Duratec 420 gremlin

[Collidog]

New 420R SV, 2600 miles. 

Was on the final 20 miles of a 100 mile run and on empty dual carriageway making (cough) good progress.  Proceeded to accelerate from the 12.30pm position on the speedo through to the 2pm position, which was met with vibrations and lack of shove as if the car could no longer push itself through the air.  Tried a couple of times and got the same. It was as if the fuel was down to fumes or it was on 2 cylinders.

Came off slip road in 3rd, acceleration fine as it was when joining next dual carriageway. Up into 4th car accelerated through to 2pm position on speedo no problem. Slowed down for cameras and was able to repeat the above again when back up to speed. 

Everything else fine - fuel, temp, oil pressure etc .

Gremlin or something wrong?

Thanks a lot in advance.

 

[tomwood]

Did it feel like it was kangarooing when you had your foot to the floor?

i had something similar happen on my duratec shortly after I bought it. Turned out to the HT leads. I disconnected each cylinder, disconnected every other connector I could find and reconnected it all. Never had a problem since. Worth a go.

Tom

[Collidog]

It was kind of a der-der-der-der when right foot down almost as if the fuel was cut when called for coupled with no acceleration. 

[mossy7]

*Rev limiter? 

[Collidog]

Not at that position on the speedo in 4th (5 spd gearbox)!

[Jim 123]

When you had the one off problem (which on my speedo would be between 85 up to 110) what gear were you in, and at what revs.  Could wind conditions / direction, or the gradient of the road have been working against the aerodynamic slippyness of your 7. 

[Collidog]

4th gear, so 6k-ish rpm. No unusual conditions wind or gradient etc. Was fine afterwards, but did it again later

[John Vine]

It was kind of a der-der-der-der ...

Was this something you could feel through the chassis or steering wheel, or simply the engine seeming to run rough? 

If the latter, it does sound like it could  be a misfire.  If you can manage to repeat the exercise, try to stop asap and then briefly and lightly touch each exhaust primary in turn to see if one is cooler than the others.

JV

 

[Collidog]

Thanks. Seemed to be the engine, so maybe looks like intermittent misfire. Hopefully fixed by turning the car off and on again!

[aerobod - near CYYC]

May be the throttle position sensor or the wiring to its connector giving up the ghost, especially if it is the plenum version as opposed to throttle bodies.

Vibration of the sensor in the Caterham installation seems to be somewhat beyond what Ford anticipated. I've killed 3 sensors so far on my R400D in 30,000km and carry a spare with me. Normally starts with rough running and comes and goes until the engine won't run properly at all. You can see the voltage not changing smoothly as the throttle is opened and closed when using Easimap to view engine parameters.

[SM25T]

I wouldn't want to "touch each exhaust primary" however lightly and briefly. I would use a contactless laser thermometer though.

[rj]

I've seen a 485R where one of the connectors on one of the coils failed at certain revs. Try to wiggle the connectors for injectors and coils and see if it turns three-cylindered.

[John Vine]

(Point taken, Ian!  Unfortunately, my toolkit doesn't include a fancy thermometer.)

If it does turn out to be a misfire, there are several well-known possible causes (all of which have happened to me):

• TPS failure (as James correctly states)
• TPS wiring failure (ditto)
• Coil-on-plug (COP) failure (typically on #1 cylinder for some reason)
• COP wiring failure (ditto)
• Spark plug
• Spark plug gap (too wide)

As your car is so new, any of the first four would be a warranty issue.

Are your plugs the FoMoCo (NGK) TRAP6-13?  If so, there have been reports that the gap (1.3mm) isn't very kind to the COPs and can lead to breakdown due to the very high voltage required.  You could try using NGK BR7EFS plugs instead (set to 0.9 mm).

JV

 

 

 

[Collidog]

Checked all connectors - coils, TPS etc. All as it should be. Had plugs out. They are FoMoCo, but all perfect condition as you would expect. 

Ran engine and all fine when twidling around with the connectors. 

Will just have to see if it happens again and call CC if it does. 

[Geoff Brown]

Had a similar experience with my R400D several years ago - at certain RPMs a distinct 'miss fire' or 'miss fueling' episode when the engine was hot. Very little power & hesitant acceleration.

Strangely this usually occurred when driving at night which suggested to me that it was electrical & that the lighting system may be causing a low battery voltage supply to the ECU. I believe the ECU can only survive operating normally above 4.5 volts?

Tested the alternator & battery. I concluded that the battery was possibly beginning to fail to hold or maintain charge. A few days in the garage without driving confirmed the battery state - not enough charge to start up.

Replaced the battery & all has been fine since.....until this Banner battery decides to fail. Well they do have an average life of about four years!

[ChrisC]

Obvious stuff first, is it under warranty?   If it is then get CC to look at it.

If not, and you can reproduce the problem at will (on the right road ), then try and find someone with the MBE lead and see what the ECU thinks its doing.   It wont give you an error code, but with the data logger, you should be able to tell what the problem is from the data captured. 

So in the example above you would see the battery voltage drop, or even the ECU reset count increase.    I diagnosed a friends car which stalled for no reason at random times, we eventually captured the data needed and could see the injection pulse increasing and increasing, with the lambda getting leaner and leaner, as if it was running out of fuel, caused by the faulty inertia switch.

Final option take your car to Track n Road in Rainham Essex, they have the Caterham software so can deal with your locked ECU.  According to reviews on here you won't regret the result.   

[Collidog]

This intermittent misfire was finally traced back to ‘very poor crimps’ on both battery terminals. CC replaced with new terminals, re-crimped and soldered. 

[ChrisC]

Good work CC

[Tazio]

Why good work CC?, shouldn't the crimps have been done properly in the first place?

[ChrisC]

Do you think they make the leads?   If the car cranked and fired I would have thought the batter connections would have been fine, so that would not have been on the top of my list when checking for poor engine running problem.   In my book finding that seemingly unrelated component failure is good work. 

Obviously  some people like to blame CC for all faults, but the truth is our cars are made up of many components from many suppliers.   I had three warranty claims during my cars first two years, gearbox, shock and calipers, each component was supplied to CC in a box and then supplied to me in good faith.   If the component had been manufactured to spec then my cars would have been warranty claim free, but it wasn't.   And before anyone says obviously CC cut suppliers margins to the limit, and this is the reason quality control is poor with parts suppliers, think of the buying power of CC, then think of the buying power of main stream car manufactures.   I know Ford buys starter motors for about £10, the same starter motor on our Duratec cars, but try and replace our starter motors for that.  

[John Vine]

I think that's a very fair comment.

JV

[7 wonders of the world]

These could have been a one off however CC are still responsible for parts they sell - weather they make them or not and as such should have suitable QC procedures in place to minimise these during manufacture and at delivery too.

[ChrisC]

I am in no doubt CC are responsible for components supplied to me, and since I fitted all the components supplied, am I at fault for not checking the quality of my Bilstein nearside rear shock?   It was fault free during the build and IVA, but failed at 2500 miles, how could I have spotted that.   How could collidog (or the builder of his car) test at 12:30pm + speeds?

Main stream manufacture don't check the quality of every parts being fitted, they just test samples.   And I am sure if a new suppler comes on stream supplying batter leads to CC they will check the components they are purchasing, but that doesn't stop a fault batch leaving the supplier and ending up in kits or on cars after an establish supplier has a problem.   Not sure I checked the crimps (under the heat shrink) on my supplied battery leads.   If you follow that logic, you would have to dismantle the loom to check all wire joins.   

It's easy to blame CC, and in a perfect world every part would have a full QC process with sign off, but how expensive do you think that would make cars?    Imagine a world without Takata airbag recall style scandals.