector.If EU3, you can plug an OBDII diagnostic scanner into the diagnostic connector which should be somewhere round about the driver's right knee, probably just dangling loose from the wiring loom and probably hiding behind the knee trim panel. Unfortunately the MEMS2J ECU used on the EU2 VVC engine didn't support OBDII. OBDII scanners with "live data" facility can be had very cheaply on eBay and will allow you to see what information the ECU is getting from its various sensors.Have a look at any error codes logged. Don't panic, there will probably be a few anyway as the ECU doesn't know it's in a Caterham and not a Rover, so it tends to log faults with systems that are simply missing like post-cat oxygen sensors etc. Post up what you find on here and people will be able to tell you if there's anyting to worry about.In particular, for sensor data I'd look at:TPS - If calibrated correctly this should say 3.92% at idle and increase smoothly to 90-something-% at full throttle. You can do this with the engine switched on but not running.MAP - These should read something fairly low (I think from memory around 30kPa) at idle. Under heavy throttle out on the road this should rise to close to 100kPa (atmospheric pressure) and drop to an even lower value, maybe 23kPa, on the overrun.Possibly IAT (but I doubt it would give those problems) - should read something reasonably close to the outside temperature, but they're never terribly accurate and under-bonnet air may be warmer too, so don't worry if it's a bit out, but I had an issue where one was disconnected and it read -40°C which was clearly wrong. That's the sort of gross error you are looking for.If the car is driving along nicely on very low throttle, then you suddenly floor it, does it run rough immediately or does it got for a second or two then deteriorate progressively? If the latter, could be a blockage in the fuel filter, the fuel delivery won't meet demand and the pressure in the rail will fall away. Just wondering if you've had a settling of sediments in the tank which it's been in storageThe air filter is in good condition? No chance it is getting wet where you are storing the car? You could do a brief test without it to eliminate it as a source of the problem but I wouldn't run like that for long. Link to comment Share on other sites More sharing options...
SM25T Posted January 2, 2018 Share Posted January 2, 2018 Lambda sensor maybe. Unplug connector and see if it then runs OK. If so .... find etched number off it and buy on eBay. Link to comment Share on other sites More sharing options...
tim.howard Posted January 6, 2018 Author Share Posted January 6, 2018 TPS arrived this morning and replaced + recalibrated per various Rover blogs (5x throttle opening while ignition switched on but not fired up...)Problem persistedI've now disconnected the Lambda sensor and gone for a run and all was fine.I'll now replace...thanks all Link to comment Share on other sites More sharing options...
SM25T Posted January 6, 2018 Share Posted January 6, 2018 Good news. Same happened to mine. Easy fix. Link to comment Share on other sites More sharing options...
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