EGTs high, Truck Sluggish: IP banjo filter clogged

[Ralph in Winnipeg]

Truck has been a little sluggish since the temperature started getting into the single digits. I have a tank of 50/50 diesel and 10w30 in there now and expected it to be a little slow to warm up but I did not expect the EGTs to be higher than climbing a hill loaded. I checked the air filter and it's good. Could it be the fuel filter? I have about 8000 kms on this filter and I have run a variety of oils through it. I'd appreciate any thoughts. Ralph in Winnipeg.

[Growlerbearnz]

It sounds like your ignition timing* might be late. Is the engine a bit less rattly than usual? If your fuel ignites too late, it'll still burn but it'll be chasing the piston down the bore rather than pushing it (making less power), and it'll continue to burn as it exits the exhaust valve (leading to higher EGTs without necessarily making black smoke).

*Ignition timing- the point at which the fuel actually begins to burn, rather than the point at which it's injected. It's dependant on injection timing, temperature inside the cylinder, fuel flashpoint, and autoignition temperature.

In your case, the things that might delay ignition are:
Cold air temperatures
Injection timing being later due to viscosity or compressibility of the fuel.
A longer delay between injection and ignition due to the fuel's viscosity, flashpoint, or autoignition temperature.

I'd try switching back to 100% diesel and see if it resolves. If it does, and you want to continue burning engine oil, you're going to have to advance your injection timing to compensate. And then not use 100% diesel without retarding your injection timing again, though you might be able to find a compromise which gives enough power on oil but not too much preignition on diesel.

Of course I might be talking out of my arse, and it might just be a slipped tooth on the timing belt or a stuck advance plunger in the injection pump.

[Ralph in Winnipeg]

I understand what your saying about the delayed ignition and it makes sense. I was also driving into a stiff wind so that certainly contributed to the EGTs climbing. As a point of reference, on the highway under normal conditions, EGTs are about 300°C at 3000rpm. Climbing the small hills around Riding Mountain Park, I have hit 400°C. I hit 500°C yesterday on a flat highway unloaded.....Not crazy high but still higher than what I'm used to. Today with less wind I was at 300-400°C at 2800 rpm. I'm going to fill up with diesel from the gas station and dilute the 50/50 diesel and 10w30 mix and that should help....I hope!

[Growlerbearnz]

Are those pre-turbo or post-turbo EGTs? at 100kph I'm running about 550C (pre-turbo), but it'll do 650C all day if I'm towing the caravan. I try not to go above 750C. Then again, my engine is now tuned for low-end torque, so it's not really fair to compare it to a more conservatively tuned engine.

I'm interested in the results of your adding more diesel into the mix.

[Ralph in Winnipeg]

These are post turbo temps. The probe is in the blanking plate on the exhaust manifold. I'll keep you posted on the results. It is about 500 km round trip to my cabin and I'm going up tonight. I'll fill up about halfway, further thinning out the fuel.

I can save the oil for next summer but at $1 per liter I'm going to notice the difference in my bank account from my daily commute. On the other hand, I picked up two 200 liter barrels of diesel from a company that was using it in construction heaters but is moving locations. Free and there was half a drum of kerosene as well! After some filtering and mixing with oil into the tank it goes! Ralph in Winnipeg

[Growlerbearnz]

Apparently I'm not familiar with the Strada's exhaust setup. On a Delica the usual blanking plate (where the EGR system was removed) is pre-turbo. Post-turbo it's all dump pipe and exhaust, nowhere convenient to add an EGT probe without drilling/tapping into cast iron.

Still, if I had all the temperature probes I wanted, my dashboard would be all temperature gauges and I'd be constantly paranoid.

[Ralph in Winnipeg]

Well it's not the fuel. The 250 km trip to cabin was uneventful with a pretty heavy load and with the 50/50 oil mix diluted to about 25% oil the truck ran cooler, still sluggish.....On the way back, having filled up again so approximately 10% oil, super sluggish and higher temps, in the 500C range. Took it easy and puttered home. I'm going to change the fuel filter but thinking maybe the muffler has a collapsed baffle?? I was going to upgrade the muffler eventually to a full flow "cherry bomb" type so now might be the time. These are the 2 easy fixes, if these don't work, I'll have to go a little deeper.

[Growlerbearnz]

I'm kind of glad it's not the fuel- with all that cheap oil out there, it would be a shame if it wasn't usable!

At least you get a new exhaust and fuel filter out of this exercise. Looking forward to hearing what you find.

[Ralph in Winnipeg]

New fuel filter installed and old muffler cut off. New Cherry Bomb in place and truck still moves like a snail, EGTs went up accelerating in town - never seen that before. I think it may be "less rattly than usual" so I'll be checking the timing tomorrow and see if the belt has indeed skipped a tooth. Truck is 22 years old so should probably look at the belt anyway. Ralph in Winnipeg

[Ralph in Winnipeg]

Top 2 gears line up perfectly with the timing marks after rolling the truck in gear. BUT the bottom gear's timing mark is at 2° on the 0 to 10 scale thingy. There is a decal under the hood in Japanese that says 9° so am I 7° off? No wonder it's acting this way. Now to figure out how to advance the timing........after checking what it should be.....please chime in folks!

[Growlerbearnz]

All the marks should line up with their pointers when the crank pulley is at TDC / 0°. Something's not right. There's a decent post (with pictures) about how to check here: http://www.delica.ca/forum/viewtopic.php?f=94&t=17654

Just remember to *not* rotate the pump sprocket backwards any more than a quarter turn.

Ignore the 9° thing. That's for setting the injection timing which is done by rotating the injection pump, not by misaligning the sprockets. The sprockets must always align at 0°.

(Setting the injection timing is a nightmare, requiring a dial gauge and a special adapter. As long as you haven't rotated the injection pump your timing will be fine. Might be a good idea to mark the pump and engine plate though, just for future reference if you have to remove the pump for some reason))

[Ralph in Winnipeg]

Ok shall do! I found and bookmarked that post yesterday, so my OCD does have some positive benefits! I saw that 9 and figured maybe my timing is retarded and therefore the lack of power and high EGTs. I should be able to get to that tomorrow night, figures crossed that this is the solution. Ralph in Winnipeg.

[Growlerbearnz]

Though... it's just occurred to me that a single tooth slipping would result in a 14° offset. I wonder if your timing belt has stretched? I guess you'll find out when you take the timing cover off...

One other thing to check is the rockers. They can crack and cause all sorts of weird symptoms- before they break totally and destroy the engine.

[Ralph in Winnipeg]

The rockers! what? I thought I had this figured out! I'm thinking the belt stretched. The truck had 15k on it when I got it. 22 years old, did they drive it one year and the park it or less than 1000 a year for 22 years? I don't know but then I jump in and drive it 20, 000 km this summer.

[Ralph in Winnipeg]

Ok now we're getting to the nitty-gritty. I have the 2 top pulleys lined up with their marks and the timing belt is a little looser than the 4-5mm factory specs. The bottom pulley is off a bit but the belt is a little loose. I loosened the tensioner pulley and pushed it a bit and now all 3 pulleys are on the marks and the belt is tighter. Am I good to go? Is it possible/likely that the belt stretched and that put the timing a bit out of whack but now if it is tightened up and back to normal?