85 300d power loss - PeachParts Mercedes-Benz Forum

yelorsirhc · #1 01-08-2014, 08:12 PM

85 300d 240k. Winter hit hard here in the midwest. This car came out of Arkansas and I don't think it's glow plugs had been used very hard. Well we had temps around here of 0 and below so needless to say all my glow plugs went bad.
Relay and fuse were good. Before I changed the glow plugs I had changed both fuel filters, did a valve adj, changed the oil and filter. Car was running like a race car, good power and would scream down the interstate.
I parked the car and it sat for about 5 days before I got around to changing the glow plugs. I pulled the hard fuel lines off and replaced all the Glow plugs. Car started right up and new glow plugs worked great.
Drove the car around town no problem. Took the car on the interstate...big problem...Had hardly no acceleration getting on to the highway and would only do about 65 with my foot to the floor. Before I could run 100 no problem.
Came back in to town and floored it from a stop sign the engine got to about 3800 rpm and just stayed there it didnt shift until i let my foot off the gas. Going down the interstate it feels almost like I am pulling a 10k # trailer. I don't understand how pulling the hard injection lines and installing new glow plugs could cause this. I thought maybe I plugged up a fuel filter so to be on the safe side i replaced both pri and sec filters. No luck. I cracked all the injection lines with the car running just to see if maybe air was in the lines? No luck.
Checked the line from the manifold that controls the ALDA thought maybe I knocked it lose, it looks fine. I really don't understand how it could go from running like a race car to a dead dog just from pulling a few fuel lines and installing new glow plugs.
It really feels like it isn't getting enough fuel. In town if I floor it and keep it floored it will not shift just kind of stalls out at around 3800 until I let out of the gas pedal....Fuel looks very clean in the primary filter and I dont see any air bubbles.....Help?

vstech · #2 01-08-2014, 10:06 PM

I had to remove your colorful description of performance, this forum needs to be kept rated G.
thanks!

I also added returns at the end of your sentences because your HUGE block of text was hard to read.

as for the performance issue, I'd check the accelerator linkage, odds are good you assembled something wrong, or broke something. it's also possible you left something disconnected. possibly the Bowden cable? take a picture of the motor linkage side including the valve cover in the shot. then have someone step on the accelerator to the floor, and take another picture from above the IP so we can see where the throttle stops.

yelorsirhc · #3 01-09-2014, 12:04 AM

I didn't disassemble the throttle linkage to do the glow plugs...I did that about a month before when I did the valves. After reassembly it ran fine....problem didn't come up until now. Like I said the only thing I took apart to do the glow plugs was the injector hard lines. Thanks, I'm new to the forum. Will get you some pics tomorrow as it's pretty dark right now and I don't have an extra foot to help me out.

Zacharias · #4 01-09-2014, 12:36 AM

Doing the glowplugs is a relatively awkward job and it isn't unusual for something to be disturbed the process.

Have someone else sit in the car (engine off, obviously) and press down on the throttle pedal. Look to see if the linkage is actually travelling all the way or whether something is binding or catching.

Also check whether the large pivot bushing at the firewall is still in one piece. When that breaks you will have serious performance shortcomings (and it may have broken due to the weather and age, not connected to the work you did).

Also check that you don't have any interference from the floor mat with respect to pedal travel. You would not believe how many people have described similar symptoms and ended up finding that as the cause, especially in winter.

yelorsirhc · #5 01-09-2014, 01:01 AM

Quote:

Originally Posted by Zacharias

Doing the glowplugs is a relatively awkward job and it isn't unusual for something to be disturbed the process.

Have someone else sit in the car (engine off, obviously) and press down on the throttle pedal. Look to see if the linkage is actually travelling all the way or whether something is binding or catching.

Also check whether the large pivot bushing at the firewall is still in one piece. When that breaks you will have serious performance shortcomings (and it may have broken due to the weather and age, not connected to the work you did).

Also check that you don't have any interference from the floor mat with respect to pedal travel. You would not believe how many people have described similar symptoms and ended up finding that as the cause, especially in winter.

Yep, going to give this a try when I have an extra foot around. She was running so great too....Kind of disappointed now

. In town if i mash it to the ground it gets to about 38mph and 3900 rpm (I'm assuming 2nd gear?) and just stays there....refuses to shift until I let up on the pedal. Anyway here are a few pics of the linkage. See anything obviously wrong? Excuse the wetness from cracking all injector lines trying to bleed air. (Red hose with string around it is heater hose going to WVO tank tied off for the winter)

http://i39.photobucket.com/albums/e165/yelorsirhc/20140108_230728.jpg

Zacharias · #6 01-09-2014, 01:45 PM

Your linkages are 90 degrees off at the pivot for the cruise control box.

My guess is that they are hitting the blowby recirc vent spout (no idea what the correct term is) and/or the oil cap when they move and limiting travel of the entire linkage.

You don't need the second person to check that, just pull on the linkages toward you with the engine off and see how they move.

Sorry for the poor quality of the attached pics, done with my lousy old phone camera at lunchtime outside at work.

toomany MBZ · #7 01-09-2014, 02:57 PM

^ Yeppers, bind city.

cooljjay · #8 01-09-2014, 03:31 PM

check your throttle pivot mount..

yelorsirhc · #9 01-09-2014, 05:54 PM

Thanks everyone for the replies, but I found my problem.

As I suspected it was a lack of fuel.

The car has a WVO system and the inlet hose to the IP ran through a metal fuel heater. Over time the heat had broken down the inside of the rubber hose. When I took it off to do the glow plugs and pushed it back onto the heater it did what you see in the picture below. Also pictured is the inline fuel heater. To save any trouble I just bypassed the heater and went straight to the IP. She is back to screaming down the interstate.

I will investigate the linkage but I'm pretty sure that's the way I found it.

yelorsirhc · #10 01-09-2014, 06:14 PM

Got it turned around....thanks!

toomany MBZ · #11 01-09-2014, 07:04 PM

Glad you found the issue.

yelorsirhc · #12 01-09-2014, 10:20 PM

Yep sure did. The cc linkage wasn't hitting anything but I figured it should be fixed. Also when ever I set the CC it would speed up about 5 mph....I know why now

That inline fuel heater gets extremely hot. I thought it only got up to around 180* or so but infrared therm. says well over 300...Rubber hoses didn't like that I guess.