ukadamwest

ukadamwest

Well-Known Member
While i'm having fun with the classic and the elusive misfire, the P38 seems to have got jealous of the attention the classic is getting and so decided to throw a misfire.

New plugs all round, slightly cleaner, but nothing stellar..

I did a compression test while going through the plugs with the following results:

(8) - 5 Bar (7) - 5 Bar
(6) - 4.5 Bar* (5) - 4.5 Bar
(4) - 5 Bar (3) - 5 Bar
(2) - 5 Bar (1) - 5 Bar

* the compression tester air lead came off so potentially low reading.

The fault codes I'm getting are: P0300 Misfire
and
P0307 - misfire on cylinder 7

Faultmate is showing misfire on cyl 7 and zero on all others.

HT leads have not been changed since I got it...

i'm getting really pushed for time with a new job and new baby and two misfiring Range Rovers. I sincerely hope tht the readings from the compression test (done when stone cold) is not a HG.

I would appreciate any thoughts before I start pulling heads as i'm not going to get a chance to delve into it for about 3 weeks so the wife will have to drive it as is for the time being !
 
It's on a multipoint LPG system so of course the coil packs are completely inaccessible.

Keith Gott parts guy mentioned that as the coil packs are two spark a faulty coil pack would show across two cylinders with a misfire.. however.. if it a corroded lead at the coul pack that *would* result in one cylinder having a misfire.

If it's coil packs then I'll be happy.

Will UV dye help if it has a gasket leak?

I appreciate the compression test was low being on a cold engine however the readings were with 10%
 
I just had a thought last week I spent the grand sum of £8.00 on a USB inspection probe .. so if I hook that up to the laptopI'll be able to see the coil packs
 
Are you doing compression test correctly. Pressures are crap. You do compression tests with throttle wide open not shut.
 
ukadamwest said:
Will UV dye help if it has a gasket leak?
Click to expand...

Couple of members on here now have only picked up the head gasket leaking by putting UV dye in he coolant, run for a few days and then check the dipstick with a UV torch. Little glowing droplets!

Of course, it depends where the gasket has failed.
 
wammers said:
Are you doing compression test correctly. Pressures are crap. You do compression tests with throttle wide open not shut.
Click to expand...

This is rather good. I check every cylinder 3 times when I do it and take the average.

 
If compression is low on a cylinder and you do wet test and compression improves, it is rings. If it stays about the same, it is valves. Compressions should not vary more than 10% across all cylinders.
 
I had a miss on just 1 cylinder and it was the lead completely corroded away at the plug in end at the coil pack when I swopped them out I found a couple more on there out.
 
Update....

So with the Baptism out the way kast weekend and having some time to set aside.. I gave the P38 a proper compression test.. and found number 5 to be a bit low.. pulling the plugs showed number 7 the misfiring cyl plug to be squeaky clean.... it's either not been sparking or is being steam cleaned...

Now. I've known for over a year that te rocker cover gaskets need replacing as they have been seeping and have all ready to go. Rocker cover gaskets.. inlet manifold gaskets and valley gasket (it suprised me but no one has been into the engine before but inlet manifold bolts were very loose.. maybe about 15-20 NM of torque tight !)

So. I spent Friday and some of Saturday stripping it down to the valley gasket.... and now thinking... I'm all this way... I may as well do the head gaskets for the sake of a set of stretch bolts head gaskets and some ball ache with the heat shield bolts..

Now.. as a question... to pull the heads do I have to remove the exhaust manifolds or is there enough stand off with the manifold bolts removed ?

Also.. I'm wondering if I should do the camshaft too... while I'm at this point...
 
And the rigs,liners,mains big ends............. the list goes on. once you take the heads off you will check the bores, then its rings and so on... go on you know you want to
 
The car is neither use nor ornament if its not right. Go for it, its only nuts bolts and money. The job itself is not difficult and its not your daily runner isit?
 
I still have his V8 in the garage....now I have made some space after pulling the engine out the 110 and the lighter evenings are here, its time to see how it has stood over the winter and get it finished.

It was liberally covered in duck oil and Lucas assembly lube with rags stuffed in all the holes before it was moved from the workshop to the garage so hopefully it is still clean.
 
tarphenry said:
The car is neither use nor ornament if its not right. Go for it, its only nuts bolts and money. The job itself is not difficult and its not your daily runner isit?
Click to expand...

Well it was the daily runner.. the Wife using it now have a baby.. so she's got my other car till the P38 is good again and I'll be using her mx5
 
Saint.V8 said:
I still have his V8 in the garage....now I have made some space after pulling the engine out the 110 and the lighter evenings are here, its time to see how it has stood over the winter and get it finished.

It was liberally covered in duck oil and Lucas assembly lube with rags stuffed in all the holes before it was moved from the workshop to the garage so hopefully it is still clean.
Click to expand...
Ant.. I ended up selling the LSE... however I kept hold of the compomotive 5 spoke alloys that were on it in case they fit your Landy.. I think they will. They are yours
 
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