Doo · Jul 17, 2020

Only two sensors...

Well, while the new O2 sensors vastly improved the running....,they only did so one the 6 functioning cylinders

So, everything possible has been replaced, but still has the misfire.

So today, I started stripping down the top end in prepare for removing the head

However, I still haven't done a compression test, mostly because I can't find a compression tester

But while I was in there, I checked the injectors (turned them upside down on the rail and wired them in....PSHT PSHT PSHT etc) and all squirting beautifully. and removed the rocker cover to check in case a rocker had broken (NO!).

So looking awfully like it's the gasket blown between 1 & 3.

Good news is the engine was sourced from RPI which most likely means the liners are Top Hatted....which is great news

Bit pee'd off about the probable gasket though

I shall keep you appraised of the findings.

Henry_b · Jul 17, 2020

You're taking the top end apart without first doing a Compression test?

Have you had the plugs out?

RangeRoller dt · Jul 17, 2020

Have you not met doo before?
Not unusual for him you should see his wiring threads

Henry_b · Jul 18, 2020

Leak down test would be worth a go too,.

RangeRoller dt · Jul 18, 2020

by time he reads this will be in bits. Once he gets summat in his head...

I will sell it love....I just want to put it right first....skip to 10 years later

Henry_b · Jul 18, 2020

I noted in one of his threads a new CPS fixed the issue, now it has reappeared..

Unlikely to be the Headgasket,..

However being a rebuilt RPI unit it is bound to have some issues..

RangeRoller dt · Jul 18, 2020

There been few posts/threads like that. Every issue found seems okay for bit, he’s changed a lot and adapted even more.

Doo · Jul 18, 2020

Ha ha, funny buggers.... Thought it would have been obvious that I had tried all manner of everything INC plugs and whatnot.

I honestly thought the crank sensor had fixed it (many many red herrings).

When I said I stripped everything.... I wanted to check I hadn't wired up the coil pack wrong (you know how it is when a seed of doubt enters your mind...).

Everything checked out, but I broke a plastic LPG manifold so I couldn't put things back together anyway

To be absolutely clear, I checked EVERYTHING there was to have caused a misfire (NEW cats, O2 sensors, plugs leads, coils, Crank Sensor, and so on).

THEN, I checked rockers, rocker shafts, valve springs, injectors and so on... I ONLY have the compression's to check "before" I remove the cylinder head on the left bank (which is showing misfire cylinders 1 & 3).

I have been through every single thing which flagged up (red herring) issues that could have possibly caused a misfire. The CS and O2 sensors, while "were" actually damaged (likely when the cats died), they STILL didn't fix the misfire which has been masked by the aforementioned issues on this POS car made by Twatty Trev and idiotic Ian.

So while I haven't "yet" undone the head, I am fully expecting it to come off seeing as how I have exhausted every single avenue of the probable cause of the damn misfire. The last straw will indeed be the compression test...

But while everything is apart, I plan to have the inlet valley manifold and both rockers to come off and get vapour blasted if it's cheap enough. At least that way the new owner will see the car has been picked clean and is amazingly shiny

Henry_b · Jul 18, 2020

No harm in ripping it apart..

The only RPI engine i've dealt with had a knock on arrival, once taken apart I found a cracked rocker pedistal, thanks to them only shimming 3 out of 4 pedistals!!

It also leaked like a sieve

V8developments are the only people i'd give my cash to..

Wazzajnr · Jul 18, 2020

Don't the rv8s wear cam lobes?
Maybe that's source of your misfire.
Might be worth checking valve lift on offending cylinders.

brianp38dse · Jul 18, 2020

Yes many a cam has been found to be well worn, made of chocolate like the td6 gearboxes
Mozz Smith on here went through a couple of engine rebuilds due to cams wear turned out oil way was blocked and starving a couple of lobes.
check lift with a DTI gauge that will ether confirm or rule out.

Doo · Jul 18, 2020

I know about cams on these engines. However , it has 22,000 miles on it and has had a total of five oil changes (the first being when it was installed and four since I've owned it) so I'm really hoping that's not the cas . I have the rocker cover off and the rockers seem to be moving fine ...

Henry_b · Jul 18, 2020

The Cams wear rapidly on the RV8 thanks to the wrong Oil being used, many will blame the engine

A 10w50 or 60 or a good quality 20w50 will extend the life of the Cam and the rest of the engine..

10w40 isn't the right oil, i've known some use a 5w30

Doo · Jul 18, 2020

I've always used 10W 50 fully synthetic because it was originally recommended. This engine doesn't burn oil and barely drips any

I did wonder if the cam was dead, but hope it isn't...

Henry_b · Jul 18, 2020

Doo said:
I've always used 10W 50 fully synthetic because it was originally recommended. This engine doesn't burn oil and barely drips any

I did wonder if the cam was dead, but hope it isn't...

I'd be wary The people that built your engine think 5mm of endfloat on the cam is acceptable, thats another story!!

most of what they say doesn't tally,

A load of cockends the lot of em.

Doo · Jul 18, 2020

Well, the compression test shows 1 & 3 cylinders are at around 30psi

So I think that rules out cam wear. But it's either burned valves or gasket burned between cylinders...

Just great. It "knows" I plan to sell....bastard

tomcat59alan · Jul 18, 2020

Doo said:
Well, the compression test shows 1 & 3 cylinders are at around 30psi

So I think that rules out cam wear. But it's either burned valves or gasket burned between cylinders...

Just great. It "knows" I plan to sell....bastard

Get the gasket / valves done, you'll fall in love with it again.

Doo · Jul 18, 2020

tomcat59alan said:
Get the gasket / valves done, you'll fall in love with it again.

Not allowed to fall in love with her again coz the other "her" hates everything about this car

tomcat59alan · Jul 18, 2020

Doo said:
Not allowed to fall in love with her again coz the other "her" hates everything about this car

Ooo,what a choice,Rangie or silent dinners, no contest.

Henry_b · Jul 18, 2020

A blow between cylinders more than likely.

on a 20k engine, typical RPI unit

Take the heads off and replace the gaskets.

did you do a wet test just for shíts and giggles?

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