Integrator value very low! Ideas?

[Vulcan Grey]

Reason that I thought about the MAP, is that it reminded me of when my friend swapped his MAP for a 3bar sensor and didn't tell me. Then he calls me to come look at his car that wasn't running well. It would idle ok, kinda lopey, but it would not run with any load at all.

So we tried looking at the spark, and the fuel, even removed all 4 injectors to place paper towels under them in order to make sure they were all firing. Cranked the car a bit and IT RAN!!! And it kept running, it actually idled better without the injectors... Then we remembered the secondaries They hadn't crossed our minds because we thought that they shouldn't fire at all until 4800+ rpm and higher TPS values... So then he tells me about the MAP sensor... Turns out the incorrect MAP sensor values were causing the injectors to fire too much, and the car was choking on fuel!

[SteveSmith]

Travis - you asked earlier for a Freescan log. Here you go: http://lexi.mantaur....Run20120513.csv

This was taken back in May.

My notes to Sparky at the time were as follows:

"Finally managed to find a bit of time and some sunny weather yesterday to take the car out for a logged run.

As expected, it drove like a dogs dinner, coughing and spluttering and backfiring in the 2400 to 3200 RPM range under light to medium load.

This is the EXACT behaviour I have always known since I bought the car and makes driving it very unpleasurable !!

Things of note are:

1 - The warm up cycle is still a great improvement since you adjusted the minimum air rate screw - idle is pretty good and it doesn't bog down all the time its in Open Loop.

2 - As soon as it switches to Closed Loop, things start going wrong including the above described issue of holding the throttle steady (whilst stationary) and after a couple of seconds the revs drop dramatically and it backfires and then picks up again and repeats this cycle. The CEL then comes on, reporting the Code 24 as previously described.

3 - At the end of the run (and as previously noted), the engine tends to idle very high (1500rpm ish) despite the desired idle clearly showing 987rpm."

Edited August 14, 2012 by SteveSmith

[Sparky]

Steve, tried to replicate code 24 before I took it apart, and it just wouldn't happen. That could perhaps be a MAP issue after all.

I know I asked you this before, but just checking: do you have more detail on what others have tried?

[SteveSmith]

The only specialist / dealer who has looked at it over the last 8 years who made ANY kind of sensible comment was that they removed the crank sensor, cleaned it up and put it back in again (whilst also doing a C service) and when they started it up and ran it, it was fine. But, as I've said before, they'd also fiddled with a lot of other stuff doing the C service so its anybody's guess what temporarily made it run OK.

My local main dealer told me that I needed to give the car a good blast to clear the carbs out... Needless to say, they won't be touching my car again

[Vulcan Grey]

Looking at your O2 and your BLM vs BLM cell, the car is definitely running very rich.

Nothing else stands out... MAP signal looks ok, though I would still try swapping to a known good MAP sensor.

Your injector duty cycle is very low, so the ECU is trying to throttle back the fuel, but it is still rich. You wastegate duty cycle also shows that it is opening pretty early, may want to check adjustment there.

Your TPS never goes above 76%. I'm sure Sparky will adjust that when he puts the manifold back together.

Crank Sensor seems ok, but double check the wiring for an intermittent...

Oh, and you didn't use 5th gear, and boost never went to max, but that is understandable since you are having this problem.

IAC was a little high, but you said this was before Sparky set that?

If you really are running that rich, and the O2 isn't suspect, then I would be looking for leaking injectors that are just dumping too much fuel, or possibly secondaries that are running all the time rather than just at high boost, high TPS conditions.

[SteveSmith]

Thanks for checking over the log Travis. I'm sure Sparky will take what he needs from your findings.

The reason I only hit 76% TPS and didn't reach full boost or fifth gear was that it was a warm Spring weekend and, because I live right by the sea, the traffic becomes unbearable at the first sign of any sun!!! And as I was nervous about taking the car too far and risk getting stuck, I decided to do my best on the busy local roads...

Thanks again all for your help so far. Possible leaky injectors and wastegate maladjusted sounds plausible to me but what do I know... I'm just the guy who's desperate to drive a healthy car

[Sparky]

Still waiting for gaskets - once they've arrived I'll throw her back together, check fuel pressure, then test-drive. Then MAP change, then maybe some injector shenanigans. Then some kind of ritual sacrifice. This one has me stumped!

[SteveSmith]

This one has me stumped!

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO..........

Don't say that

[SteveSmith]

Then some kind of ritual sacrifice.

Its all gone very quiet....

[Sparky]

Gaskets arrived, throttle bodies cleaned/adjusted and everything back together again. It runs, but still rough. All injectors show correct resistance, no evidence of any kind of inlet leak. MAP removed at the moment for a swap, but I suspect it's fine.

Didn't have time to drive or Freescan last night, so that'll be today. I may be keeping hold of this for a few more days!

[pete]

sue said its obvious SOMEONE HAS LEFT THE CHOKE OUT

[Vulcan Grey]

Sparky, record data when it is running rough next chance you get. I like to see from cold to warm just idling, and then also a drive (if possible) through all gears, throttle range and boost.

If not the MAP, can you swap injectors?

[Sparky]

Travis, you're gonna love this!

Having swapped EVERYTHING possible between my motor and Steve's over the last 36 hours, I finally found the problem(s). First, it wasn't doing a great job maintaining fuel pressure, and in fact I found every injector leaking slightly. Strange. Changed to my rail and got BLM up to around 115. Fantastic, almost sorted.

Nope. I was getting this value with the chargecooler dismounted. when I reattached the chargecooler, BLM dropped by around 25 instantly. Finally found that the turbo, with engine at idle, is pumping huge amounts of very hot air into the chargecooler. This is definitely exhaust gas, so the combination of leaky injectors and recirculating unburnt fuel is sending the ECU off the rails. Checked the compressor side of the turbo - turbine is quite chewed up. Also it's spinning really fast at idle.

Spoke with Steve, and 2 things are significant: there is a bill for a turbo rebuild just before he bought the car, and Steve found no air filter fitted. No idea how long it'd been running like that. It could explain the state of the turbine and the leaky injectors, but I'm intrigued about the turbo. It feels the same as putting your hand over the tailpipe.

[Trevsked]

Looking forward to seeing the turbo off the cars as I still can't u derstand how that amount of hot air is being fed on idle, or why it's so hot. Very strange. Come on Steve, time to look behind the sofa for that £2k you dropped out of your pocket.

Trevor.

[SteveSmith]

Believe me Trev, I've begun the search behind the sofa, under the floorboards, in the loft etc etc

I think its fair to say I have very mixed emotions about this news.

On the one hand, I'm elated that the problem has been identified and can now be fixed and I can now hopefully drive what is a beautiful car. On the other hand, because of a numbskull DPO, I'm discovering a deep resistance from my wife to allowing the fairly large expenditure on the car just to satisfy my 'whim'...

She'll come round, but I won't be allowed to forget it...

[sailorbob]

You may need to check the MAT sensor, the datalog above doesn't indicate excessive air charge temperatures.

[internets]

Sparky posting here! Yes had noticed that but the wiring on the MAT is shorting out !

[Vulcan Grey]

Sparky,

Hmmm, don't see how any exhaust gasses could get through the turbo, no matter how damaged? Intake temps on a non-intercooled engine should get up to about 214F easily (say on a 90F day) with boost. An NA engine would probably bee around 140F on the same day, and the intercooler on the Esprit should bring that down to almost 95F.

If Steve's compressor were damaged and not pumping efficiently, then I could see having temps even higher.

[SteveSmith]

Having given this some more thought, I'm even more confused than I was before...

When I bought the car, the impellor in the chargecooler pump was clearly shot as the chargecooler was hot to the touch after a run and Freescan showed much higher than normal temps. However, when I fitted an electric pump, the chargecooler was (and still is) cool to the touch after a spirited run and Freescan concurred with my findings by showing more than acceptable ambient temps. I'm sure I have some Freescan logs somewhere from 8 years ago showing the before and after and nothing has changed since then...

Also, I've tried to research the phenomenon of exhaust gases getting into the intake due to a failed turbo and I can't find a single reference to it.

So I'm still confused, especially as you tested your rail/injectors which ran well until you reconnected the chargecooler

[Vulcan Grey]

The MAT data that you posted on Page 2 does look low, since your start water temp was normal running temps and your MAT only got up to ~25C... That is freakishly low.

[Sparky]

As I said, MAT wiring is fritzed - the cables are bared and have definitely been shorting. I know this all sounds crazy, but five people have witnessed this - four of them knowledgeable Esprit owners - and are equally amazed.

[Sparky]

Thought I'd summarise this with everything known so far, as all most people will have to go on is the Freescan file.

Car has run strangely since just after Steve bought it. It lacked an air filter. There is an invoice for a turbo rebuild shortly before purchase (smoking gun?). Successive specialists have failed to remedy it. I've swapped everything possible over in terms of engine management, and still no joy. Freescan isn't exposing anything obvious, other than the mixture being very rich. Fuel pressure not maintained, regulator tested fine, injectors all leaking a little.

I started to get almost good BLM values with known good injectors, but only with the chargecooler disconnected. Chargecooler is not blocked. MAT should be disregarded due to dodgy wiring.

With engine at idle, putting one's hand over the turbo outlet demonstrates hot air moving under significant pressure (not necessarily exhaust, but it feels exactly the same, in terms of heat and flow, as tailpipe emissions from a hot engine). Compressor is turning VERY fast at idle, blades have a fair amount of damage.

I agree, I cannot think of any scenario that would produce this, but there it is, witnessed by five people. The only opinion at present is that the wrong exhaust turbine was used in the rebuild, but that still doesn't explain the hot air.

[SteveSmith]

I know I'm probably asking the obvious here but have you checked the turbo outlet on another car at idle ?? I'm way out of my depth technically now so have no idea what is 'normal'.

Also, I've been checking out all the historical photos I have of the car whilst in my ownership and found the following, taken in 2005, after I discovered that there was an air leak in the manifold to turbo joint:

http://lexi.mantaur.co.uk/images/turbo1.jpg

http://lexi.mantaur.co.uk/images/turbo2.jpg

http://lexi.mantaur.co.uk/images/turbo3.jpg

http://lexi.mantaur.co.uk/images/turbo4.jpg

Not sure if any of them are of any help in the diagnosing process - but, at the very least, it shows Sparky that the turbo has been detached from the manifold in fairly recent times so should come off again without too much bother !!

[Sparky]

Yup - it's ambient and zero flow as it should be. Had mine running next to it. Was gonna ask about the turbo to downpipe joint. Did you have a hard time sealing it? Looks like it's been seriously oversaturated. Taking that off tonight to pursue another possibility...

[SteveSmith]

I can't honestly remember having any problems sealing the turbo to downpipe joint other than the fact that the ring thats loose on the downpipe that is used to attach to the turbo is very bent rather than what I would expect to be flat. Following photo shows it well:

http://lexi.mantaur.co.uk/images/turbo5.jpg

Is it meant to be bent like that or has someone previously tightened up the bolts way too much and somehow bent it using some incredible force ?!?

Anyway, very curious to hear more about this other possibility you're pursuing tonight...