Replace it if necessary. 6—6. 3 V6, teh FPR has no hose, its mounted inside the intakemanifold plenum where the entire FPR is exposed to vacuum. Monitor your adjustment with a fuel pressure gauge. Vortec 383, modified TBI/4L80e. Tighten gauge in line to insure no leaks occur during testing. 4L MPI Fuel Pressure Issue. I recently put on an Edelbrock high rise TBI intake, new TBI, 14 PSI fuel pressure regulator spring, new fuel injectors, deleted power steering, deleted A/C, and installed an electronic water pump. Replies 26 Views 1K. GP Sorensen Fuel Pressure Regulator 800-457. TBI only runs at about 15 psi. Hope this helps. This will in turn throw off the engine’s air fuel ratio and tune which can have a dramatic effect on the performance. Invest in an AC Delco pump AND filter (a plugged filter will wear out a pump prematurely too). Watching this video will help you diagnose to see if it is time to replace your fu. Vehicles equipped with a returnless system manage fuel flow without a return line to the fuel tank and with no externally seated regulator. Was the spring broken? If the spring is broken the fuel pressure will be to low. 279 posts · Joined 2000. 95 Z-71 with 350 5. This is the recommended pressure range for the tbi fuel system to function correctly. One of the first symptoms of a possible issue with the fuel pressure regulator is engine performance issues. This should work on any GM that has a TBI. -specs unknown (even Indmar said they did not know and that this is the closest thing they carry to the stock pump that is no longer manufactured). Re: Re: Re: req'd fuel pressure for a tbi 350. 4L BBC motors. -Static psi 120lbs. Adjustable Fuel Pressure Regulator. 1. I did a TBI conversion on my 77 350, and from what I remember the return line was smaller diameter. Jan 16, 2010. $98. If ya got a fuel guage hooked up and it has a bleed, crack it so it bleeds off fuel with the engine running. Typically we either don’t get enough or we get too much. 93 chevy 350 throddle body problem. If not, Turn engine OFF to relieve system pressure. with a motor out of a 1986 chevy s10 2. 1995 Silverado,Z71, 3-inch lift,2-inch leveling kit, SkyJacker Suspension, short. With a service range of 9 to 13 psi being considered good. Invest in an AC Delco pump AND filter (a plugged filter will wear out a pump prematurely too). The fuel pressure regulator is set for approximately 12 psi (30 psi on '94 & '95 BBC trucks). The pump maybe pumping but it might not be putting out enough pressure for your efi system. 213. Verify installation: Reconnect the negative battery terminal and start your Chevy Silverado. 4. 7 Vortec fuel pressure regulator problem, you can start by checking the spark plugs. -After it's done priming it drops to about 8 psi, then bleeds to zero within a couple seconds-Cranking the engine seems to have no impactThe cams ground for our carbureted Cheap 350 engine just have too much duration at 0. It is like standing on a ladder, and complaining about the height. TPI needs more like 50-60psi. Reduced fuel mileage. Fuel Pressure tester kit used. i. 5. Quiet and long lasting, but weak fuel delivery. It has a hard time with ANY load (even the A/C compressor). go to auto parts store buy noid light. MUCH better pump than the EP386 TBI pump. -Max running 43psi. It has been going on from the. Every TBI will be Flow Bench tested, calibrated, and idle adjusted making it ready for easy installation. Oh well At least I got to clean o. ok so im not much of a forum guy so i figured since i have exhausted all my mechanical knowledge on attempting a repair and diagnostic of why my sysmptoms are there. #2. Intake leak, injector and fpr leak can cause P0300 multiple misfire though. . Question type: Maintenance & Repair. Fuel Pressure tester link Todays video is dealing with fuel pressure regulator symptoms and testing. 1990 c1500 350 5. my fuel pressure is at 18 psi, specs are to be 9-13 psi straight from the manual. Connect negative battery terminal and START engine and observe fuel pressure reading. The causes for this imbalance of fuel pressure typically include either a bad fuel regulator or a clogged return line. You can connect the tach. When the fuel pump cycles OFF, pressure should drop to about 6 PSI and hold. When the engine is cranked, and if the IAC does not open at all the engine will usually “load up” or “flood”. 20150720_213922. Carbs are about 7-9psi, and IIRC the electric pumps on those will push up to about 20psi. Was going to mention the coolant temp sensor. The chevy 350 tbi engine is one of the most iconic engines in the gm family of engines. It has a 4. 9. The result is more complete, more powerful combustion than with TBI – and better for modified performance engines. Fuel Pump & Pressure Regulator Fittings; Tee & Y-Fittings & Distribution Blocks; Hose Barb Fittings & Adapters. TBI engines should not “diesel” (run-on) when shut off because there should be no fuel. Here is a more detailed list of the signs of a bad or failing MAP sensor you should look for: 1. If you ever suspect a fuel pump isn't working, I'd recommend pulling the fuel pump relay and jumpering the wires from B (+) to the pump supply. . Hi all -- new to this forum because I have not had any problems with my Chevy van in tens of thousands of miles. 4. This is the recommended pressure range for the tbi fuel system to function correctly. TPI needs more like 50-60psi. I have had a series of issues with the conversion and for the money I’ve put into it trying to get it to run properly, I could have dropped a 350 in. Pinch off the return line or just dead head the supply line and tell us what the pressure is then. I replaced the plugs, wires, cap, rotor, and air filter. 1. 3 L VIN W engine. Try bending the rotor spring up to put a little more pressure on the carbon (hopefully) button inside the cap. Save Article. It may be a weak coil or possibly weak spring pressure of the rotor. Find our best fitting fuel pressure regulators for your vehicle and enjoy free next day delivery or same day pickup at a store near you!I got a 95 1500 chevy 4x4. 3L 5. 1. . To test the regulator, with engine at idle, pull the vacuum hose off the regulator. We'll provi. FEEL AND SENSE. Typically when you first turn on the ignition, the pump will run for about 1/2 second and stop. 63. 3. Dec 1, 2012. Ships QTY . then the distributor. 7L 350TBI erratic idle and stalling at low RPMs. 0-liter or 5. First thought was excessive fuel pressure. Answered in 36 minutes by:Other than being annoying, you have normal operating pressure. . Check for any fuel leaks around the fuel pressure regulator. Vortec 383, modified TBI/4L80e. CJeep77 said: WRONG - tbi is 11 to 14 lbs pressure stock! A stock tbi injector can go up to about 30 psi though:flipoff2: This is absolutely correct. Runs rough in midrange, actually slows down during part throttle accelleration. Put the 1996 Vortec EP381 pump back in. As for the original 2. Bad coolant temp sensor. Its a 4. 8L 4. . Idle will be unstable and rough. This type of setup, which operates at relatively low pressure and locates the fuel. The injectors are spraying way too much fuel. You should check to make sure the regulator is doing its job. 7 Chevy take? Fuel Pressure Specification Trucks with either the 5. if all is good check see if PCM firing the fuel injectors. 7L 350 TBI out of. 1991 Chevy Suburban 1/2 ton 2WD w/ chevy SBC 350-3/4 ton drivetrain upgrade w/4. With tbi fuel injection, the fuel pressure is 9--13 psi. Black smoke from the exhaust. 20% off orders over $125* + Free Ground Shipping** Eligible Ship-To-Home Items Only. Those TBI injectors are known for being noisy but by your description it sounds excessive even for them. Hogg. Verified fuel pressure - 6PSI low pressure pump, 30 PSI high pressure, measured at the TBI. Posted on Apr 16, 2017. The fuel pressure specs for a chevy 350 tbi engine is 9 to 13 psi. Chevy Truck Tech Forums. Forums. motor is new . 4WD. This would be dripping out the vent hole at the bottom or side of the pressure regulator. Injector & TBI Unit InformationEven on a Q-jet-equipped, small-block, 350 Chevy, the exhaust is the most critical point. The Pure Choice braided -6 Teflon line threads onto the adapter. )How to install an adjustable fuel pressure regulator on a GM TBI systemthis gives you the ability to adjust fuel pressure and fix the low pressure the factor. A vehicle that won’t start or stalls. Had fuel pump and sending unit replaced, fuel filter, map sensor, coolant temp sensor, EGR, IAC motor, TPS. This is the girlfriend's '93 C1500 5. 7/auto, used short block with fresh heads installed 25K miles ago - those of you that followed the project may remember I replaced a ton of items as well to ensure its reliability. Put new distr cap rotor, map - Answered by a verified Chevy Mechanic. fuel pump relay with another one that is known good. 2) Verify that the fuel pressure gauge is accurate. I have a 98 Chevy truck 1500 v8 350. 12. Defective temp sensor. relays. Re: 87 chevy fuel problems. Injector firing can be easily verified. Truck Year. 3. 0L 5. It’s a single compact unit that mounts atop the intake manifold in pretty much the same way as a carburetor — hence the appeal to automakers. Ok first things first, i bought this vehicle with this problem for dirt cheap. check fuel pressure TBI injection fuel pressure should be 9 - 13 psi. 7L TBI intermittently stumbles/stalls at idle, and frequently falls flat on acceleration down the - Answered by a verified Chevy Mechanic. . Been a while but I'm almost positive there is a filter/screen inside the tank besides the one on the rail. 4l/454 but at a much higher pressure. 1) Verify voltage at the fuel pump connection. 8 MPG. Got a no start condition on my '94 TBI 350. If this vi. i have a 1990 chev 1500 with 5. start with getting the fuel pressure tested, there is a good chance this a bad filter or fuel pump, and revving it up in nuetral does not exclude this, in most cases of a bad fuel pump, filter or regulator the vehicle revs normaly in neutral. Re: 1987 Chevy Truck Issues (TBI) ok heres how the fuel system works on the tbi, engine gets primed for 3 seconds when ecm is first powered on. Features: Test fuel pump check valve, fuel rail pop-off pressure, fuel rail deterioration, and leaking injectors. 73 posts · Joined 2010. One of the first symptoms of a possible issue with the fuel pressure regulator is engine performance issues. TBIs are usually a tad lean when stock and only get leaner with more modifications. . 63. You'll want to add a adjustable fuel pressure regulator to the fuel line. The pump should run as long as the jumper is installed. It started at a stop light about a month and a half ago. 44899) formulation offers maximum protection against sludge buildup, viscosity breakdown, oxidation, corrosion, and thermal breakdown while delivering excellent fuel economy benefits. ACDelco Professional 217-2286 Throttle Body Fuel Injector Assembly. 7L is OK and not the cause of your no-start condition. Looking at both of these symptoms I would be checking the voltages at the coil, both with key on, and while cranking to make sure the voltage is 12V with key on and. New posts Search forums. 1. 350 TBI. Since then it has grown to be a leader among full size Chevrolet K5 Blazer and GMC Jimmy web sites across the Internet. Modifying the LT1 fuel system for third gen use. cant get it to run right. I will be using an aftermarket fuel pump and regulator and i need to know the req'd fuel pressure to make this thing.