1991 Pacific Blue SE - Nottm area (SOLD)

[Enright]

Still baffled. Yesterday I spent the whole evening on it.

The alternator and PAS belts are both now back on, and as far as I can see, everything is connected up as it should be.
I'm sure the fault is intake rather than exhaust related (unless it's EGR which is a combination of the 2).
I suspected an injector might be stuck open so I changed them all - no difference.
Earths all seem to be good (or at least attached).
The engine starts easily enough, and there are no fault codes. But it just revs like mad, and I suspect it's pretty lean because it quickly gets hot.

I tried taking the intake pipe off and putting my palm over the throttle body - damn thing nearly broke my fingers as it tried to pull my hand in!
But crucially - it kept running. Starving it of air at the intake should stall the engine, so I have to suspect an air leak either where the secondary throttle bodies join the cylinder head, or where the intake plenum joins the secondary throttle bodies.
Trying to block any of the vacuum ports on the plenum only caused revs to rise further as I disconnected them, and then fall to what they were previously.
The IAC operated fine too.
The only ports I didn't/couldn't try were the EGR and the vacuum to the servo.
I notice that the EGR is vacuum controlled, but I'm not sure if the vacuum opens or closes it - further investigation required.

Meanwhile I've had to take everything from the intake side off - again!
The gasket between the plenum and the secondary throttle assembly came off creased, but I'm not sure if that happened as I disturbed it.
I propose to clean and inspect everything (again), reassemble it in bright light (using gasket sealant at any mating surfaces), then give it another try.
If it still misbehaves I'll isolate and/or blank off every single port on the plenum (boost gauge, heater controls, EGR...) to eliminate them all from the equation, then progressively connect them back up again with it running until one causes it to rev as before.
If I can't get it to idle properly even having isolated everything, I'll find a way of using my compressor to pressurise the system to 1 bar, and then trace the hiss.

[Enright]

GOT IT!!!

I'm pretty sure that the creased gasket on the plenum was the problem. As I reassembled everything the second time, when I came to put the plenum back on there was so little room that the gasket caught against the stud nearest the IAC valve. It tried to fold back on itself, and had it done so, it would have created an excellent gap through which air could whistle but at the same time be very difficult to spot.

Anyway, it's sorted, and the car now runs beautifully. Tickover's still up by a couple of hundred RPM even with the idle screw wound right in, so there may be the tiniest leak elsewhere. But now I'm on the home stretch so can get on with the next few jobs.

What a relief! Time for a

[Enright]

Opinions please:

I've got a spare cam cover lying about. I'd previously stripped it, ground off the surpluss lugs and the "ISUZU -", then sprayed it blue and put it on my original Elan. However the paint started to flake, making it look worse than if I'd not bothered at all, so it had to come off.

Now I've nearly finished stripping it down again, but thought that the contrast of a high-temp red finish might look OK in the blue engine bay.
Can anybody recommend any decent finishes, possibly by providing an eBay link? I don't mind considering either gloss, matt or even that "crackle" type of look. I just don't want it to be polished or blingy!

[dapinky]

Neil,

As my 2p worth....... (which is probably actually worth £0.02 less than that)......

I painted one in red (for the red car!) about 7 years ago, and used red Plasticoat spray - nice colour match, and stood up to the job.

cover 3.JPG

On the Blue car, i went for a 'contrast' and did it in crackle black, with a CF plug cover (which I prefer).

carbon & cracle black cam cover.JPG

.....However, The red cover was on the engine I took out when I replaced it, so it is still here (and availlable to a good home)......

[Enright]

They both look good, but I prefer the red - in fact I think it looks great.
Right, that's what I'm doing, with a gloss black spark plug cover, and if it comes out as good as the picture above I'll be well pleased.
Thanks Dave.

Right, another question:
In attacking the plenum I seem to have created quite a bit of work for myself.
I'm getting quite good at taking the damn thing off and putting it back on again now...
Idle speed is very slightly high, and I think it's because I damaged a gasket or two and have a bit of an air leak.
I've done my best to seal it with whatever I had to hand at the time (Sikaflex, yes I know - what a butcher!) but that's not a long term solution and I ought to replace the inlet gaskets between the secondary throttle housing and the cylinder head, and the plenum and the secondary throttle housing.
Where could I find prices for these online nowadays, so I don't have to waste phone calls and peoples' time who I may need to rely on later?

[Artaban]

Neil,

Just in case you want to consider another colour for the cam cover. I couldn't decide on what colour to go with so in the end I decided to go with white as it appears to go with any colour car. I had it powder coated (£40) after the lugs and "Isuzu" had been ground off. I wanted to highlight the "Lotus" so had it covered in gold leaf by a local sign maker (not as expensive as it sounds) and picked up the gold plated bolts from ebay. I don't think it looks over the top but it does make the plenum chamber look tatty now. The turbo heat shield I had "Cermakrome" coated at Camcoat Performance Coatings in Warrington (£36).

Cam_Cover.jpg

Just need to get the plenum chamber out now and polished. Not looking forward to that one.

Andy

[dapinky]

Andy,

That looks good....

...as far as the plenum chamber goes, I have always managed to clean them up using aerosol Carb Cleaner - it's ideal for getting the oil/fuel/dirt deposits off, and doesn't damage any of the surrounding parts.

The best way I've found is to spray it on a small area, work it round with an old toothbrush (or if you don't have an old one, use the wifes' ).

That way you can get into all the casting marks and clean them up.

The solvent evaporates quite quickly (hence do a small area), and will leave it looking dirty and smeared.....

....but another quick squirt and mop it up with an old rag or paper towel whilst still liquid brings it up like new.

Repeat until it's as shiny as you want it

It only takes half an hour or so to do, but I expect you'll take longer than that as I usually carry on with cleaning, as once the aluminium is shiny, everything else looks bad, and I just keep going....

[Enright]

Thanks for the input Andy. It's all a matter of personal preference and the white isn't quite "me", but it may inspire others and any constructive contribution is welcome. I've said it before but the problem always is that the more you do the more you see, and the more you see the more you do! It's all down to when you cry "ENOUGH!"
Incidentally I think your turbo heat-shield , which can so often let the whole thing down, looks excellent.

The plenum's not too bad, but best if you have new gaskets to hand before you tackle re-assembly, or the air leaks can play havoc with the running. You may be lucky and it may all come apart without the original breaking into little pieces, in which case you might get away with some decent sealant. But if Sod and his law intervene...

[Artaban]

Thanks for the tips on cleaning Dave, I'll try the carb cleaner. I have used brake cleaner in the past (similar?) and it didn't come out all that bad its just that in comparison to a glowing white cam cover it looks dull. Anyway its great to see Neil bringing the car back to its former glory and it inspires me to tackle the next project on mine.
Andy

[daveiow]

Somewhat intrigued by the reasons for removing the Isuzu logo from the cam cover
Personal preferences aside Lotus has always had a (in)glorious reputation for using other manufacturers engines -
Austin, Coventry-Climax, Ford, Isuzu, Rover, Toyota as well as their own designs with various levels of success
In my world (agriculture) Isuzu has a very good reputation for its engineering with the Trooper and It's pick-ups and I for one have no qualms about its name on the engine
daveiow

[Enright]

Just personal preference - sometimes I simply CBA to have to explain to the uneducated, because it's more effort than it's worth to try to win 'em over!

[dapinky]

Dave,

the removal of the 'isuzu' was done for many reasons (and, yes, I suppose a bit of snobbery is one of them), but then a few of us went along to the factory and (amongst other things) bought up the last few cam covers that they had in stock - this was at the time a few years ago when quite a few people were having theirs painted, and the 'spare' ones were lent out on an 'exchange' basis so that people wouldn't need to be off the road whilst they had there own ones painted.

Anyway, amongst the covers we got, were 2 unlike anything seen before - the storeman couldn't say if it was a prototype, a special order or a modification - but it still had the OE labels (and same part numbers) on - However, it only has the ISUZU missing, and not the extra threaded lugs which don't do anything on our cars, so I would think it was more of a prototype than a modification, otherwise, why keep those bits?

Who knows????????

cam covers.jpg

Anyway, the bottom line is - removal of the word ISUZU has it's roots firmly in Lotus (even if I didn't know it at the time I did mine )

[daveiow]

Thanks for the explanation gentlemen.
It's the little snippets of history that you pick up from this community as well as the driving experience that make ownership of these cars so rewarding

[Enright]

But of course Dave's experience was at the forefront of my mind when I started out on this bit of the project - it had absolutely nothing to do with badge snobbery!!! <Cough, splutter >

[dapinky]

But of course Dave's experience was at the forefront of my mind when I started out on this bit of the project - it had absolutely nothing to do with badge snobbery!!! <Cough, splutter >

...even though we didn't go to Hethel until after we'd done the first few cam covers????? - That's bloody good ESP!!!!!

[Enright]

Woohoo - thanks for the paint recommendation Dave, that Plasticote is brilliant stuff!
There are a few occlusions (or at least I think that's what they're called), but overall I'm really pleased with the result.
With a couple more splurges over the bits that haven't covered quite so well, it will look just about perfect.
Here are a few pics of the prep work, mid-way through spraying, and the almost finished result.

[epipete]

Dave,

I have a good home for your Cam Cover, it'll look great with my new Samcos! Can we talk cash? Will it fit in your boot to Castle Combe tomorrow?

Pete

[Enright]

Here's the finished article:

[inkitin]

Very nice Neil. I like it.......................a lot!

[Enright]

Stop press: MoT passed! A few advisories which I'll add later, but we have a valid ticket!
Just a shame the Post Office will be shut on 1st June.