Misfire/hesitation on 1.8T

Ravinder · 22nd March 2017, 11:12

Hi guys

I've got a slight misfire or hesitation under load, around 3k refs on the 1.8 turbo 75. I will be getting the car on the T4 very soon hoping it will tell me the issue. Any ideas here what to look for? Many thanks.

T-Cut · 22nd March 2017, 11:20

Reducing the spark plug gaps to 0.5-0.7mm is reckoned to help with this.

TC

Ravinder · 22nd March 2017, 11:26

Ok, thanks. Sounds daft, but how do you measure the gaps?

suzublu · 22nd March 2017, 11:33

With a feeler gauge

or the thickness of your thumbnail

T-Cut · 22nd March 2017, 13:20

Quote:

Originally Posted by Ravinder

Ok, thanks. Sounds daft, but how do you measure the gaps?

This gap should be 0.5 to 0.7mm

You need a set of feeler gauges or a similar gap measuring tool.

And you make the gap the required size by very carefully moving the outer electrode. That's the bent bit in the first picture.

The appropriate feeler blade should just slide through the gap with a slight resistance felt.

TC

doopydug · 22nd March 2017, 14:29

Yeah - nearly always the plug gap - mine did the same Rav - easily sorted

Ravinder · 22nd March 2017, 17:40

Many thanks everyone. Will attend to if this week.

Arryhall · 22nd March 2017, 11:38

Quote:

Originally Posted by Ravinder

Hi guys

I've got a slight misfire or hesitation under load, around 3k refs on the 1.8 turbo 75. I will be getting the car on the T4 very soon hoping it will tell me the issue. Any ideas here what to look for? Many thanks.

No idea, but I have the exact same thing. It's going into the garage under warranty on Friday, but this may help meantime:

http://www.the75andztclub.co.uk/foru...d.php?t=263446

bluemalbert · 23rd March 2017, 09:26

Quote:

Originally Posted by Ravinder

Hi guys

I've got a slight misfire or hesitation under load, around 3k refs on the 1.8 turbo 75. I will be getting the car on the T4 very soon hoping it will tell me the issue. Any ideas here what to look for? Many thanks.

I have just had exactly the same problem with my 2.5 ZT. A diagnostic plug in (not as good as a T4) showed which pot the misfire was on and so I replaced that plug and coil pack as a starter. Cured immediately

So then went on to replace the rest of the plugs as a matter of keeping a matched set. You can measure the gaps with a feeler gauge set bought at any half decent auto shop. (I dont know if the 1.8 has individual coil packs like my KV6 engine!) When you have the T4 plug in, it will tell all.

Ravinder · 23rd March 2017, 20:15

Took my car up today to a good friend of mine who had a look at the car on the machine. No obvious signs of misfire showing on any cylinders. He checked the plugs and the plugs were well over 1mm. These were adjusted to 0.6mm.

Result - misfire/hesitation gone.

I no longer have a misfire, but can't help the car could be smoother. It feels through the rev range that it's not as smooth as it could be. This was present before. Any thoughts?

22nd March 2017, 11:12	#1
Ravinder This is my second home Rover 75 saloon x2, Rover 75 Tourer x2, Rover 220 Coupe Turbo Join Date: Aug 2010 Location: Kirkcaldy, Fife Posts: 9,036 Thanks: 2,278 Thanked 2,852 Times in 1,718 Posts	Misfire/hesitation on 1.8T Hi guys I've got a slight misfire or hesitation under load, around 3k refs on the 1.8 turbo 75. I will be getting the car on the T4 very soon hoping it will tell me the issue. Any ideas here what to look for? Many thanks. __________________ Wanted - Indian bride. Cash waiting. (All sorted - bargain) First name and forum name: Ravinder Rover 75 2.0 CDT Connoisseur SE 116 (160 remap) Royal Blue (JFM) This vehicle was the 50,481st 75 to run off the production line, out of 112,381 This vehicle was the 2,238th 75 CDT Connoisseur SE to be made out of 3,775 This vehicle was the 5,002nd 75 in Royal Blue (code: JFM) to be made out of 14,420 Royal Blue 75s

22nd March 2017, 11:26	#3
Ravinder This is my second home Rover 75 saloon x2, Rover 75 Tourer x2, Rover 220 Coupe Turbo Join Date: Aug 2010 Location: Kirkcaldy, Fife Posts: 9,036 Thanks: 2,278 Thanked 2,852 Times in 1,718 Posts	Ok, thanks. Sounds daft, but how do you measure the gaps? __________________ Wanted - Indian bride. Cash waiting. (All sorted - bargain) First name and forum name: Ravinder Rover 75 2.0 CDT Connoisseur SE 116 (160 remap) Royal Blue (JFM) This vehicle was the 50,481st 75 to run off the production line, out of 112,381 This vehicle was the 2,238th 75 CDT Connoisseur SE to be made out of 3,775 This vehicle was the 5,002nd 75 in Royal Blue (code: JFM) to be made out of 14,420 Royal Blue 75s

22nd March 2017, 17:40	#7
Ravinder This is my second home Rover 75 saloon x2, Rover 75 Tourer x2, Rover 220 Coupe Turbo Join Date: Aug 2010 Location: Kirkcaldy, Fife Posts: 9,036 Thanks: 2,278 Thanked 2,852 Times in 1,718 Posts	Many thanks everyone. Will attend to if this week. __________________ Wanted - Indian bride. Cash waiting. (All sorted - bargain) First name and forum name: Ravinder Rover 75 2.0 CDT Connoisseur SE 116 (160 remap) Royal Blue (JFM) This vehicle was the 50,481st 75 to run off the production line, out of 112,381 This vehicle was the 2,238th 75 CDT Connoisseur SE to be made out of 3,775 This vehicle was the 5,002nd 75 in Royal Blue (code: JFM) to be made out of 14,420 Royal Blue 75s

23rd March 2017, 20:15	#10
Ravinder This is my second home Rover 75 saloon x2, Rover 75 Tourer x2, Rover 220 Coupe Turbo Join Date: Aug 2010 Location: Kirkcaldy, Fife Posts: 9,036 Thanks: 2,278 Thanked 2,852 Times in 1,718 Posts	Took my car up today to a good friend of mine who had a look at the car on the machine. No obvious signs of misfire showing on any cylinders. He checked the plugs and the plugs were well over 1mm. These were adjusted to 0.6mm. Result - misfire/hesitation gone. I no longer have a misfire, but can't help the car could be smoother. It feels through the rev range that it's not as smooth as it could be. This was present before. Any thoughts? __________________ Wanted - Indian bride. Cash waiting. (All sorted - bargain) First name and forum name: Ravinder Rover 75 2.0 CDT Connoisseur SE 116 (160 remap) Royal Blue (JFM) This vehicle was the 50,481st 75 to run off the production line, out of 112,381 This vehicle was the 2,238th 75 CDT Connoisseur SE to be made out of 3,775 This vehicle was the 5,002nd 75 in Royal Blue (code: JFM) to be made out of 14,420 Royal Blue 75s

22nd March 2017, 11:20	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Reducing the spark plug gaps to 0.5-0.7mm is reckoned to help with this. TC

22nd March 2017, 11:33	#4
suzublu This is my second home rover 75 1.8 vvc club se wedgwood blue Join Date: Aug 2009 Location: Seaton Carew Posts: 26,922 Thanks: 65 Thanked 7,142 Times in 4,642 Posts	With a feeler gauge or the thickness of your thumbnail

22nd March 2017, 14:29	#6
doopydug Posted a thing or two Rover 75 Saloon Join Date: Nov 2013 Location: Fife Posts: 1,595 Thanks: 88 Thanked 269 Times in 235 Posts	Yeah - nearly always the plug gap - mine did the same Rav - easily sorted