if you were closer I would lend you an extra isspro guage I have sitting around that I'm using to test the same thing on my car as far as boost goes.

I also have an 87 that is in the 1 minute 0-60 class so I'm watching this post closely. I'm also going to try the 2 liter bottle as a fuel tank trick tomorrow if I get a chance.

Not trying to hi-jack the post here but I'll share whatever I come up with in the next couple of days.

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87 300D Turbo (still wondering about #14 head)
98 Buick Regal GS (one quick grocery gettr)
07 Honda CBR1000RR
04 Dodge Ram Laramie 4x4 CTD (heaven)
95 Dodge Ram 3500 CTD. Need snow plowed?

Thanks. I have pretty much ruled out a fuel delivery problem as it will accelerate pretty well when shifted manually, just need to figure out why its in fourth at 20.

If the bowden were broken it wouldn't retract when pulled would it? I looked at the bowden on my "good" car and it has slack in it too. I'm getting so confused, maybe I'm not even looking at the bowden .

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Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

He meant the switchover valve for the overboost protection. You can bypass this and route the intake manifold fitting straight to the ALDA for test purposes. It was mentioned in an earlier post, I think this was already tested.

The 1990-up models have transducers related to the wastegate and other boost-related items, but those don't apply to the 1987 setup.

GSXR-
Swapped OVP's with the other car and no impact on the tach.

Removed the alda and it gave it some speed up to about 15 then flat again.

Will easily rev. to 5K and stay there.

Checked the EGR and heard the thunk, as you expected.

Can't check boost, I thought my Mityvac would do it but its vac. only.

I noticed that it would upshift very fast. Its in top gear by 23mph even with it floored.

Took a look at the tranny. I had checked the fluid and put in a half quart a few days previous but I checked it again and it didn't even show on the dipstick! Anyway, TWO QUARTS later its between the lines. Went for a drive, engaged reverse quicker seemed to pull a little better from a dead stop but still upshifted way to fast. Then I got the bright idea of shifting it manually. Boy what a difference! I got my time down to 16 sec. 0-60. Its almost driveable if shifted manually. If placed in drive and floored it still upshifts way to fast and there is no kick down, even with a known good switch. If floored at 30mph it just slowly accelerates, no downshift. What would make it shift so fast? Bowden cable? Vac. leak? When I removed the alda I didn't plug the vac line, could this be it ?

Since the time has come down significantly it appears I do have some boost, correct?

__________________

Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

id vote for the bowden cable. too much slack on cable means early upshift and almost no downshift. too much tension means late or high rpm upshift an and sensitive downshift.

__________________
'85 300D Turbo - CA Version

which one is it and how do i adjust it?

__________________

Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

Cool - we're some making progress here.

1) Sure sounds to me like the tach sensor is bad, but a voltage check at the 2-prong connector near the OVP relay would confirm this. Also clean the contacts at that plug first, see if that helps.

2) The fact that you saw a power increase with the ALDA tweak is good news. At least it's pulling away from a stop properly now.

3) Revving to 5k easily means an exhaust blockage is unlikely. That's good.

4) Tranny upshifts are controlled entirely by the Bowden cable. I suspect the Bowden cable is disconnected, broken internally, or grossly misadjusted. It's the cable that attaches to the throttle linkage and goes down to the tranny. It will be near the cruise actuator, behind the injection pump, in front of the oil filter. Vacuum controls the shift firmness, not the shift point, so if it's not slipping, flaring, or banging forget about vacuum for now.

5) What you describe sounds a lot like no boost signal to the ALDA. My old white '87 would get to 60mph in about 14 seconds with the ALDA boost pressure signal disconnected, and this would drop to about 11 seconds with the ALDA boost pressure signal present. It's pretty likely you are getting boost but it sure would be nice to confirm that.

6) Have you cleaned out the fitting on the intake manifold, and tried running a hose straight from there to the ALDA, bypassing everything else? If there's no chage with that configuration, you really need to do a boost pressure check. Might be a good excuse to upgrade to the MityVac 4050 (click here for a good price on that.)

7) With that much tranny fluid missing, I'd check for leaks. On my 300E, the O-ring where the dipstick tube goes into the tranny was bad, causing a puddle everywhere it was parked. One dollar for a new O-ring and a few hours later it was leak-free. Blast the whole area with carb cleaner if it's not too oily & dirty. If it's really bad down there, use engine cleaner and a pressure washer first. Get it all bone dry then look for where the ATF is leaking from.

There is slack in the bowden cable and it appears the adjustment is most/all the way out. When pulled the cable has tension on it so it appears not to be broken. Could it be stretched?

Right now the alda is off. I'll back it out 1.5 turns and reinstall this afternoon. I will then try with a vac. hose direct from the manifold to the alda. I noticed no black smoke with the alda off. Shift linkage is sloppy also. Sometimes I have to wiggle it to get it to shift into D.

The car had been sitting for 2 years, I guess it could have lost the tranny fluid over that time. I'll do a tranny service this weekend. Whats the easiest way to find the torque converter drain plug for a man with minimal tools? Do I turn the crank (clockwise when facing the front of the car) until I see the plug?

Thanks again for all the help.

__________________

Muleears
'07 E320 Bluetec 133K my DD
'04 Jaguar XJ8 VDP, 34K
'10 Hyundai Accent 60K Grocery Getter
'02 VW Golf soon to be on the road again
'97 E300 Diesel Son's DD
'61 VERY tolerant wife

Hampton Roads, VA USA

Gone but not forgotten:
'67 250S 95K
'86 300SDL
'87 300D Turbo, 364K! R.I.P.
'98 E300 Turbodiesel, 213K
'02 S420, 164K
'01 Prius 138K

there should be a white turn-buckle-like nut or coupling on top of the valve cover theat attatches the cable that you can turn to increase or decrease the cable tension. (hint: it should be around the rubber boot of the cable). more tension, longer upshift at higher rpm, more slack, shorter upshift at lower rpm.

__________________
'85 300D Turbo - CA Version

whats an ALDA?

Vast simplification: It's the device that tells the injection pump to send more fuel as boost pressure increases, and vice-versa. The pumps tend to lean out as they age and if you tweak the ALDA setting it can return power to normal.

how do u do that? b/c i have similar symtoms, 91 300e 3.0.
if i gun it off the start it accelrates very slowly. but if im driving and gun it , it goes. and when it shifts, its shifting very hard. if i stop and turn a corner, and giving it a little gas, u can har the tires squeel when it shifts hard.
aany ideas?
thanks

Your 300E has a totally different setup than the diesels. but if you are getting hard shifts, I'll almost guarantee you have a vacuum leak between the engine (intake manifold) and the transmission. There is a single vacuum line, check that and make sure it's intact, and the rubber fittings on both ends are not falling apart. The fluid & filter need changing every 30kmi, so do that also if necessary. (Make sure to drain the torque converter also - half the fluid is in there.)

The 300e is a gas engine, no ALDA.

__________________

Gone to the dark side

- Jeff

What does ALDA stand for? Is one of the A's "aneroid"?

__________________
85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked