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  #1  
Old 08-04-2006, 01:58 PM
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Help with PSI readings to ALDA

OK... instead of hijacking another thread I figured I start one. This is for an 87 SDL which I find unusually sluggish... I have not had much drive time with this car, just now getting it on the road and it sat for a few years.

I also probably need a valve job, never done one but picked up some feelers and a metric allen wrench set and I'll attempt it this weekend.

Now for the ALDA readings...

I took two sets of readings. First was from the port on the intake manifold that goes to a valve (see pic for what I mean) which then continues to the ALDA

PEDAL FLOORED: Shift from 1st to 2nd @ 8 PSI @ 3000 RPM, Shift from 2nd to 3rd @ 5-6 PSI @ 3,000 RPM... 3rd? I forget 3rd... darn, didn't write it down.

2nd set is AFTER the valve in the pic.

I floored the pedal...

1st gear shifts kinda hard at 3000RPM with boost 5-6 PSI, 2nd, kinda hard again but almost immediate shift at about 7PSI, RPM didn't have much time to drop from the 3000 mark, maybe 2,700. Soon I was about to bury the gauge at 10PSI so I let up on the pedal and got my shift to 3rd.

Basically I'm thinking these pressures look good. Now I'm wondering if I can tinker with the ALDA, never done it, but if I'm going to have the intake off to do the valve job, maybe I should turn it one way or another? How much? Which way?

Also that hard shifting... I know there's an adjustment down on the tranny by the where a vac line comes in... Should I play with that? weird little fitting where a T comes out and I presume I use that to turn the nut? Or do I just place that T at a different spot or something? Never seen anything like it.

TIA,
Bill

Not flooring the pedal has a tendancy to give me a shift at a lower RPM and lower PSI.
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Help with PSI readings to ALDA-vacuum-valve.jpg  
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'87 300SDL, intensely modified Greasecar setup, with nickle plated heat exchanger, 3 valve setup, 312,000 miles
'95 Suburban diesel, Greasecar basics, 16 plate heat exchanger, mercedes fuel lines, Racor filter
'85 Renault Alliance converted full electric vehicle
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  #2  
Old 08-04-2006, 02:02 PM
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valve adjustment in an SDL...????? you mean valve stem replacement?
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  #3  
Old 08-04-2006, 02:06 PM
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Quote:
Originally Posted by TheDon
valve adjustment in an SDL...????? you mean valve stem replacement?
No idea on the alda (somebody will post who knows) but I do know that the 603 doesnt require valve adjustments.

--Matt
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  #4  
Old 08-04-2006, 02:45 PM
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No valve adjustment required on the 603.......you can toss out those feeler gauges.

Your problem is not the boost. It's the shift points.. This engine should upshift at above 4500 rpm. You can't get the full boost or anywhere near full performance at 3000 rpm. Some of these fellows run the engine to the north side of 5000 rpm for maximum power.

So, instead of screwing with the valves this weekend, you need to make an adjustment to the Bowden cable. This is the cable that provides throttle pressure to the transmission and delays the upshift. The cable needs to be tightened slightly. There is a plastic adjustment ferrule at the mounting point for the cable underneath the hood on the passenger side. The ferrule gets pushed out of the bracket..........rotated for adjustment........and reinserted in the bracket. You are looking to shorten the cable. I'd probably turn the adjusting nut at least 3-4 turns to get the shift points up near 4700 rpm.

Then, take it out for a drive with the boost gauge connected and repeat the test for boost at maximum power above 4000 rpm. You should be above 10 psi..........12 psi would be even better.
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  #5  
Old 08-04-2006, 03:57 PM
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Hey Brian,

Could you post a picture (or a link to a picture) of the location of that Bowden cable adjustment ferrule? Thanks.
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  #6  
Old 08-04-2006, 05:54 PM
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Quote:
Originally Posted by aersloat
Hey Brian,

Could you post a picture (or a link to a picture) of the location of that Bowden cable adjustment ferrule? Thanks.
I don't have a picture, but all you need to do is to go to the bottom of the oil filter housing. You'll see the cable mounting bracket with a black ferrule and a white adjusting nut. The cable is connected to the cruise control linkage.

Impossible to miss it.
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Old 08-04-2006, 10:59 PM
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Oh, bracket below the oil filter housing... yeah... I think I remember relocating that with my veggie oil conversion... :-)

I'll check it out this Saturday.

Thanks,
Bill
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'87 300SDL, intensely modified Greasecar setup, with nickle plated heat exchanger, 3 valve setup, 312,000 miles
'95 Suburban diesel, Greasecar basics, 16 plate heat exchanger, mercedes fuel lines, Racor filter
'85 Renault Alliance converted full electric vehicle
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  #8  
Old 08-04-2006, 11:01 PM
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Quote:
Originally Posted by Bill()C
Oh, bracket below the oil filter housing... yeah... I think I remember relocating that with my veggie oil conversion... :-)

Bill
that could be a problem... or not
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  #9  
Old 08-04-2006, 11:07 PM
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Quote:
Originally Posted by Bill()C
Oh, bracket below the oil filter housing... yeah... I think I remember relocating that with my veggie oil conversion... :-)

I'll check it out this Saturday.

Thanks,
Bill
Actually, the bracket is just forward of, and even with, the bottom of the housing. It's not below the housing.

If you relocated it.........that's definitely your problem because you've lost capability of moving the cable properly when the rack is opened.
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Old 08-04-2006, 11:11 PM
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No it should all be good... It's just an inside joke for me because I've moved all sorts of vacuum parts, etc from their original position.

I'll report back Saturday...

Thanks,
Bill
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'87 300SDL, intensely modified Greasecar setup, with nickle plated heat exchanger, 3 valve setup, 312,000 miles
'95 Suburban diesel, Greasecar basics, 16 plate heat exchanger, mercedes fuel lines, Racor filter
'85 Renault Alliance converted full electric vehicle
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  #11  
Old 08-04-2006, 11:30 PM
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Quote:
Originally Posted by Bill()C
No it should all be good... It's just an inside joke for me because I've moved all sorts of vacuum parts, etc from their original position.

I'll report back Saturday...

Thanks,
Bill
reason veggie conversions are a pita to deal with... they require you to move stuff that should stay where its at
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