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Mechanicals / Re: K-jet troubles - totally s...
Last post by raueda1 - 06 August 2022, 01:53 PM
Quote from: Randys01 on 01 August 2022, 03:57 AMIt seems you are nearly there in terms of the correct values for everything except hot control pressure. You have to get that down. At 4000+ feet SLC has slightly less than the ave air pressure but at times it seems it is only by a gnat's whisker. Frankly, I feel as tho it is  a red herring.

There's a million cars a year go to 6000 feet in the Victorian snow fields and no one is in crisis. Indeed my own 6.9 travelled from sea level  up to the mountain top every day for 10 years with a standard WUR.
So forget Hi altitude WUR's .
You have to get the control pressure down to 3.6 then let's see.
Thanks much!!  Got some progress to report.  First, the system pressure is now exactly 5.5 bar and stable.  I played around with a few WURs and seemed to find a good one.  Hot control pressure is 3.5 bar.  Cold pressure is a bit low, ~0.9 bar at 30C ambient.  Should be more like 1.8 bar at that temp, but never mind for the moment.  The car starts instantly and idles very smoothly.  It revs freely and is drivable, kind of. 

So far so good.  But problems remain.  It still bogs down under heavy throttle.  Basically, anything beyond about 1/3 throttle doesn't have any effect.  There are a couple further issues:
  • Static pressure - The system holds static pressure OK for a few minutes, but gradually creeps down.  There don't seem to  hot start problems, though I haven't tried a hot restart after sitting 10 minutes.  So, there's a leak someplace.  For the time being I'll assume it isn't the fuel pump non-return valve since it's new.  Regardless, the leak doesn't seem severe enough to cause lack of power.  Or is that a bad assumption?
  • Fuel pump sucking air - there's a variable hissing noise emanating from the fuel delivery cluster.  It sounds as if air is getting sucked in somehow.  Can that mess things up?  Probably it can, but the power loss was present from the start, so seems unlikely.
  • Full load vac enrichment - Manual indicates that malfunction causes stumble on acceleration and/or lack of power.  Disconnecting the vac hose drops control pressure from 3.5 down to 2.5 bar.  The spec is a drop of only about 0.4 bar as I understand it.  But I tested 2 WURs and both did the same thing.  When the vac hose is disconnected at idle the engine speeds up.Maybe a candidate?

Next steps:
Check fuel accumulator for a leak
Check cold start valve for leak
Confirm air leak and eliminate
How to really check vac enrichment?

That's where I'm at.  Any ideas or suggestions would be wonderful.  This is killing me.  Thanks again,
Mechanicals / Re: A6 Compressor oil fill
Last post by s class - 06 August 2022, 01:41 PM
Bit late to help, but I've fitted a fair number of those apco units.  I usually drain the oil, measure with a syringe and put it back in.  It's typical to only get about 150ml out, if you leave it draining overnight you might get about 220ml out, we'll that's the best I've ever managed.  The rest remains trapped in the various internal chambers.  So yes, despite my concerns, I believe that every unit I've bought did in fact have the claimed 300ml in. 

It's worth pointing out that PAG oil for R134a and mineral oil for R12 are immiscible and having a combination of the two results in a jelly like coagulation and shortened compressor lifespan. 

When we do compressor replacement, we usually do a 'full house' with all new lines, New receiver drier and expansion valve, and chemically flush the evaporator and condenser to eliminate any traces of mineral oil when going over to PAG/R134a
Mechanicals / Re: 450 transmission swap Ques...
Last post by UTn_boy - 06 August 2022, 01:33 PM
Those part numbers are only casting numbers for the case itself, and will be of very little use, if any at all. 

The difference between your original transmission and the one out of the 450SLC is all internal.  The outside physical dimensions are the same, and they're both the same transmission.....a 722.004.  Between 1973 and 1980 there were internal improvements made, but they are interchangeable.  If your mechanic says they won't fit, then we have to assume that he doesn't want to do the job, has bad eye sight, or is ignorant (literal meaning, not the offensive demeanor) on the whole subject matter.  Possibly any combination of all of the above.  Either have him take a leap pf faith and see that they're interchangeable, or find another mechanic. 

Bear in mind that whoever does this swap for you will not be able to warranty or guarantee the used transmission.  So if the transmission out of the 450SLC lasts only three days or starts leaking, then that'll be your tough luck, and nothing to do with whoever installed the transmission.  Installing a used transmission without at least re-sealing it while it is out is very risky.   
Mechanicals / Re: A6 Compressor oil fill
Last post by daantjie - 06 August 2022, 01:19 PM
Well, I charged her up and got 12C at the vent so I'm putting this one in the "W" column ;D for now at least hehe...
I did rotate the clutch unit about 20 times once installed and before running the compressor as everybody online says you need to do this to push excess oil out of the discharge port to prevent hydrolock.  Might be bullshit but I was not going to risk it.
Mechanicals / 450 transmission swap Question
Last post by JHead - 06 August 2022, 01:06 PM
I have recently bought a 1973 450SE with a bad auto transmission. After doing some research I bought a 1980 450SLC auto transmission for the swap. After the mechanic took the original transmission out and compared it to the 1980 one, he thinks it won't fit. He has been light on the details but has sent pictures of the P/N of both - they are the same number with one exception:

1973 450SE   transmission P/N R 115 271 43 01
1980 450SLC transmission P/N R 115 271 42 01

I can't find anything on the internet to decode the P/N or what the '3' or '2' represent.
Does anyone know what this number represents or have any advice on making this swap?

Thanks in advance!
Mechanicals / Re: Exploded Ignition Coil
Last post by gurrier - 06 August 2022, 10:04 AM
Top right shows a fairly hefty in line fuse connected with heavy wire-certainly not OE I would say.
Mechanicals / Re: Exploded Ignition Coil
Last post by johnnyw116 - 06 August 2022, 06:56 AM
Quote from: SteveDuNord on 06 August 2022, 05:47 AMForgive my ignorance but what is all that black gunk?
i guess that gunk is maybe a mixture of the oil what is inside the coil and something that is melted ?
Mechanicals / Re: Exploded Ignition Coil
Last post by SteveDuNord - 06 August 2022, 05:47 AM
Forgive my ignorance but what is all that black gunk?
Mechanicals / Re: Exploded Ignition Coil
Last post by johnnyw116 - 06 August 2022, 04:48 AM
Quote from: Randys01 on 05 August 2022, 10:53 PMsomebody probably left the ignition on! ;D

it happend during driving on a roadtrip through Paris according to the facebook post
Test Drive / Re: New member 6.9
Last post by Randys01 - 06 August 2022, 02:01 AM
Welcome!.Yours is the same as on blue..Dec 78 ..and about the same condition altho I've replaced a lot of stuff...similar mileage.
Yours lived in the dry states...mine lived in the snow?

Ah yes....leaking head gasket. Probably started with no8 cylinder. About 35 manhours I'd say...but it has to be done..