Engine not behaving like it should

[robgooch]

I have a 2001 172and today I was driving down the dual carriage way at about 60 mph and went to accelerate to 70 mph. In 5th gear with my foot flat to the floor it gained speed and revs but just before 70 with my foot still flat to the floor the revs dropped along with the speed. I removed my foot of the accelerator pedal and press down again and it was ok again.

I thought it was connected to revs and went limp at 3000 rpm, but I did get it above 3k. I dropped down to 3rd gear and I managed to get above 3k and 70mph, so neither were a barrier. The engine was warm too.

I have had the heart beat monitor illuminate a couple of times upon start up and the revs stuck at 2000 rpm, but it's not done that for ages.

No lights illuminated when it went limp at 70mph either. I'm fairly new to Renault ownership so if someone could shed any on my problem.

Looking into the cars history the plugs were changed at 72000 miles in August 2011, it's now on 84,000. Are the recommended plugs platinum or standard does anyone know?

I also have a receipt from January 2012 for a throttle body and throttle pedal from renparts changed at 77000 miles.

From June 2012 it had a top inlet manifold from renparts and 2 lambda sensors from northwest performance.

As you can see its had a lot of bits changed so it could be one of those at fault as I assume the renparts bits are 2nd hand.

Any ideas would be greatly appreciated.

Thanks,
Rob

 

[Aluco]

You've not got the limiter turned on and set to 70 have you? haha

 

[robgooch]

Thanks for the input but I did exceed 70mph so it's not speed related.

 

[DrR]

Has it only done it this one time?

 

[robgooch]

Yes it has, I was on a 25 mile journey got about 7 miles down the road before I turned around and swapped it for my girlfriends car.

 

[DrR]

If its only done it once, wouldn't worry, French cars do crazy things.

 

[robgooch]

Haha I've gathered that bit, I've only had it since August, but ive had a couple of strange thing happen. Perhaps I will take it for a spin, see what happens.

 

[robgooch]

Just come in from taking it for a spin. Didn't even get off the drive. It started first time as per normal but the revs just hunted between 1600 and 2000 rpm. I did what I've done before when that happened and I turned the engine off and then restart the engine,but on this occasion it didn't restart. It just cranked over with the eml and hearbeat light illuminated. It would have continued to crank over until the battery went flat I think. Any ideas?

 

[Alex H]

has it had the crank position sensor done? that usually sorts out the bad starting iirc.

 

[robgooch]

Yes, I seem to have a receipt for 2 of those one from ECP and one from GSF only a couple of days apart. At the moment I can't rule out that any part that has been changed has not gone faulty again. I'm going to start today by cleaning the throttle body this morning and go from there.

 

[robgooch]

Went out to clean the throttle body this morning and before I started I started up the engine. It fired first time and idled at the correct rpm. The only problem is that the orange eml is on to the right of the speedo dial. I didn't fully remove the throttle body I just removed the air intake pipe and cleaned around the bore and the butterfly as best I could. Once back together I took it for a test drive and was fine around town even though the eml was still on. It was only when I got on the dual carriage way it did what it did yesterday and when it got just over 60 mph it went flat. You can drive through it and the revs pick up again, the a few moments later is does the same. When I got back home I shut the engine off and the fired it up again, it started first time. But at least the eml is staying on, so I can get a code reader on it tomorrow.