Desperate help with misfire

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Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Desperate help with misfire

Post by Sbsoulby »

Hi guys, I'm hoping for some of your wisdom, because I have none

My car is a rev 3 1995 turbo all pretty much standard barring the usual engine mods, exhaust, intake and bov

I've got a misfire/hesitation, it's mainly when pushing the car hard and in boost, more so in 2nd and 3rd gear

I've already changed all the ignition. Grade 7 plugs, genuine ignition leads, genuine rotor arm and dizzy cap, and a new genuine king lead, I've had a look at and set the timing to 10 degrees
I've also checked for any vacuum leaks and I think it's all good also changed the valve cover gasket

If I drive the car steady it picks up fine even if I drive it steady until high rpm so it's only when it's during hard boost

Just wondering what else I need to check, I'm close to Scunthorpe if anyone is in the area and is willing to have a quick look

Thanks
pnelson
Posts: 66
Joined: Sat Feb 13, 2016 12:07 am

Re: Desperate help with misfire

Post by pnelson »

Just an idea - as a general rule getting a missfire when booting it can be fuel related. Clogged fuel filter, injector issue or fuel pump on the way out perhaps?
Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Re: Desperate help with misfire

Post by Sbsoulby »

Yeah possibly, I think it's the next place to start, with the cheapest as I'm fed up of spending already
markstevieandmads
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Location: Swindon, Wilts

Re: Desperate help with misfire

Post by markstevieandmads »

Coil. Check for cracks in the casing and take it off with the bracket and give both a good sand down as the coil earths through the bracket.
auzzam
Posts: 218
Joined: Fri Oct 16, 2015 11:20 pm
Location: London

Re: Desperate help with misfire

Post by auzzam »

markstevieandmads wrote:Coil. Check for cracks in the casing and take it off with the bracket and give both a good sand down as the coil earths through the bracket.


This :thumleft:
Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Re: Desperate help with misfire

Post by Sbsoulby »

Cheers. I've taken it off today and it's looking pretty rusty and also the outer casing is cracked, next part is to try remove these rusty screws so I can clean it up
Dale_V
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Re: Desperate help with misfire

Post by Dale_V »

if the casings cracked you need a new coil :thumleft:
abovetherim
Posts: 594
Joined: Wed Feb 16, 2011 8:49 pm
Location: Leicester

Re: Desperate help with misfire

Post by abovetherim »

As a short term fix you might get away with drying the coil out then sealing the cracks with rtv. This will give you time to source new one. You still need to clean up the bracket tho.

When I last swapped my coil I had to drill off the heads of the screws.
They were replaced with M4 by 15mm machine screws and copperslip
Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Re: Desperate help with misfire

Post by Sbsoulby »

Cheers, I took it apart and cleaned the bracket, the casing on the coil wasn't so great and the bit that sits on top of the bracket it pretty corroded so I've ordered another through tcp
Hopefully I'll have that on and it'll be the end of it, otherwise it's back to the drawing board
mr2magic
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Joined: Fri Apr 09, 2010 9:33 am
Location: Hannover, Germany

Re: Desperate help with misfire

Post by mr2magic »

Exactly how did you set the timing to 10 degress?
Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Re: Desperate help with misfire

Post by Sbsoulby »

With a timing gun, turning the cap
caldridge7
Posts: 235
Joined: Tue Sep 22, 2015 5:42 pm
Location: Spalding, linconshire

Re: Desperate help with misfire

Post by caldridge7 »

Forget all the above take it out for a drive get it to misfire etc and then pull over and open engine lid and check to see if the overflow coolant tank has shot coolant out onto the coil pack passenger side back corner.
Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Re: Desperate help with misfire

Post by Sbsoulby »

There's definitely not a coolent leak, I had it misfiring last night on the way to the unit to change my dodgy sump pan, and there was no evidence of any leak anywhere

I've got the ignition coil on order, hopefully be here tomorrow, there was a crack in the casing so I'm hoping it's arking out and causing the misfire, I'll soon find out I suppose
mr2magic
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Location: Hannover, Germany

Re: Desperate help with misfire

Post by mr2magic »

Ok. Is the static timing set correctly?
Dale_V
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Re: Desperate help with misfire

Post by Dale_V »

caldridge7 wrote:Forget all the above


No really dont forget all the above :roll:

The coil pack has a crack, its a known/common issue usually presenting the exact issues hes experiencing
Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Re: Desperate help with misfire

Post by Sbsoulby »

mr2magic wrote:Ok. Is the static timing set correctly?


I believe so, I didn't do it personally, I had a mechanic friend do it for me
mr2magic
Posts: 643
Joined: Fri Apr 09, 2010 9:33 am
Location: Hannover, Germany

Re: Desperate help with misfire

Post by mr2magic »

That might be something to check if changing the coil pack doesn't work out. Often enough people reference the wrong mark on the crank pulley and set timing based on balancing marks :wink:
Sbsoulby
Posts: 75
Joined: Mon May 15, 2017 10:19 am
Location: Lincolnshire

Re: Desperate help with misfire

Post by Sbsoulby »

Great news, ignition coil has cleared the misfire

Thanks for all the help, really appreciated, can finally drive the car now properly

I'll double check the timing again to make sure it's correct

Thanks again
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