Really high egts and lots of cold smoke..IP ?

[Matt Bachand]

Your talking about when you let off the pedal it "hesitates"(for lack of a better word) at around 900 rpm for a split second then drops down smoothly to base idle right? Mine's always done it. I'd figure it's normal, considering mine does it, and your burb does it.

I'd have to say thats only 'normal' for a tired pump.

When I did this test for Bill Heath he told me look for ANY fall-outs or stumbles.

I did it about 15 times and I have none.

This doesn't mean that pump wont last another 100,000mi ... especially well lubed with additive.

Have you done a VIN check at the dealer and have them give you a print out? I found out my IP/PMD was replaced under the warranty at around 44k miles.

 

[iamdave0887]

Your engine just drops right back to base idle(560-600 or so) when you let off the pedal like a DB2 setup? your sure? I think if you watch the tach you'll see what i'm talking about.

Every DS4 i've ever seen does the same thing mine and kenny's does, even my friends brand new DS4 on his 95. it's not a "hesitation" per se. It's a computer controlled drop in RPMs. The RPM will drop to ~900 then it's decent to base idle is slower, but perfectly smooth. It's not a "hang up" in any way.

It's like the computer brings the engine down from "high idle" when it doesn't need it. The DS4 does it slowly, where as the DB2 just drops it all at once.

I'll get a video of what i'm talking about. Although you may be able to see it in Kenny's video. Let me watch it again.

Edit: Start listening at 1:39 in Kenny's video he posted. You'll hear him rev the engine then the RPM drops back down around 1:48. You'll hear it hit the "high idle" mark of ~900 then the drop to base idle is slower. Thats what i'm talking about. It's not a hang up, it's the ECM controlling the IP down to idle.

Kenny, one thing i noticed is that when a DB2 blows smoke like that, it idles very rough and the smoke never goes away, unlike your truck where it sounds like it idles smooth and the white smoke is gone after a little bit. I wonder if the ECM can take up for IP issues somewhat(sort of masking any issues) where as the DB2 when it's out of spec that's it, game over.

I'm still curious about your gauge. I know i've got some weird electrical interference when it's really cold as the EGT gauge in my truck will jump up to ~600 sometimes, with key on, engine off, in the first glow plug cycle. I wonder if you've got something similar?

 

[buddy]

The computers have a controlled decent from cold idle to warm idle, for example 40rpm per 20 degrees of coolant temp. If you also have a high idle that will add to the variability of the cold idle. Cold idle also has much more advance to it, and not so much extra advance at high rpm when at cold idle. But its not like this if its already warm, it should drop to idle rpms in one drop.

 

[iamdave0887]

The computers have a controlled decent from cold idle to warm idle, for example 40rpm per 20 degrees of coolant temp. If you also have a high idle that will add to the variability of the cold idle. Cold idle also has much more advance to it, and not so much at high rpm it high when cold idle. But its not like this if its already warm, it should drop to idle rpms in one drop.

exactly. I just can't explain it very well. Thanks Buddy.

 

[Matt Bachand]

Gotcha, I thought you were referring to a hesitation along the rpm range, not from 900 downward. Touche.

I guess I read what I wanted to read, not what you wrote. Re-reading it, it was quite obvious.

 

[Acesneights1]

IP was done by PO last year. I started it this am , barely any smoke. Thing needs a Priest. The Pyro is not at all glitchy. Very consistent. I still think Buddy is onto something with the timing. Motor sounds way too loud to me cruisin along warmed up.

 

[96 OILBURNER]

Have you talked to Bill to see if he would send you a replacement to try?

 

[buddy]

I would just check what the measured timing actually is compared to the desired first, before asking to change the PCM which may be good the way it is. Check idle fuel rate which could be the problem. Then run a TDCO learn without messing with the accelerator. See if the TDCO value has changed.

 

[Acesneights1]

will do.

 

[Acesneights1]

Have you talked to Bill to see if he would send you a replacement to try?

Bill agrees something is wrong. he thinks the IP is was calibrated correctly. I guess sort of what you guys were saying about possible unintentional Optic Bump. Truck is very reponsive.

 

[Matt Bachand]

Bill agrees something is wrong. he thinks the IP is was calibrated correctly. I guess sort of what you guys were saying about possible unintentional Optic Bump. Truck is very reponsive.

Keep in mind you also have a 4:56 geared CUCV so saying 4.10 is throttle responsive is saying something...

Does it 'trailerhitch' at all with cruisecontrol due to the inert sensitivity?

 

[Acesneights1]

Trailer hitch ??

 

[Matt Bachand]

Trailer hitch ??

Adjusting its speed and you feel it every move. Like a little too much fuel on the speed adjustments causing a quick tug on the drivetrain.
I've always heard this was a downside of the optic bump. Throttle becomes way too sensitive. I assume it feels like having a trailer bouncing around a little back there, hence the name, which I didn't coin.

 

[Acesneights1]

Well, even plugged in last night (-15f) it still shook and smoked like crazy. it was knocking really really bad too. My burb started without incident, no smoke at all.