Not that I want to win races with it, but I thought these were faster than 75! It just seems to be really working hard at that speed. (Turns about 3500-4000rpm in top gear I think?)

Accelerates from a stop fine with your foot to the floor, but really starts slowing down at the top of third gear, but if you let off and make it shift to 4th sooner, it hits the boost/torque spot and is better until 70, then it just seems like it runs out of steam... Have never gotten it to go any faster than 75/80mph and that is REALLY pushing it! I can hear turbo spin, believe it to be working properly?

(BTW, car did not suddenly start doing this. It was purchased like this)

I had a '81 TD and it would do 85+ all day.

Going to do a valve adjustment this weekend, but is there anything else I should look at?

It NEVER smokes under acceleration, fuel and air filters have been changed. Tank screen not looked at yet.

Any ideas? I don't drive it like this all the time, but sometimes it's not fast enough to keep up with traffic ( won't go faster75-80mph)

WHY???


Thanks guys!

Check the accelerator linkage to make sure it is giving you full fuel.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Sounds like a lack of fuel. Ideas:

Accelerator linkage-check to see that you are getting full travel at the injector pump when you floor it

Tank screen-could be clogged.

Tank vent-could be clogged. If the tank's not too full, try loosening the fuel cap for a test run and see if this helps.

My '83 will do 110 if you stay on it long enough. Yours should definately be going faster than it is.

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

The performance should be much better than that. I agree that it sounds like fuel. Also, valve adjustment and IP timing should be verified.

Thanks guys for the quick replies, keep 'em coming!

99% sure throttle linkage travel is ok, but I'll check this weekend.

Where is the tank vent located? Pictures are always good. I'll try a search on here too, but if you see this and it wouldn't be too much trouble, by all means post location and/or picture.

I'll try these things this weekend, but if anyone else has any other ideas, post away!

-Brian

I'm assuming a search for checking/adjusting/setting IP timing will yield results? If not, could you please post?

Thank you.

There is a ton of discussion here on the best method for adjusting the IP timing, it's fairly complex to do it correctly. Personally, I just let my indy shop do it.

BTW, car did not suddenly start doing this. It was purchased this way.

Thanks.

Do you know when the valves were last adjusted? That's something that is often neglected.

BTW, is this a california car with a trap oxidizer?

I think its not shifting into 4th. I can get my 85 to shift into 4th at 75mph (about 4-4500 rpm). His rpm's shouldn't be that high, especially in an 85 model.


Proof:


http://www.youtube.com/watch?v=r4ZXQv9Toyo

__________________
1981 300SD 512k OM603

Have you cleaned the banjo bolt and line to the ALDA?

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

No, I do not know when the last time the valves were adjusted. I am going to do that this weekend.

This is not a CA car with trap ox.

Thank you for the advice. I'll report back on the valve adjustment after this weekend.

Wow, proof that they really do run 100!

I am almost 99% sure it is shifting into fourth, but again I'll check this weekend. These transmissions start in 2nd, right?

While you have the valve cover off, you might want to check the timing chain "stretch" (which will affect both the cam and IP timing). If you search you will find info on the correct method.

Yes, banjo bolt was cleaned last fall when I got the car. Gunked up with soot at intake manifold.

I have not yet taken the line off and blew/cleaned it out, as well as the Switchover Valve on the firewall.

Will do that this weekend and report back with results.

Thanks for the help everyone, I really appreciate it.