Dedra turbo H630 XGN

[Kevinlincs]

Finally!
The issue with the massive misfire when coming on boost has been found.
A few items had been tampered with in its' past life, the fuel pressure regulator was one such thing as the tamper proof seal had been removed.
At the time I didn't think a lot of it when putting things back together, but now everything is in place they look a right pain to swap out, I found my spare regulator from the integrale and planned to swap it to eliminate it as I went along trying things.
Assuming things is often your downfall, something we learn but often forget.
I'd assumed that the regulator was there to stem fuel flow (clue in the name) so the more you wound the adjuster screw out the more fuel it would allow to flow through.
On checking the routing today to see if the swap to my spare would be semi possible without a lot of swearing (it wouldn't) it dawned on me, a check on the spares engine that I handily had sat nearby confirmed it, the regulator is after the injectors in the fuel flow so it's job isto restrict the fuel from leaving the injectors, not to just allow fuel to it. So the fuel is pressurised direct from the pump to the injectors and the regulator has the task of holding that pressure and restricting the flow away from the system, I'd got it the wrong way in my head!
Screwing the regulators adjuster most of the way in resulted in an instant solution, proper performance on boost at last, problem found! The fuel flow was enough for moving the car around and in steady driving but once on boost there wasn't enough fuel to the injectors! Doh, simple when you think of it.
I will take it to my local guy to properly set the fuell pressure, or maybe I'll get myself a gauge for future use, then it should all be well.

The Sunday ride out to the AGM is firmly on now.
Car needs a good clean and polish as it's been over a year since it was sprayed plus I recently bought some brand new OE front seat belts as mine are very dirty then we'll be all set. On the seatbelt thing I got caught out with an AlfaSud I'd restored years ago. First trip out and the Mrs was less than impressed to have a diagonal grey stripe across her blouse after a ride out! Best to not recreate that conversation   

[Kevinlincs]

Brought it home now to sort a few niggles, stopped for a quick snap at Belmont TV tower.

[DavidLaver]

Well done.  Great relief. 

Am hoping with the interior the quality will be remembered long after the price is forgotten, and you pile some happy miles on over the summer.

[Rob]

The Dedra's looking good Kev  . Fairplay for diagnosing that misfire when on boost. Not an easy one to trace. My Delta's recently started doing something very similar but my local mechanic seems to think it's the crank position sensor but I'm not sure.

[Kevinlincs]

I'm not out of the woods yet Rob, the extra boost has caused further issue...update to follow I hope...desperately hoping it'll be fixed in time for the AGM..

For what it's worth I did have a similar but milder issue with the integrale and it was the crank sensor so don't rule it out, cheap enough to replace too, so worth a try.

[Rob]

Fair enough Kev, I'll try to keep an open mind  .

[rikardo]

I finally succumbed to getting the rear seat out of my grale version so that I could trace the rear-mounted electric aerial extension cable, as the cable itself fell apart in my hands when attempting to connect up the period Grundig radio/cassette I purchased some time ago . Jeez! I think the cable is OEM fitment as its coupled in with a loom running fore and aft that is so well "buried" in the car that any after-market car audio company would not have gone to so much trouble. A pity it broke really, as I will not be attempting such a job with the replacement cable, but I will make sure its well hidden!
So, having finally looked in much better detail into the rear passengers foot-well, it soon became obvious that something is under the rear seat, as why else would there be a removable cover? And then taking the rear seat out and the sound-deadening mat, there sits something that must be the ABS ECU, along with the 2 rear sensor connections (yellow housings).
Im glad I didnt get the runaround you had Kev!

[rikardo]

Cover removed

[rikardo]

Revealing this

[rikardo]

(viewed from other side)

[Kevinlincs]

The Dedra has been trying my patience to say the least.
It seems there was more than one issue to solve, even once the fuel pressure regulator was sorted the car wasn't that happy. Ran ok, well ran very powerfully if truth be told but only with partial throttle. Anything approaching full throttle just caused huge problems.
So much so that it started pinking just before the water temp shot up. Blown head gasket.

The last few weeks I've had the head off, skimmed again and for good measure sent the injectors away for testing and cleaning. Report came back that one had a terrible spray pattern and none were delivering the correct flow.
All were salvageable with an ultrasonic clean and strip down, new internal filters etc or whatever they do and the engine went back together.

Drove better but still not right, I'd all but given up on getting the car running well enough to make the AGM Sunday. I've consulted the manuals checking all I could, swapping some parts from my integrale all to no great effect. Nothing seemed to work, the car really didn't like being on boost but was happy as Larry otherwise.

This week the alternator failed on my daily driver Alfa Giulietta so I had to use the integrale for commuting to work. It struck me that it felt slower than the Dedra.
Convinced that there is a boost control problem I resolved to have one last try and solving it this afternoon.
Could it be that the turbo wastegate had seized despite it being a refurbished unit? I fired up my little compressor and used a blowgun to put a trickle of compressed air to the wastegate actuator, no movement. It was then it struck me, I'd already checked in the workshop manual for the orientation of the pipework and even double checked against the integrale, but I'd still attached the pipe to the wrong connection! Fitting some tubing to the other outlet and just a squirt from the airline and the wastegate moved smoothly. Surely not, I'd attached the pipework wrong and the wastegate actuator wasn't getting any signal to bleed boost off!! The poor car must have been getting huge boost pressure, no wonder it didn't like it and went like a scalded cat when it did go...

I've done 30 or so miles in it this evening and it's perfect, drives smoothly with the right amount of boost and is perfectly happy to have full throttle. Just how I remembered my old Dedra and similar but less extreme higher up the revs than the integrale, just how it should be.

I'll use it a bit this week just to be sure but I can't see why I won't be at the AGM Sunday now, really happy to have found the problem even if it was self inflicted. But at least I know the problem has been found rather than guessing or hoping, as long as no lasting damage was done then it'll be fine.

[fay66]

(viewed from other side)

Hi Kevin,
Hate to say it, but I told you so!

Brian
8227
Looking forward to seeing all your hard work, next Sunday.

[Kevinlincs]

(viewed from other side)

Hi Kevin,
Hate to say it, but I told you so!

Brian
8227
Looking forward to seeing all your hard work, next Sunday.

Yep, that's where it's supposed to be but on my car it's empty where that ecu is.

All water under the bridge now.
Used the car for going to work today, really nice and smooth and a huge improvement on refinement over the Delta despite them being just a year apart.

[fay66]

(viewed from other side)

Hi Kevin,
Hate to say it, but I told you so!

Brian
8227
Looking forward to seeing all your hard work, next Sunday.

Yep, that's where it's supposed to be but on my car it's empty where that ecu is.

All water under the bridge now.
Used the car for going to work today, really nice and smooth and a huge improvement on refinement over the Delta despite them being just a year apart.

Kevin just pleased you've sorted it

[DavidLaver]

"a huge improvement on refinement over the Delta"

Mrs L never liked the look of the Integrales, but when I drove one I realised I'd been spoilt by our Dedra Turbo.  Very fond memories of it.  Back end would bounce about from time to time and had to be careful not to cook the brakes but a lovely way to travel as a driver or passenger.