Running Sluggish

joebillhill · Post by **joebillhill** » Tue Jun 19, 2018 3:17 pm

So fiddling with the boost after replacing my cylinder head I had what seemed like a great setting. I did this before heading down from Wenatchee to Portland. Boosted quick, and was running 12 PSI with the pedal maybe halfway depressed. Peppy and the coolant temps were down even climbing hills (850-1000f pre turbo). However I adjusted it again thinking that I could get the same boost but with more of a range fueling with my pedal and decreasing the risk of going over 12PSI. It sucked! It seemed to just bog down during low rpm's and didn't really cruise that well at highway speed. I adjusted it again in Portland before my trip back North increasing the boost and it's been running hotter and sluggish. It gets up to 12 PSI easy enough but it just doesn't have much power. Weird to explain but it just feels like it's fighting to gain ground. Granted it was a hotter day and a little windier but highway temps (100kph were 850 as opposed to 650 earlier) and going up out of the Colombia Gorge I had to pull over as my temp gauge was reading 3/4. Midway back I adjusted boost compensator diaphragm back to stock. I marked it before adjusting and I think it was maybe 1/8th a turn up (at work, can't confirm)
I was going to try adjusting the wastegate again to maybe reach 12 PSI easier? I was also reading another post viewtopic.php?f=6&t=17862&hilit=sluggish that seemed like similar symptoms and was going to check the IP screen mentioned. My air filter is pretty new as is my fuel filter (~10-20k km for them)
Hopefully there is some crap in that little screen but are there any other thought of things to investigate.
Thanks in advance

Post by **Growlerbearnz** » Tue Jun 19, 2018 10:14 pm

I'm smiling, because I know this game all too well. "Just a little more... ah shit, what did I do".

Just to clarify:
All boost adjustments were made by changing the actuator rod length?

-Running great at 12psi with nice low EGTs.
-Decreased the boost a little.
-Runs like crap
-Increased boost a little
-Still runs badly, with increased EGTs, despite boost being back at 12psi
-Reset diaphragm, no change.

Check out that IP screen. I can't think of a reason why turning the boost down and then back up again would change how the engine runs. I'd avoid changing too many more settings until you've figured out what happened.

sk66 · Post by **sk66** » Wed Jun 20, 2018 6:33 am

Sounds more like a fuel issue to me. Changing the boost level w/o changing the fueling doesn't really do all that much (maybe a little cooler EGTs)... opening/dumping too early is a problem, but if it's making 12psi I don't think that's an issue.

I would check the IP screen mentioned, but I would be more suspect that it has something to do with the recent head replacement. I would verify the valve adjustments and ensure the timing hasn't jumped a tooth, things like that.

joebillhill · Post by **joebillhill** » Wed Jun 20, 2018 8:11 am

I'm smiling, because I know this game all too well. "Just a little more... ah shit, what did I do".

The old emotional roller coaster of Delica ownership...

-Running great at 12psi with nice low EGTs.
-Decreased the boost a little.
-Runs like crap
-Increased boost a little
-Still runs badly, with increased EGTs, despite boost being back at 12psi
-Reset diaphragm, no change.

Correct

I would check the IP screen mentioned, but I would be more suspect that it has something to do with the recent head replacement. I would verify the valve adjustments and ensure the timing hasn't jumped a tooth, things like that.

Alright, I'll check the screen and timing, the valves too as they may have altered during break in. If nothing then ill probably replace the fuel filter.

Would a vacuum leak contribute to this? When I camped on the way down, in the morning I found two mice on the batteries trying to hitchhike. Adorable little bastards. Maybe they nibbled on some tubes?

sk66 · Post by **sk66** » Wed Jun 20, 2018 8:32 am

joebillhill wrote:
I'm smiling, because I know this game all too well. "Just a little more... ah shit, what did I do".
Would a vacuum leak contribute to this?

I doubt it, but possibly. The IP has a boost actuated valve that allows more fuel in high boost situations (the full load diaphragm on top); if they ate that air line it could have an effect. Otherwise I don't see anything else... if they created a vacuum leak it might affect the brakes or cause the waste gate actuator to not open, but that wouldn't result in a loss of power/performance engine wise.

joebillhill · Post by **joebillhill** » Thu Jun 21, 2018 8:20 am

Pulled up the "hood" last night. Timing was on the marks, clearance on the valves was .25mm, and the screen on the back of the fuel filter looked free and clear of debris.
I took a look at the waste gate rod and it looks like it's near maxed out. I should have taken a picture but there were just a few threads showing on the bottom side. Driving into work today it didn't seem like it was boosting as quickly or easily as it should. It also just felt like it was lugging most of the time in 3rd and 4th gear.
I'll check the throttle adjustment but I remember adjusting that recently. Probably throw on a new fuel filter today too.

Post by **Growlerbearnz** » Thu Jun 21, 2018 3:15 pm

Does it still start easily?

Check the tube that goes from the turbo to the boost compensator (and, presumably, boost gauge)- if that's leaking, the compensator won't be adding enough fuel. It's close to the exhaust manifold, so it has a tough life. Check the IP diaphragm too- it might have a split, with the same result.

joebillhill · Post by **joebillhill** » Thu Jun 21, 2018 3:32 pm

Starts like a champ.
I'll check those tubes and I'll take a look at the diaphragm but it seems like it was in good shape when I was fiddling with it Sunday.

Lapprentis · Post by **Lapprentis** » Fri Jun 22, 2018 2:19 pm

I have seen the same problem and the engine had a new head too....Could it be related ? As for that screen: the was none on my Van: I did cleaned the part and the tinny hole on it but that was not the problem....All filters, fan, clutch fan and radiator were addressed too but with no results. I got some "cold down" after having tuned the Injection Pump but the engine is still a bit hight compare to "normal"...
Keep in touch !
Lapprentis

joebillhill · Post by **joebillhill** » Sat Jun 23, 2018 1:38 pm

Pretty strange huh Lapprentis? I just changed the air filter and it seems like it's doing a little better. Maybe a little faster spooling up but still bogs down at higher speeds. Fuel filter is next., and checking turbo hoses. Hopefully it doesn't come to IP work...

Post by **Growlerbearnz** » Sat Jun 23, 2018 5:55 pm

Do you still have the EGR valve? Maybe disconnect and plug the vacuum line from that temporarily- if it's opening at the wrong time it'll make the engine run badly.

joebillhill · Post by **joebillhill** » Sun Jun 24, 2018 5:17 pm

No, i deleted the egt a while ago. I feel like the issue has resolved itself though. After the new air filter and fuel filter it's running better. Took it up Steven's Pass yesterday and it was keeping cool and running 900-1000f. Albeit at ~60km because I was keeping it around 12 PSI (I need that intercooler!)
I might keep tweaking with settings (and start the whole process over again haha)
It does bog down petty quick in 4th on any incline, I don't know if that's normal or just mine. I feel like I've had numerous "baseline performance" feelings over the years.

Post by **Growlerbearnz** » Sun Jun 24, 2018 7:38 pm

joebillhill wrote: Albeit at ~60km because I was keeping it around 12 PSI

So it'll go over 12psi if you floor it? You need to adjust the wastegate some more (and start the whole process again! Fun!). If it's adjusted correctly, you shouldn't be able to make it go over 12psi (except maybe a short boost spike if you suddenly floor it). Obviously, being a mechanical system, the limit won't be absolutely precise- it'll change depending on ambient temperature etc.

joebillhill wrote:It does bog down petty quick in 4th on any incline, I don't know if that's normal or just mine.

It's normal, but it's not entirely mandatory. That you can keep it down to 900-1000f while climbing a hill suggests that you could use a little more fuel under boost. I think if you add enough extra fuel to hit 1100F at 12psi in 4th on a hill, you'll find it won't bog down quite so much. Turn the diaphragm so the offset cone moves towards the rear of the engine and see what happens. (You might need to adjust your idle speed after turning the diaphragm).

...add fuel after making sure you can't go over 12psi, of course. Get that sorted first.

joebillhill · Post by **joebillhill** » Mon Jun 25, 2018 8:19 am

Alright good to know. I'll crawl back under there and adjust the wastegate, hopefully without too many burns to the hands! Then move on to adjusting the diaphragm.
Just got around to pulling the dash off last night to zero out the tach. Did you pull the whole thing apart or just apply a little locktite to the needle to get it from jumping around?

Post by **Growlerbearnz** » Mon Jun 25, 2018 2:55 pm

I would adjust the wastegate and drive it around for a bit, confirm the 12psi over a couple of days, before adjusting the diaphragm. That way if anything goes weird you know what's caused it

Rev counter needle: I just used a tiny bit of loctite, applied with a pin. I really didn't want excess loctite making its way down the shaft and into the bearing...