Problem Revisit Sluggy TD
 

my Wagon is sluggish, Always has been. It's rare for my RPM's to go over 2,000 unless I really push it. Freeway driving is mostly with the pedal to the floor Cruising 70. if I push it I can get the RPM's above 2,000 but thats far and few between...Idk if my Turbo is not kicking in or not. I certainly cant hear it when I have the car running like I can on the cummins and powerstroke albeit they are huge engines.. What should I be looking for on this? I noticed a small pass thru bolt with a hose on it near the bottom of the Turbo, and there's a Vac line to it to that branches off and goes to a metalic Round part near the front under the air cleaner. where it shoots to after that i dont know.

I'd guess your turbo ain't spooling. you need to open it up and make sure its not stuck. but then i've rarely worked on the older cars until i bought my td a few weeks back.

hmm... turbo problems suck... any other suggestions?

Is the linkage to the injection pump fully advancing with the pedal?

as barry123400 said. My Car had that problem. Tightend up the Linkages and it normalized.

I guess we are assuming there is no Fue Supply Restriction.

There could be another IP issue. If whey you step all the way down on the Pedal the Throttle arm on the IP is touching its stop. It could be that that stop needs to be adjusted. Part of what that Stop does is adjust the seed at wich the Governor would start to shutdown your Engine at high RPMs.

For below: Transmission in Park and the Parking Brake engaged.
After you are sure the Throttle is going all the way to the stop and with the Engine warmed up to operating temp (your Tachometer needs to be working) kind of a slow fast step on the accelerator and rev the Engine and see how high it will go on the Tach before the Governor limits it. You do not want to stay at that speel long just enough to note the speed. I do not know the exact spec except that it is between 4,000-5,000 rpm. Somewhere in that range the Govern should prevent you from going any more.

If does not reach at least 4,000 rpms I would adjust the Throttle lever Stop screw until I get that.

Note: This high no load setting is there to protect the Engine from over speeding. Your not going to go more than a few mph faster buy raising that speed beyond what the factory wants. But, if it is set too low you will not reach your normal Max speed.

For the most part ounce a Fuel Injection Pump leaves the Factory no one messes with the adjustment unless a specific problem shows up or somebody fools with the screw because they do not know what it is.

CORRECTION: These instructions are for a 123. I do not know if an 87 300TD has the mentioned port.
You could hook up a pressure gauge to your intake Manifold to see if your Turbo is boosting. Forced Induction on another Forum said words to this effect: Port for installing a Boost Gauge at rear of Intake manifold on the Air Filter Housing Side.
M10x1.0 port behind the air filter housing.

I believe max normal boost is 10-12 psi.

is the ALDA some way Connected to the turbo and it's signal is just not getting through?

I've checked the linkage between the pedal and the assembly, and when the pedal is floored so is the linkage.. I'll look at the turbo etc tomorrow and see if it spins or has abnormal play

You can take the elbow off the inlet to the turbo & watch it spin. If the car has an EGR valve, you may have a blocked inlet manifold.

Look into the archives for the alda circuit. The system that controls it seems to soot up over time on most these turbo cars. Almost a long term maintenance item.

There is a port on the intake manifold that reads the inside boost pressure. A feeder hose to an overboost device and then the hose goes on to control the alda on the injection pump. If this system obstructs and they will . You get boost pressure from the turbo. Yet the alda does not get the signal to increase fuel with the boost. So power is very low.

Always a mandatory check like the linkage was anytime an issue like yours rears it's head. Tons of information in the archives as it is such a common issue.

Where are you at in Florida? I am in ocala and would travel to help you out if you are not too far away. I have the same car.

Let's get a bottom line here:

When was the last time you change your fuel filters?

I am in tallahassee, a bit far from you. My filters were changed: Primary 3 months Pre: 3 months, Tank screen: 1 month. if you did want to come up I'm always glad to meet anyone, Especially see other wagons like mine

My car still has an EGR but the intake and Crossover system has been off several times with no blockages or build up noticed

There's a banjo bolt at the rear of the intake manifold that must be clear for the IP to deliver the proper amount of fuel under boost. If the bolt is clogged you'll get sluggish performance. Barry123400 mentioned the circuit but the bolt is a common bottleneck.

Does diesel Giant or someone have a good pictorial of the whole boost system?

I don't think you need your turbo to get the RPMs over 2000, the engine should be able to do that without it. This sounds more basic, like a fuel problem.

... the fuel system from front to back is new.. new fuel lines, new lift pump, bypassed fuel thermometer new injectors, hardlines are fine. new delivery Valve seals, new shut off actuator (stop lever thingus) there's no way it can be a fuel Delivery issue...the only thing leaking is the front crank seal and the vac pump seal

Pardon the stupid question, It hasnt got a trap ox has it?
My money is still on a sick turbo, does it blow black smoke under full throttle?
Has some one played with the IP controls, maybe adjusted the limiter?

Was there any improvement after the Filters were changed?

When you floor the Pedal does the Kick Down Swithch work drop you to a lower Gear?

no trapox, it has the mod that took it off, Changing the filters saw no improvement.. the kickdown switch works, I dont know if someone played with the IP or not I have nothing to compare it to

The engine will run much higher than 2k. He needs at least 3k to highway cruise at what he quotes.

The alda circuit on the injection pump isolated from the boost effect will present what feels like not only poor power but inferior acceleration. He should normally feel the transition point a little when the boost comes up and the alda starts letting more fuel in to burn. This starts to really occur at about 2k rpm.
Instead he is performance flat in that area and is struggling to get by it. What is painful is he has had this problem so long yet it is so common an issue. You can have boost till the cats come home. With inadaquate additional fuel from the alda control it is absolutly pointless to have it..

Now to be fair the issue could be something else. This area is pretty straightforward to check out and in many cases costs nothing to do. So it moves to the head of any list automatically. Many,many past owners have disposed of these cars for this particular issue.

I have been waiting to see if he will put it in park and setp on the pedal and see if he can (briefly, engne previously warmed up) actually get some highe rpms. He should be able to get up there around 4,000 rpms. And, the above test takes no eqipment if your Instrument Cluster has a working Tachometer.

Figured it out!
 

It's amazing really. it's always the simplest thing! So, Checking the boost Vac lines, I found this (see pic) I jumped the line with some spare line I had around... and needless to say... WOW. Now I can see why they say these vans can boogey! I am Curious, this line went to this little switch on the isolation panel between the fuse box, Brake servo line etc... what's the switch? I'll post a pic of my repair tomorrow. It's too dark now

Overboost protection device I believe.

Yeh...I had the issue too at one point but I guess it was not as bad. My 0-60 was 20+ seconds. Apprently it was common at Benz shops to bypass that Valve. It is the overboost protection valve. There are two simar valves, this was the one towards the inner compartment on the firewall correct?

Mine has been bypassed for 2 years with no problems. Apparently they clog up often...but who knows. And yeh, I had the same reaction when
mine was corrected "Oh, so this is what I've read about!!"

I still have to secure the patch line to the either end as it leaks a little. but it works and that makes me happy. the cloud of Crap that was blown out of the engine the time it kicked in was amazing. nice to know the engine can breathe better now

I'd like to revisit this topic a little more, tyler posted his 0-55 video and it's obvious my wagon is still lacking.. Is there a tutorial that can show me how to go through the connections for the boost signals to the turbo etc.. I'd hate to think my turbo has something wrong with it, I need to check if there's play in the turbine

Here's some notes to some questions that were asked

*There's very little smoke on hard acceleration, however there's some smoke With Rev in park

*Part of the Vac system had fallen apart and I repaired it, but it may still be leaking some, I'll check it and make a permanent repair,

I know there's some banjo fittings that need periodic cleaning, where are these fittings?

Sorry for the long winded post.....

There isn't a banjo fitting on the 603. It's more like a barb with a hose on it on the driver's side of the intake. It still has the overboost valve though, follow the hose.

Take your hose from the intake plenum fitting, run it directly to the ALDA. This should allow good acceleration once you build boost. Be sure that you can blow through the hose and into the plenum, if not then you need to clean the fitting on the plenum (intake).

Check the wastegate linkage on the turbo. I have seen two '87s with this linkage disconnected/loose, which allows all of the turbo's boost to be dumped, no boost and no boost enrichment. This linkage is hard to see, on top of the turbo between the compressor and turbine sections, a metal rod, probably need a mirror on a stick. This can be tested more easily with a boost / pressure gauge at the aforementioned intake plenum fitting. If no boost, check the linkage. If that is all good and still no boost, check that the turbo spins freely by removing the intake rubber boot, and be sure that your exhaust isn't restricted (at the trap-catylist is the usual spot).

If this is all good, check the fuel filters, fuel strainer in the tank, and fuel tank vent (by removing fuel cap). Some have run from a separate fuel source under the hood to ensure that fuel supply is not the problem.

Other than that it could be IP timing, but I'm running out of ideas.