S4s rolling restoration project

[tomcattom]

Bit of a mixed bag of emotions for my 500th post on my restoration thread. Car was booked in for a new exhaust to be made by Hayward & Scott back earlier in the year and was dropped off to them a week ago last Saturday , however on my way round the northern stretch of the M25 to drop the car off I suddenly lost all boost . The car wasn't misfiring and no CEL light was observed, I simply had zero boost. I managed to get the car there safely without any further drama, because its still otherwise driving fine and able to keep up with the traffic.

We couldn't find any obvious reason for the loss of boost for the brief period I had to look at it when I dropped it off; hoses all looked okay, wastegate flap moves freely, the elephant trunk hose from the airbox hadn't delaminated and collapsed, so I was at a bit of a loss.

Fast forward to today. I collected the car and while loading the old exhaust parts into to wife's car several large chunks fell out of the old cat, so at that point we thought it might be a simple case of blocked exhaust and apt timing for a new exhaust.

Anyway, here are a few snaps. I've had a 3" system made with twin 3.5" inward rolled slash cut tailpipes and a 200 cell sports cat.

 

On the way home sadly the car still wasn't running right. The boost seems to have returned to some extent, but if I try to apply more than the merest amount of throttle it just starts coughing and spluttering, but oddly still no CEL light. As with the journey to Essex, the car was able to be driven back safely, but just seems to have lost its get up and go. As I backed the car into the garage when I got back the CEL light did then come on, so I'm hoping whatever error code has triggered that may reveal the problem. Either way I'll be investigating more thoroughly over the weekend.

Here is a brief video of what it sounds like with the sports cat fitted. I did get a decat made too, but that's currently sat in the boot. The small puffs of black smoke suggest I have a potential fueling issue, so I'm hoping that the new RC injectors I have may go some, if not all the way to solving the running issues 🤞

 

[Mysterae]

That exhaust looks lovely. Always toyed with making my SE dual exhaust and despite having a decat pipe already fitted, putting a cat back in.

Hope you find the reason for the problems.

[Bibs]

Last time I had those symptoms, it was a rubber elbow on the MAP pipe that was leaking. 

[tomcattom]

Thanks @Bibs. I'll take a quick look at the MAP pipework today. They did some other work for me on the car (photos to follow another day) and could well have disturbed that thin tube in the process, so it could be that.

[Giniw]

Just to be sure, maybe you could try to reset the ECU since it may have learned bad infos when your cat was blocked?

[tomcattom]

Well done Dr @Bibs, diagnosed it in one.

The pipe from the MAP sensor had been pulled off the barb on the engine and was found dangling down in the engine bay. Must have got distubed by accident while they were working in there. I plugged it back in and immediately the car is running so much better. I haven't properly driven it yet, but just based on driving it in and out of the garage the throttle response and idle is much improved 😌

[tomcattom]

2 hours ago, Giniw said:

Just to be sure, maybe you could try to reset the ECU since it may have learned bad infos when your cat was blocked?

Hoping that wont be needed now based on the MAP pipe discovery. But we'll see after a run out later this evening to test.

[drdoom]

Plugged cat will certainly kill most of a car's power, likely both diags will turn out correct.

[cweeden]

You might want to hold on tight, it might be a touch more lively if the cat was blocked. 🙂 

[tomcattom]

7 minutes ago, drdoom said:

Plugged cat will certainly kill most of a car's power, likely both diags will turn out correct.

There is a stretch of the M25 around Potters Bar/Waltham cross that is surfaced in concrete and it's a bit rough - or at least it feels like it in an Esprit - and it was around there that I was first aware I'd lost boost as I pulled out to overtake a car on one of the uphill stretches. My best guess is the rough surface was enough to shake an already fragile chunk of the cat innards free and block the exhaust.

1 minute ago, cweeden said:

You might want to hold on tight, it might be a touch more lively if the cat was blocked. 🙂 

Indeed. I'm hoping all the time I spent before it went in for the exhaust trying to set the actuator wasn't wasted and have to go through all that again 🙄 I'll prepare for a possible while knuckle ride when I enter the national speed limit road for the first time later.

[tomcattom]

Well that drive was... errr... exciting. Car is running fine again; no misfire and boost all accounted for and then some. You were right about it being more lively @cweeden!

Seems the cat was already partially blocked for some time before the exhaust was done because my adjustments of the wastegate actuator are now well off. I was seeing 0.91bar of boost on only ~50% throttle, so I think I need to back out my previous adjustments 😆

[tomcattom]

After several shakedown runs over the past few days to tweak the actuator and tame the boost I'm getting nearer my target. I'm not getting full boost on 50% throttle any more, I'm now down to 0.83bar at 100%, still a little way off my target of of 0.65bar, but edging nearer.

 

I went out for a run this afternoon and saw plenty of other nice machinery on my travels; a BRG series one E-type, a lovely metallic mid-blue late seventies/early eighties vintage Aston Martin V8 Vantage and a TVR Tamora. Got plenty of looks in the Esprit and some appreciation from some pedestrians while I was stopped at some traffic lights, so obviously gave them a show of the lights 😁

When I got back I recorded another video of the exhaust since the previous one was recorded before the MAP was plugged back in. Sound much better now it's running right. Apologies for the poor angle of the footage; little'un was asleep so couldn't get to my tripod without disturbing her.

[Giniw]

21 hours ago, tomcattom said:

my target of of 0.65bar,

If I remember well the max boost of the S4s is 1 bar without the overboost. I am not sure how you are trying to adjust the actuator? It should be done with a pressure gauge and a calliper (the measuring one, not the braking one :D) and that's about it?

[tomcattom]

Section EF12 in the 1993 onwards manual states that 0.65bar should be set on the actuator and then solenoid gives you the 0.35bar extra to get your to magic 1bar number, based on the tests I conducted with and without the bleed solenoid connected and no other changes. This all assumes that I'm following the correct instructions for an S4s....

I did originally set the wastegate with a DTI gauge as per the book @Giniw, but I wasn't able to get consistent measurements using that method so wasn't totally convinced it was right from the off. After initally running the car I found my boost was only 75% of where it should be, so I switched to trial and error measurement/adjustment with Espritmon. It has since transpired that my old exhaust must have been partially blocked unbeknownst to me long before the new exhaust was fitted and the trial and error adjustments I had made were based on flawed information due to a restricted exhaust hurting the performance of the car.

It's a right ballache of a job to get the boot floor back out just to reset it all with a DTI again, so I'm just working back the other way with trial and error using Espritmon again until I hit 0.65bar and then I'll wire the wastegate solenoid back in and hopefully all will be right in the world again 🤞

[tomcattom]

At last, I have got my actuator set up how it should be. I'm now at 0.69bar (approx) of boost at 100% throttle. I won't be able to reach down to 0.65bar as per the book because I'm running a Forge wastegate actuator and the "stock" spring they supply is 0.7bar. In the end my manual setup with the DTI wasn't too far off from the start, I was only one turn of rod off where it needed to be. Moral of the story, check you exhaust isn't partially blocked first 🙄

Once the engine bay has cooled down I'll go back out and hook up the wastegate solenoid again and verify that I'm now seeing full boost under the right conditions.

[tomcattom]

Last night I reinstalled the wastegate actuator solenoid to begin testing with that back in play. After doing that I decided to start giving the interior a much needed good clean for the first time since I've owned it - the wife keeps complaining I smell of "car" after I come back from a run in it. To be fair to her there is quite a strong smell of engine fumes absorbed into the materials, probably as a result of the long running fuel leak issues the car had before I owned it.

I gave the seats a clean and condition with Gliptone Liquid Leather. This shot shows before cleaning (right half) and after (left). They were quite greasy it would seem.

All finished with conditioner applied.

 

The headlining had quite a lot of ingrained stains, general discolouration and signs of mould that's been there since I've had the car. I tackled this with a mild concetration of all purpose cleaner sprayed on and then gently worked in with a damp microfibre cloth. What came out of the fabric into the cloth was disgusting

Roof panel before

And after - not perfect but a vast improvment.

Back in place showing the rest of the headlining cleaned up. It's not as clean as I can potentially get it, but it's a major step up for a couple of hours work. I'll tackle it again more thoroughly in the not too distant future.

 

Then this morning I went out for a drive to go to the Cars & Coffee meet at Bremont's "Wing" manufacturing HQ in Henley. This is the first meet I've actually taken the car to. I got a great parking spot and it seemed to get a lot of attention given its spot

[Chillidoggy]

47 minutes ago, tomcattom said:

Last night I reinstalled the wastegate actuator solenoid to begin testing with that back in play. After doing that I decided to start giving the interior a much needed good clean for the first time since I've owned it - the wife keeps complaining I smell of "car" after I come back from a run in it. To be fair to her there is quite a strong smell of engine fumes absorbed into the materials, probably as a result of the long running fuel leak issues the car had before I owned it.

I gave the seats a clean and condition with Gliptone Liquid Leather. This shot shows before cleaning (right half) and after (left). They were quite greasy it would seem.

All finished with conditioner applied.

 

The headlining had quite a lot of ingrained stains, general discolouration and signs of mould that's been there since I've had the car. I tackled this with a mild concetration of all purpose cleaner sprayed on and then gently worked in with a damp microfibre cloth. What came out of the fabric into the cloth was disgusting

Roof panel before

And after - not perfect but a vast improvment.

Back in place showing the rest of the headlining cleaned up. It's not as clean as I can potentially get it, but it's a major step up for a couple of hours work. I'll tackle it again more thoroughly in the not too distant future.

 

Then this morning I went out for a drive to go to the Cars & Coffee meet at Bremont's "Wing" manufacturing HQ in Henley. This is the first meet I've actually taken the car to. I got a great parking spot and it seemed to get a lot of attention given its spot

Hope you were wearing a Bremont!

[tomcattom]

I wish @Chillidoggy!

Sadly all a bit more than I can currently justify the expense of given we're still trying to finish the house. Plus I am running an Esprit too 😆

[drdoom]

Lovely angle, that shot of the car with Land Rover in the background. It's true the smell of petrol is enormously pungent, good job getting the interior freshened up.

Cheers

[tomcattom]

From what I overheard, I believe that Land Rover belongs to one of the Bremont founders, not sure which of the brothers though.

[Chillidoggy]

28 minutes ago, tomcattom said:

From what I overheard, I believe that Land Rover belongs to one of the Bremont founders, not sure which of the brothers though.

I met Giles English at a Bremont event a while ago. He’s a charming guy, and related the intriguing story of how he and his brother Nick decided on Bremont as the company name. I’m fairly sure that at that time Giles was driving a Porsche, and Nick a Jaaaag. 

[tomcattom]

Giles was definitely milling about and speaking to folk. I didn't notice Nick though, but he may have been there and I simply didn't see him.

[stephenwhyte]

Looking fantastic Tom! Great to see all the hard work has paid off…..you’ve got a really beauty there now!👏🏻👏🏻😎

[Giniw]

Very nice!

Also beware of the general purpose cleaner, I have seen some carpet strangely discoloured on a used bit I once bought for the Elan. Maybe it was not related to a cleaner at all, but ...?

Edited June 14, 2022 by Giniw

[tomcattom]

The cars and coffee meets are getting more and more common. There are some during the week, typically in the evenings. Never been to a weekday one myself, they're never close enough for me to make it worth driving to them after work. This one was a Saturday morning and very close by, so was convenient