7 TBI. Sent my injectors BACK out to an independent shop to be flow tested again, just to be sure the first place didn't make a mistake. You may want to turn the key on for 2-3 seconds, then turn to start. 1995 gm tbi fuel pressure test with OTC's 4480 fuel pressure kit. Misfires. 0L 5. A fuel pressure regulator is responsible for providing a consistent fuel supply while driving. When it goes bad, the engine may hesitate, stall, and have… Next morning I checked fuel pressure, lowest reading was 11. JET Performance Adjustable Fuel Pressure Regulator 1987-95 GM Truck 4. Without a pressure regulator, the fuel pump can run. Each TBI has a complete one year warranty. How to check fuel pressure on a general motors truck and what easy checks you can do to diagnose a fuel pressure regulator problemcheck out my other videosht. The fuel pressure regulator controls the fuel pressure and should be checked to make sure it is within the manufacturer’s specifications. 1. A vehicle that won’t start or stalls. The result is more complete, more powerful combustion than with TBI – and better for modified performance engines. It came with a 5. Dec 29, 2023. Throttle Body Injection Fuel Pressure. 869 posts · Joined 2003. Hi all -- new to this forum because I have not had any problems with my Chevy van in tens of thousands of miles. New spark plugs and wires, new distributor cap and rotor, new fuel pressure regulator, new EGR valve, New MAP Sensor, New IAC valve, New fuel filter, and just two days ago the new gasket for the throttle body unit and. . 4WD. 4. skip to main content. 1. Model specific subject matter experts, classified ads and more. If its GM throttle body based, the pressure regulator is built into the TBI. If you need more help to. Jump to Latest Follow. 2) Pump worn out or rotor not turning with the motor. Check the Vacuum Line: Detach. 1991. Re: Mercruiser 7. 1986 Chevy G20 Tow Rig - 5. Carbureted & TBI Engine Year Pressure @ idle (PSI) Others, 2V 1985—86 4. Its pretty important to keep the return fuel line because your carb can only handle 6psi max. Under Pressure. . I tried to be as thorough as possible. New pressure regulator diaphragm and TBI injector on a GM TBI Rochester 300. In this post, we will discuss what it means to have high fuel pressure, what symptoms to look out for and, ultimately, what your best course of action is when you’re experiencing high fuel pressure. . The pressure regulator is on the throttle body, you would have to check fuel pressure to tell if it's working. This is the recommended pressure range for the tbi fuel system to function correctly. 89 4. Free Shipping. Swap the distributor and coil to an HEI unit. The key is to get the right kind of pressure regulator in place to drop the PSI to a level perfect. Fuel pressure under all running conditions is always 12-13psi. 0L or 5. First thought was excessive fuel pressure. 2 volts before considering it WOT, but I have also seen 4. Let's talk about the thing that could be causing this. To diagnose bad fuel injectors in your Chevy Silverado, start by performing a fuel pressure test. The pump should run as long as the jumper is installed. This is the recommended pressure range for the tbi fuel system to function correctly. TBI engines should not “diesel” (run-on) when shut off because there should be no fuel. A Chevy 350 engine needs 8 to 10 psi of fuel pressure for proper operation. TIP 1: You'll need a fuel pressure gauge to troubleshoot the fuel injector assembly on your GM 4. The regulator will throttle it down to 6 psi, but you will burn up the. To test the regulator, with engine at idle, pull the vacuum hose off the regulator. V2500 Silverado Suburban. Find many great new & used options and get the best deals for ACDelco 217-389 17064317 TBI Fuel Pressure Regulator Cover GM 220 Throttle Body at the best online prices at eBay! Free shipping for many products!. . -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. Read that it should be 11psi after the regulator. 7L, Edelbrock MPFI, NV4500, Atlas, D44's, high steer, ARB's, 7" custom semi long-arm 3 or 4-link lift, BFG 33x12. 1. It looks like a dome just behind the injectors on top of the TB. $65 which is really nothing more than the factory unit with a large adjusting screw! Thus I felt it neccessary to show my TBI bretheren the simplicity of performing this modification. T'd a mechanical gauge in with the digital. 3L, 5. I did a TBI conversion on my 77 350, and from what I remember the return line was smaller diameter. These trucks can start and run with a faulty ECM. 3 tbi, it was running rough coughing, backfiring and idling rough. 1. #1. Turbo city actually markets an adjustable fuel pressure regulator for approx. No sound from fuel pump (I assume it's electric and that I should be able to hear it running like I can in my 2002 Chevy pickup). 2466 posts · Joined 2005. Modifying the LT1 fuel system for third gen use. It is like standing on a ladder, and complaining about the height. the 220 model tbi is different than all of the others because of this. Max hp is about 330 hp because of the limitations of the fuel injectors. 85 SS (SOLD), Wicked Ruby Red, Gm Crate 350, Vortec. This answer was rated: ★★★★★. The computer automatically zeros (position) it out and therefore it starts with . Bad Acceleration An early sign of a bad GM TBI fuel pressure regulator is bad acceleration. they are both reading 9 PSI with the fuel pump relay jumpered. Im in search of a regulator spring for the stock tbi regulator that has been made adjustable. It IS flooded. Check Engine Light. 1. Chevrolet C2500 4x2: i have an 1988 chevy c2500 350 tbi (365,000 i have an 1988 chevy c2500 350 tbi (365,000 miles on original engine) was running fine started running rough and stalled at idle, determined the fuel injectors went out, replaced fuel injectors and re. 7 TBI Fuel Pressure Regulator (Topic#203809) Koolhand233 Forum Newbie Posts: 18 Loc: Maryville, TN Reg: 11-23-08. The GM TBI throttle body has the pressure regulator built into it. Temporary fuel supply - 350 TBI. The fact the engine will fire on a prime of fuel but not keep going is proof positive that it isn't getting fuel. I was checking for. I've been trying to figure out a problem with stumbling, hesitating, and dying. You should also be able to use this write-up as a guide for basic TBI overhauls or fuel injector replacing. So I begin every project with a new. Fortunately, the fuel system in a car requires only minor tweaks. Rcarter96 Discussion starter. 4. 7L TBI intermittently stumbles/stalls at idle, and frequently falls flat on acceleration down the - Answered by a verified Chevy Mechanic. This is generally way too high for a carb. you can also have a bad fuel pressure regulator. Dirty fuel filter. Chevy 350 tbi fuel pressure regulator symptoms can include engine hesitation, stalling, and poor acceleration due to fuel starvation. The fuel pressure specs. The. . The fuel pressure regulator in a chevy 350 tbi controls the fuel pressure and regulates the amount of fuel that gets delivered to the engine. #1. Connect your fuel pressure gauge to the Schrader valve (see photo above). Fuel is delivered to the throttle body injection system by an electric fuel pump located in the fuel tank. #2 · Nov 4, 2009. Here is a more detailed list of the signs of a bad or failing MAP sensor you should look for: 1. This page is dedicated to the owners of these vehicles equipped with GM's dual point fuel injection (model 220 tbi). $157. Thick Layer on Spark Plugs. 3 tbi. the pressure should increase a few psi, then return to normal. Also when we were down there we replaced the fuel filter. 04 kB, 700x393 - viewed 820 times. And the air injection system was removed but the engine wiring harness wasn't changed (could be a problem)? Anyways, I've been through 3 different computers, it's currently running best on one from an '87. . Injectors are above throttle blades so pressure is constant you can. Hi allen, I think you will find that your normal pressure should be 60 PSI. my fuel pressure is at 18 psi, specs are to be 9-13 psi straight from the manual. Just a suggestion but you could run a mechanical fuel pump on the ZX depending on how far you have it set back. whats wrong?If yes, bad fpr, injector leaky and fuel pump check valve could be culprit. 16 psi is to the high end but completely managed by the tbi fuel pressure regulator. I would have liked to run the truck for a while with the fuel pressure gauge, but couldn't because the damn gauge kit was so worn and abused it leaked fuel everywhere. SKU # 837548. New Fuel pressure regulator 5. It ensures the fuel pressure doesn’t go higher than the recommended level. I had an issue exactly like this with my TPI K5 a couple of years ago that threw no codes but had your symptoms. New posts Search forums. Walker Products 255-1025 Fuel Pressure Regulator. 88's grizzly/spool, 39. low) could cause rich running, you should see approx. Oct 14, 2009 • 1989 GMC Suburban. In this case you just have a really extended crank (engine needs to build 7psi oil pressure for the pump to run, and then the fuel pump needs to pressurize the lines) but it will eventually run. Shop Fuel Pressure Regulators at Summit Racing. New Fuel pump 2. FEEL AND SENSE. 3L 5. Check fuel pump coupling. cant get it to run right. com the video, 1A Auto shows how to remove and replace a faulty fuel press. When it goes bad, the engine may hesitate, stall, and have…Each TBI comes complete with injectors, TPS, air control valve, and throttle body bushings. 63. #5 · Nov 3, 2010. Most fuel injection systems require a minimum of 43. ManufacturerBuy FUEL INJECTION TUNE-UP REBUILD KIT - TBI 295 1990-1994 GMC Truck C50-70 P41 4. Large, easy to read 0-60 psi scale. To control fuel pressure, the fuel pressure regulator routes excess fuel back to the fuel tank. And yes it is straining to get up speed. 050 (around 235 degrees intake with 245 to 249 degrees exhaust) and excessively tight lobe separation (107 or. Had fuel pump and sending unit replaced, fuel filter, map sensor, coolant temp sensor, EGR, IAC motor, TPS. Once it does it fires no problem and idles very nice in park and neutral. Chevy 350 TBI bogs on acceleration due to the following reasons: Leaky vacuum lines. Connect negative battery terminal and START engine and observe fuel pressure reading. )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. The Spider injector system started in 96. Re: Re: Re: req'd fuel pressure for a tbi 350. 20150720_213922. I. This solenoid is normally closed. 28 posts · Joined 2010. Injectors dumping too much gas. Then just run the fuel pressure regulator to the carb. -30 gal/hr. read moreI have a 1987 Chevy R10 Silverado w/ a 5. 5. Injector pressures range from 13 to 16 psi (low pressure system) or 35 to 60 psi (high pressure system), and are kept. This device is sealed on both sides. One of the first symptoms of a possible issue with the fuel pressure regulator is engine performance issues. One of the first symptoms of a possible issue with the fuel pressure regulator is engine performance issues. The correct Chevy 350 TBI fuel pressure is between 9 to 13 PSI. It sounds like a fuel pressure issue. In response to dragula. 7L and 1987-93 7. I have replaced fuel pump,. The needle should descend to about 40 to 45 PSI and stay there for at least 4 to 5 minutes. 3 L VIN W engine. The fuel pump should be in the 20s. Trainwreck Discussion starter. 994 Chevy Truck K 1500 Truck 4WD V8-350 5. The engine control unit constantly monitors all the sensors in your car engine while you drive the car. Check the vacuum lines. check fuel pressure TBI injection fuel pressure should be 9 - 13 psi. During the late 80s and early 90s, TBI systems were used in a variety of different production vehicles. 3 ltr. In this tutorial, I'm going to show you two different methods to verify if the no-start condition on your 4. With a service range of 9 to 13 psi being considered good. 7 Vortec fuel pressure regulator can save lots of trouble and give you a head start at solving engine issues. Remove a spark plug and examine the end of it. We'll provi. If pressure is less than 9 psi (. Fuel Pressure is critical for proper operation. These engines are notorious for carbon plugging up the vacuum ports in the throttle body causing it to not get the correct vacuum signal to the map sensor. Tighten gauge in line to insure no leaks occur during testing. just my 2 cents. New Fuel filter 3. New engine and Trans and Tourqe converter, New fuel pump and Filter. Read full answer. if you have it you can see two lines for fuel one is bigger than the other. Location.