Cummins 4BT & Diesel Conversions Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
Hi, <br>I'm restoring to health a 1998 4bt offroad P-pump engine, CPL 2109.  The engine had sat for a few years, and was making lots of black smoke when I would throttle up or down, and smoking constantly above 1500 rpm.  Changed oil and all filters, then sorted out a myriad of fuel issues including lots of algae in tank but this did not help with the smoke problem.  I just sent the injectors in for push test and am awaiting results.  Meanwhile I got out the vacuum pump and pressure tested the wastegate actuator.  It wouldn't move until about 20 psi, and my pressure tester only goes up to 30 psi, but at 30psi it would have only traveled 1/4" maybe.  It was holding pressure but soon started leaking down pretty fast and I'm sure the leak is in the actuator itself, will replace soon.  Looking further, I removed the wastegate cover on turbo and there was a lot of rust (looked like brown saltine crackers) under and around wastegate flap, which was stuck open 3/16" or so.  I chipped all this away but flap will not make contact with the base material and there is still a 3/32" gap.  How well does the wastegate flap need to seal?  Is this amount of travel normal for the actuator rod?  And could the wastegate being stuck open 3/16" have caused the smoke?  engine compression is good with no blowby.  Thanks, Daniel<br>
 

·
Registered
Joined
·
10,646 Posts
The wastegate flap should seal tightly. Being partially open will definitely cause smoke because you're not building enough boost to burn the fuel. Might need to take the housing off and give it a proper cleaning. Running rich also causes higher exhaust temperatures which you don't want. By 1500 RPM your exhaust should be totally clear. I assume your engine has a P3000 if it is a P Pump. The pump may need some cleaning as well. There should be an ID plate on the side of the pump to tell you which model it is. Having the injectors checked is a good thing.
 

·
Registered
Joined
·
982 Posts
Pressurizing the wastegate without drive pressure is a junk test. It doesn't account for the fact that manifold pressure forces opening the wastegate flap, if you have quarter inch opening at 30 PSI wastegate input then you don't have enough preload on the wastegate actuator spring.

I experienced same thing with an hx30 and ended up only building 5 lb of boost. I ignored wastegate actuator psi and set the preload to about an eighth of an inch which you got me in the ballpark...after that I tuned the wastegate to clamp the boost at the appropriate pressure for an hx30, which is about 25psi.

Take the turbo off clean the entire mechanism so that it seals and seats correctly adjust the pushrod length on your wastegate actuator for about an eighth of an inch preload and see how she runs. if you could actually give us boost numbers that would help.
 

·
Registered
Joined
·
10,646 Posts
Starnestree, one thing I just discovered. I have a parts manual for the CPL2109 and it is not a P pump engine. That one has the Bosch A pump which is another type of inline pump. Yours likely has the water/air aftercooler. Not sure about the power rating but probably in the 110 HP range. It definitely has the HX30W and the wastegate is set at 1.8 bar which is 26 PSI.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #7
Hi Goat and Char1355, Thanks so much for all your good advice. The Bosch place called and said the injectors are bad, so it should be a week or so to have them rebuilt. In the meantime I've ordered a replacement wastegate housing, which was surprisingly cheap. Will hook up a boost gauge this week also. Tabbed the KDP last night. Char, it is an A pump not a P pump as I previously stated. Part number on pump is 3928602, 116 HP, air to water aftercooled. I was unable to find a wastegate actuator for a hx30w for under $150, and you can of course get a whole new (china junk) turbo for that. Plenty of hx35w actuators in the $30 range, will these fit an hx30w? I know the bracket is different.. Daniel
 

·
Registered
Joined
·
13 Posts
Discussion Starter #9
Hi all,
Update: replaced the wastegate housing today and adjusted pushrod for 1/8" preload. Installed rebuilt injectors and started the engine.
It fired right up and runs great until about 1500 rpm, when the exhaust turns white and it sounds like she is missing of running rough. We checked a few things and hooked up a boost gauge, guess what?
5 bars of vacuum. That can't be right.
Hooked up a different gauge and no boost. Removed aftercooler and it's all clogged. Apparently the last owner didn't think that a clean air filter was important? So she is soaking in muriatic acid, fuming all over the place. It's pretty cool to watch. Hopefully this is all I'll need to do to have a great running engine!
 

·
Registered
Joined
·
10,646 Posts
Be careful using the muriatic acid which is actually an industrial grade of hydrochloric acid. You mentioned white smoke. That is not caused by a lack of air but a lack of heat. Lack of air would be black smoke indicating a rich fuel mixture. Might want to have the aftercooler pressure tested to be sure it isn't leaking coolant into the intake. Those things are like a radiator or heater core. They don't last forever and they aren't exactly cheap. Another issue that could cause the white smoke is low compression in one or more cylinders.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #12
Hi Char1355,
Not sure why the cause of the white smoke, but everything is put back together and the engine runs great with no smoke except when you first start it up, and a little as you increase throttle below 1500 rpm. The muriatic acid worked great and the aftercooler was pretty clogged which of course was hard to see. I soaked it 4 times (20-30m each) replacing with new acid each time and it ran clear the last time.
One thing I don't understand is that my boost gauge is only reading 5-7 psi at full throttle (2300 ish rpm) with wastegate boost line disconnected and boost gauge installed in its place. That seems low. Maybe the aftercooler is still a little clogged? The engine runs perfectly (no load on it yet though)
Thanks
Daniel
 
1 - 14 of 14 Posts
Top