Alternative CIS injectors
05-29-2010, 04:20 PM
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Alternative CIS injectors
Hi
I see that a number of people have used the Mercedes injector 0 437 502 047 rather than the more expensive correct Porsche one 0 437 502 012.
I have come across a number of references that say 0 437 502 010 is the same as 0 437 502 047.
Does anyone have any technical data on these CIS injectors, I have searched and drawn a blank.
John
I see that a number of people have used the Mercedes injector 0 437 502 047 rather than the more expensive correct Porsche one 0 437 502 012.
I have come across a number of references that say 0 437 502 010 is the same as 0 437 502 047.
Does anyone have any technical data on these CIS injectors, I have searched and drawn a blank.
John
05-29-2010, 04:46 PM
#2
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Hi John,
I have researched this subject hoping to confirm that 0437502047 is an acceptable replacement for the 0437502012. The shorter length causes concern with the 928 application. Owners have used them and say they work but some documentary proof would be required before they could be accepted fully as an alternative.
0437502010 cross references to 0437502047 so they are the same.
I have researched this subject hoping to confirm that 0437502047 is an acceptable replacement for the 0437502012. The shorter length causes concern with the 928 application. Owners have used them and say they work but some documentary proof would be required before they could be accepted fully as an alternative.
0437502010 cross references to 0437502047 so they are the same.
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
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928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
05-30-2010, 09:54 AM
#3
I've always felt the stock injector was too long and causes a restriction on the air flow through the port. Also, the shorter injector will put a larger section of the spray cone in the middle of the port so better air/fuel mix can be achieved.
Dennis
Dennis
05-30-2010, 11:13 AM
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Hi Dennis
Do you some first hand experience of using these alternative injectors?
There must of been some reason for Porsche to use the longer injector??
Do you some first hand experience of using these alternative injectors?
There must of been some reason for Porsche to use the longer injector??
05-30-2010, 11:39 AM
#5
John,
Haven't used them yet. I did check the applications for the MB units and see they were used on 81 through 93 MY's so it is possible the shorter units weren't available in 78 and 79.
Dennis
Haven't used them yet. I did check the applications for the MB units and see they were used on 81 through 93 MY's so it is possible the shorter units weren't available in 78 and 79.
Dennis
05-30-2010, 11:48 AM
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Hi Dennis
Ah, good point, maybe Porsche just used what ever was at hand at the time. I have seen a cross sectional drawing on the original injector in situ and the injector does indeed seem to extend a fair way into the inlet port.
John
Ah, good point, maybe Porsche just used what ever was at hand at the time. I have seen a cross sectional drawing on the original injector in situ and the injector does indeed seem to extend a fair way into the inlet port.
John
05-30-2010, 12:13 PM
#7
John,
Also, the major factor affecting fuel delivery (volume) is the fuel distributor. If the pintle opening pressure was higher or the passage diameter was too small, the first thing that would be affected is the idle. I do agree with Roger and would like to see comparison dynos, but I wouldn't be surprised if the MB injectors showed some gains.
Dennis
Also, the major factor affecting fuel delivery (volume) is the fuel distributor. If the pintle opening pressure was higher or the passage diameter was too small, the first thing that would be affected is the idle. I do agree with Roger and would like to see comparison dynos, but I wouldn't be surprised if the MB injectors showed some gains.
Dennis
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05-30-2010, 07:24 PM
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Some where I have seen somebody post that they put in a set of the MB shorter injectors and they worked OK, but dont remember where/who. The ..012 unit was also used on some Peugeot 505 models, but I doubt that widens the availability.
jp 83 Euro S AT 52k
jp 83 Euro S AT 52k
05-31-2010, 04:07 AM
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Yes there is a discussion on 'Pelican' about the shorter Merc ones, the '012' injectors were also used in a Rolls Royce and a Saab. I've got a set of the '047' coming, as I just can't get my existing set of '012's' working nicely.
The burst pressures are all over the place despite intensive cleaning and back flushing, the spray patterns are good, but I guess the pintle springs have changed tension with age and now the pintles open at various pressures, I have a range of 30lb to almost 60lb, so not the the 10% tolerance I would like to see!
John
The burst pressures are all over the place despite intensive cleaning and back flushing, the spray patterns are good, but I guess the pintle springs have changed tension with age and now the pintles open at various pressures, I have a range of 30lb to almost 60lb, so not the the 10% tolerance I would like to see!
John
08-05-2010, 03:01 AM
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Hi
Long story short I ended up with a set of 0 437 502 010 which are the updated version of 0 437 502 047.
After further adventures with the CIS system the car is now running perfectly, revs cleanly and drives as I would expect it to.
I ended up completing theses jobs:
New HT lead set
New Plugs
Replacement injectors (Merc 0 437 502 010)
Strip and clean and rebuild the fuel distributor
Reset WUR using CIS test set (Hot and Cold control pressures)
New Fuel pump and Filter
Reset idle and mixture (CO)
John
Long story short I ended up with a set of 0 437 502 010 which are the updated version of 0 437 502 047.
After further adventures with the CIS system the car is now running perfectly, revs cleanly and drives as I would expect it to.
I ended up completing theses jobs:
New HT lead set
New Plugs
Replacement injectors (Merc 0 437 502 010)
Strip and clean and rebuild the fuel distributor
Reset WUR using CIS test set (Hot and Cold control pressures)
New Fuel pump and Filter
Reset idle and mixture (CO)
John
08-05-2010, 09:19 AM
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08-06-2010, 05:14 AM
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Hi
I have set the WUR up according to the WSM specs for my car.
I vaguely remember reading somewhere that alot of these CIS injectors perform pretty much the same, in that the original '012' injectors have the same flow and burst pressure as the '010'
The primary difference is the length, although there is a school of thought that the shorter '047 or 010' gives better fuel injection..........who knows?
John
John
I have set the WUR up according to the WSM specs for my car.
I vaguely remember reading somewhere that alot of these CIS injectors perform pretty much the same, in that the original '012' injectors have the same flow and burst pressure as the '010'
The primary difference is the length, although there is a school of thought that the shorter '047 or 010' gives better fuel injection..........who knows?
John
John
08-06-2010, 06:34 AM
#15
Nordschleife Master
Hi
I have set the WUR up according to the WSM specs for my car.
I vaguely remember reading somewhere that alot of these CIS injectors perform pretty much the same, in that the original '012' injectors have the same flow and burst pressure as the '010'
The primary difference is the length, although there is a school of thought that the shorter '047 or 010' gives better fuel injection..........who knows?
John
John
I have set the WUR up according to the WSM specs for my car.
I vaguely remember reading somewhere that alot of these CIS injectors perform pretty much the same, in that the original '012' injectors have the same flow and burst pressure as the '010'
The primary difference is the length, although there is a school of thought that the shorter '047 or 010' gives better fuel injection..........who knows?
John
John
The really satisfactory test would be back-to-back dyno's with just the injectors being swapped, but that would require a "properly" functioning original set of injectors to compare, which is rare
