Fuel pump
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
That is true, but fortunately, the pressure is managed by the regulator. Pressure is resistance to flow...neither pump puts out any measurable "pressure" when pumping into a bucket (for example). The stock CFI regulator works just fine w/the higher volume MPFI pump...and even more. I ran a Walbro 255 lph pump in my CFI car, factory regulator set to 15 PSI. 
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Not debating the need for the regulator. OP just has to be aware that there is a major difference. And perhaps be proactive and put in new regulator if he upgrades the pump. The 85 pump will fill your bucket much faster than the 84 pump. 
DAMN sounds like another "bucket list" thread.......
DAMN sounds like another "bucket list" thread.......
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
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Thread Starter
Racer
Joined: Jun 2012
Posts: 325
Likes: 36
From: Colorado Springs Colorado
I already have been looking for the 85 pump assembly, on eBay they show also a what I believe they call a pulsator, now the sending unit assembly does not show a part that looks like what they are selling, where is that part located? The 84 and 85 pump looks the same, is that something that I will need if I use the 85 assembly or is it something not needed? I have not seen that part listed when looking at the 84 units.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
The '84 likely does not have that part due to the low operating pressure, and the design of the '84 pump. The "pulsator" is supposed to operate like an accumulator, smoothing out any pulses crated by the pumping action of the 85^ style pump. It is not necessary in your '84, but it won't hurt to have it either.
Thread Starter
Racer
Joined: Jun 2012
Posts: 325
Likes: 36
From: Colorado Springs Colorado
The '84 likely does not have that part due to the low operating pressure, and the design of the '84 pump. The "pulsator" is supposed to operate like an accumulator, smoothing out any pulses crated by the pumping action of the 85^ style pump. It is not necessary in your '84, but it won't hurt to have it either.
