Primary fuel pressure low voltage
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=51876
Printed Date: April-04-2025 at 10:55am
Topic: Primary fuel pressure low voltage
Posted By: US Brit
Subject: Primary fuel pressure low voltage
Date Posted: February-27-2025 at 6:41am
|
Has anyone come across this on a SN200 with a H6 DTC 91: Primary Fuel Pressure Low Voltage SPN: 94 FMI: 4 Boat will turn over but won't fire, fuel pumps are priming but its like the injectors aren't firing and the fuel is just going round the system TIA |
Replies:
Posted By: KENO
Date Posted: February-27-2025 at 8:59am
|
This would normally be the point where somebody would say "welcome to CCF, but you should ask this on Planetnautique".......but you already did that and got one less response than this one that you're getting here. At least somebody here is replying. I really know very little about that engine in a boat, but those codes are also associated with the land based version of that engine too and I know a little about them (not much though) SPN94 FMI 4 is saying that your fuel compensation pressure sensor circuit has failed low due to maybe a sensor or wiring issue. That goes right along with the DTC 91 code (P0091 on the land based engine. All that would lead me to my local PCM dealer or maybe you can pick the brain of a friendly tech at a Chevy or GMC dealership or some independent shop that deals with these engines, unless you can get your hands on a manual and the appropriate diagnostic scan tools So anyways.......welcome to CCF and good luck
 |
Posted By: Fl Inboards
Date Posted: February-27-2025 at 10:04am
|
has a diacom scan been performed? that generation of PCM engine will show fuel pressure on a scan. or go to harbor freight and get a fuel pressure test gauge and check pressure at the FCC. just because the pumps cycle does not mean they are pumping fuel..Anti siphon valve checked? fuel filter/water seperator checked? ------------- Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise. 1993 Shamrock "fat" 20. 2008 Nautique 196 5.0 |
Posted By: US Brit
Date Posted: February-27-2025 at 11:18am
|
Can I screw the test gauge straight in the top of the FCC? Where is the anti siphon valve? thanks for your help |
Posted By: Fl Inboards
Date Posted: February-27-2025 at 3:24pm
|
The anti siphon valve is located on top of the fuel tank where the fuel feed line leaves the tank. it has a ball and a spring in it that can get clogged and or rusted closed. you will have two fittings one is feed the other is return. the feed fitting looks different and is longer than the return fitting, I would get a scan. if you are going to self diagnose these engine a tech mate from rinda is needed. or search out someone that has a full blown diacom set up and have the engine scanned. on the h6 there is a fuel pressure sending unit on the fcc. for manual testing this unit will need to be removed and shrader valve installed. again cant stress more that you are pushing a chain until you get a real scan.. ------------- Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise. 1993 Shamrock "fat" 20. 2008 Nautique 196 5.0 |
Posted By: KENO
Date Posted: February-27-2025 at 5:23pm
Well, there's the advice from an independent repair shop. Not knowing where you are in Florida, Fl Inboards is in Panama City. I suppose you could be real close or really far away
 |
Fl Inboards wrote: