Hi guys, If anyone could help me that would be great After 8 years of ownership reliable ownership my RS 250 has run into its first problem. When climbing through the revs under full chat the car seems to stutter/misfire around 4/5k in most gears. Almost feels like it’s hitting the limiter. The only modifications are BMC panel filter, mid box chop and a remap by Paul at RS tuning. I’m thinking injectors or spark plugs right away and hopefully it’s nothing more serious. Anyone ever ran into problem before? Thanks
What sort of miles has it got on the clock ??? What position is the temperature needle at ??? First has to be the plugs, check the coils for cracks when you remove them.
67,000 miles on the clock. The Temperature needle sits around 1/3rd of the way up but I’ll take a picture tomorrow and put it in this thread. I’ll get all the sparks and ignition coils checked and report back Thanks
I’ll check the fuel filter, I can’t remember when it was last changed. I’ll have to check the Service book
This definitely indicates a faulty thermostat, a common issue. It stays open, preventing the engine from getting up to temperature and the ECU lowers the rev limit (in my case it was 5-5.5k rpm) when the engine is cold.
When you say "stutters" does it momentarily drop and then keep revving or is it like a hard limit it hits and you cannot rev past it?
My R26 has just suffered exactly the same problem, I have changed the plugs (gapped to .6), the coils, the N75 valve, the injectors are fairly new and are good anyway, a new low temp thermostat as the other had disintegrated in the housing. The problem persists! My mechanic finally traced the problem to the downstream lambda sensor. Got one on order, fingers crossed [emoji1696]! Sent from my SM-N986B using Tapatalk
This is what i was heading too, though mine was the upstream one. Very subtle at first, seemed like a plug or coil issue causing it to break up slightly. Left it for a bit, didnt' get worse. Eventually swapped coils and all plugs and it got wrose but no code. Then eventually while swapping plugs and coils around to narrow it down it eventually threw the lambda code and replaced that and it was all sorted.
That's good to hear! Hoping it cures mine, starting to get a bit pissed off with the amount of money I'm throwing at it. But......it still puts a grin on my face at least! Sent from my SM-N986B using Tapatalk
Heres a picture of the temp gauge, what do you think. It still revs pass 5.5k and will hit right up-to the actual limiter. It just in between days 4-5.5k if pushing hard it stutters
It just stutters for a little between 4-5.5k then continues as normal. It will still Rev to the redline. If I don’t give it full boost it will rev up without any sort of stuttering.
Thermo issues with theses so should change anyway as matter of course Same with plugs re-gap every 20k miles
Knackard thermostat, can cause all kind of running issues. When my very first thermostat started playing up, when cruising and putting your foot down, the revs used to drop and pick up like clutch slip. Thermostat went, changed it, and luckily enough that problem went aswell.
My thermostat went, hardly noticed the needle was getting lower down the gauge, the main thing i saw was the fuel consumption had gone up, changed the thermostat and got back 5-6mpg Also be aware, that if you do the thermostat yourself, you need to remove the front bumper, you need to get to the top of the rad drivers side to bleed out the air, or there is a chance that your radiator will only be 2/3rds filled.
should be ok by just opening bleed valve right next to thermostat there's also another bleed valve on water pipe heading off to cabin heater (see image)
you wont loose much water at all changing thermostat but what's easy to do is put new thermostat in wrong way round so make note of orientation
