 Fuel pressure help, 1st start after rebuild |
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| TonyA |
 Mar 16 2026, 12:23 PM
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#1
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Nachmal  Group: Members Posts: 661 Joined: 17-November 16 From: Hilltown PA Member No.: 20,596 Region Association: North East States 
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Doing the first start on a stock 1974 2.0 FI
I have confirmed spark and some fuel. When i put a little gas down the intake it runs a little. My spray at #2 was weak. I had the pump wired backwards. I fixed that. I put a gauge in line after the fuel rail going to the side port of the regulator. I confirmed getting fuel from the side rail after #1 the hose at the end of the regulator goes to the return across the engine to the side return line. I am getting 42PSI. Is this the correct location for the fuel pressure gauge? Is the plumbing correct fuel rail end at #1 to side port and top end port to the return? With this configuration I tried to lower pressure and I cannot. (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) |
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| mgphoto |
Mar 16 2026, 01:07 PM
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#2
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"If there is a mistake it will find me" Group: Members Posts: 1,419 Joined: 1-April 09 From: Los Angeles, CA Member No.: 10,225 Region Association: Southern California |
You should be able to reduce the pressure at the fuel pressure regulator which is at the end of the fuel ring. I think it’s 37 lbs.
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| TonyA |
Mar 16 2026, 01:28 PM
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#3
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Nachmal Group: Members Posts: 661 Joined: 17-November 16 From: Hilltown PA Member No.: 20,596 Region Association: North East States
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Thanks but is the plumbing correctly routed?
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| Ron914 |
Mar 16 2026, 06:39 PM
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#4
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Member Group: Members Posts: 489 Joined: 19-April 22 From: Huntington Beach,Ca Member No.: 26,487 Region Association: Southern California
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QUOTE(TonyA @ Mar 16 2026, 01:23 PM)  Doing the first start on a stock 1974 2.0 FI I have confirmed spark and some fuel. When i put a little gas down the intake it runs a little. My spray at #2 was weak. I had the pump wired backwards. I fixed that. I put a gauge in line after the fuel rail going to the side port of the regulator. I confirmed getting fuel from the side rail after #1 the hose at the end of the regulator goes to the return across the engine to the side return line. I am getting 42PSI. Is this the correct location for the fuel pressure gauge? Is the plumbing correct fuel rail end at #1 to side port and top end port to the return? With this configuration I tried to lower pressure and I cannot. (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/confused24.gif) Hello , My supply comes in on the passenger side and feeds # 3 & 4 Cyl then crosses over to driver side fuel rail and feeds #2 & 1 Cyl then to the port on the side of fuel pressure regulator then out the bottom back to the return to tank . Fuel pressure should be around 29.3 psi . My car is a 76 2.oL D-Jet Fi   |
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| TonyA |
Mar 17 2026, 05:34 AM
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#5
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Nachmal Group: Members Posts: 661 Joined: 17-November 16 From: Hilltown PA Member No.: 20,596 Region Association: North East States
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thanks....my plumbing is correct then
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| Dave_Darling |
Mar 17 2026, 07:10 PM
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#6
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914 Idiot Group: Members Posts: 15,331 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California
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The pressure gauge should tee into the high-pressure fuel loop somewhere. You don't want to dead-head the high-pressure part to the gauge, you will wind up with very high pressure that you can't change.
Depending on the plumbing in your car, you can run the hose that goes to the cold-start valve to the gauge. AFAIK, the 2.0 cars should have a single fuel hose that goes to the cold start valve. Just unhook that from the valve and hook it to the gauge. Other years/engine sizes may have two hoses going to the CSV. If that is the case, you can put together a Tee using brass plumbing supplies and swap that Tee in where the CSV is, then run one leg of the Tee to the gauge. Using the CSV spot as the location for the gauge should mean that the gauge is showing the pressure in the high-pressure loop that feeds the injectors, which is the important pressure that we care about. The high-pressure loop is everything "downstream" of the fuel pump and "upstream" of the fuel pressure regulator. --DD |
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| TonyA |
Mar 20 2026, 05:35 AM
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#7
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Nachmal Group: Members Posts: 661 Joined: 17-November 16 From: Hilltown PA Member No.: 20,596 Region Association: North East States
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Thanks. I got it dialed in.
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| emerygt350 |
Mar 20 2026, 06:22 AM
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#8
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Advanced Member Group: Members Posts: 3,487 Joined: 20-July 21 From: Upstate, NY Member No.: 25,740 Region Association: North East States |
Just in case.... the fuel pressure number you are after is 29.
42 will make your car run so rich you will fill your oil pan with gas and wash the cylinder walls of all lubrication. |
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