Fuel Pressure Regulator, Chevy, GMC, Hummer, Pontiac, Each. When the fuel pump cycles OFF, pressure should drop to about 6 PSI and hold. I'm thinking it's a distributor problem since it's not sending a signal to the comp to keep the injectors firing. Such fuel mileage leads to poor acceleration. Those TBI injectors are known for being noisy but by your description it sounds excessive even for them. A good way to check a bunch of those things is to remove the air filter and look down into the throttle body while turning the key on. 89' V3500 TBI 454, TH400. 7L 350 TBI with dual tanks. The impeller in the fuel pump will wear down with age (especially cheap Chinese junk ones) and more fuel will bypass internally. 6 . 3. if the engine dies. Fuel. Learn. TBI only runs at about 15 psi. read moreI have a 1987 Chevy R10 Silverado w/ a 5. Location. It is called a Chevy/gm TBI fuel pressure adaptor, tell them that it hooks inline to check the fuel pressure and they should know exactly what you mean. I've replaced the map sensor the fuel pressure regulator in the throttle body. Messages. Could be the pressure regulator, fuel pump, or a restriction such as a plugged in-line fuel filter, plugged tank filter sock, severely kinked hose or sticking tank selector valve. Hogg. Helpful 0 ;. Leaking Fuel. Those that have played. I'm running an inline TBI fuel pump made for this motor. This problem just started, it loads up with gas at idle, black smoke on acceleration. Than it smooths out as truck warms up and runs like a. Signs of a Bad Fuel Pressure Regulator (External Vacuum-Operated Type) Over time, a vacuum-operated pressure regulator can fail—and that usually results in one or more noticeable symptoms. Trans-Dapt 2733 Tbi Open Spacer Chevy. Hi it's a 1994 GMC Sierra standard cab c1500 with the Chevy 350 tbi 5. It may be necessary to monitor fuel pressure while driving the car at various road speeds and/or loads to confirm. Dec 1, 2012. . most are set around 12-16 and should never move from where its set. Answered in 36 minutes by:Other than being annoying, you have normal operating pressure. Important Tips And Suggestions. 3l tbi vin Z / new fuel tank, pump, sending unit, fuel filter,. 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. CK5 has since expanded to include the classic C/K series GM Truck and Suburban as well as past and present GM models. Fuel filter is new, 350 engine, throttle body injection will chug and miss under load when engine warms up but runs fine at idle. I would think 7-8 psi is good. Intake manifold and gasket problems. Surging at idle. 7L (UNDER 8500 GVW) . if there is. It will not start unless I pour fuel in the carb. Was the spring broken? If the spring is broken the fuel pressure will be to low. Ok first things first, i bought this vehicle with this problem for dirt cheap. With TBI the fuel pressure only needs to be 10-15 with 12-13lb's normal. Fuel Delivery System. Surging at idle. 1987 chevy truck tbi 350 , injectors shooting irractically, drip fuel , replaced pressure regulator and throttle position sensor . 3) Dead head the pump and see what kind of pressure it can produce. In tbi trucks, I look for 12-14psi and 2 quarts of volume with the engine running. ) Clogged injector or lean injector - perform an injector balance test. 7L throttle body fuel injection (TBI) GM vehicle is due to a lack of fuel, which usually means that the fuel pump has gone bad. The fuel pump will supply fuel to the TBI unit where the pressure is controlled from 9 to 13 psi (62 to 90 kPa) by the fuel pressure regulator. $300 - $350 (1) $350 - $400 (1). This is an 89 350 tbi. Some other names for this system: central port injection (CPI) "spider injector assembly". 0L 5. TwinTurbo December 29, 2008, 7:40pm #9. 1. ACDelco Professional 217-2286 Throttle Body Fuel Injector Assembly. New pressure regulator diaphragm and TBI injector on a GM TBI Rochester 300. Hello, my '87 Cutlass OBD1 with TBI fails the emissions test because of a rich code #45 at idle. Best Value. With its well. V. Introduced in the 1980s, the tbi (throttle body injection) system was an early form of fuel injection. 13 psi. Injector pressures range from 13 to 16 psi (low pressure system) or 35 to 60 psi (high pressure system), and are kept. This CFM-Tech Adjustable Fuel Pressure Regulator is a "must have" for stock and modified GM tbi engines. The computer automatically zeros (position) it out and therefore it starts with . 28 posts · Joined 2010. If you find a plug in this condition, check the rest of them. 7-liter V-8 should have fuel pressure between 60 and 66 psi. 1. On my 1995 GMC Suburban I've been having shuddering and stalling issues when I'm going in reverse doing a hard stop or idling in the Drive-Thru. that year the spec for fuel pressure on a tbi is 9-13 psi. Fuel related misfires can be caused from not enough fuel. It drops to 37psi when you have it running, if you unplug the fuel reg. A sooty spark plug could just mean the engine is burning oil at that cylinder. modify your Oem fuel pressure regulator on gm and Chevy TBI units. If ya got a fuel guage hooked up and it has a bleed, crack it so it bleeds off fuel with the engine running. #1. Replaced spring problem solved. 1991. 1995 5. 2. The chevy 350 tbi engine is one of the most iconic engines in the gm family of engines. Mine doesn't so, I asked R. The fuel pressure regulator is set for approximately 12 psi (30 psi on '94 & '95 BBC trucks). Activate the fuel pump (without starting the engine) and observe the pressure reading. Check for low regulated fuel pressure water in. Coolant loss. The pump is designed to provide pressurized fuel at about 125. TBIs are usually a tad lean when stock and only get leaner with more modifications. 7/7. 1993 chevy 350 c. 1) Verify voltage at the fuel pump connection. Perform a Vacuum Test: Start the engine and let it idle. Solutions for TBI Idle Surge and Stumble. 0L 305 TBI that had 180,000 miles on it. Though it was fuel pump now its looking like fuel pressure regulator. 88's grizzly/spool, 39. Ignition control module failure modes on TBI engine. Re: New member here looking for some help with 350 TBI running rich. When it goes bad, the engine may hesitate, stall, and have… Next morning I checked fuel pressure, lowest reading was 11. Circuit Description: The ECM operates a solenoid to control the exhaust gas recirculation (EGR) valve. Injectors are above throttle blades so pressure is constant you can. Fuel pressure issue. What else could I do? Answer: Check the fuel system pressure. May 29, 2009 • 1993 Chevrolet C1500. This equates to a 17% to 20% change in injector flow rate over the service range. . motor is new . It ran ok, but was in need of a tune-up. It made the problem more noticeable. This should work on any GM that has a TBI. The next step is to observe the fuel pressure gauge's needle (after your helper stopped cranking the engine). Checking the fuel pressure with a suitable gauge will provide the answer. Year Warranty. 4. In May of 1999 CK5 started out as a tribute to America's favorite 4x4 utility truck. The mechanic changed out the computer, distributor and checked the ignition and MAP sensors. Thick Layer on Spark Plugs. 91 kg/cm 2 ), replace fuel pressure regulator (TBI 700) or fuel meter cover/pressure regulator (TBI 220). One method involves using just starting fluid and the other involves using a fuel pressure gauge. Chevy 350 tbi fuel pressure regulator symptoms can include engine hesitation, stalling, and poor acceleration due to fuel starvation. 5. #1 · Oct 19, 2012. If you end up replacing your fuel pressure regulator, you might. 7L, Edelbrock MPFI, NV4500, Atlas, D44's, high steer, ARB's, 7" custom semi long-arm 3 or 4-link lift, BFG 33x12. If the vehicle’s fuel pressure regulator fails or has any issues it will disturb the fuel pressure of the vehicle. I'm using the stock internal regulator in the TBI unit. T. Replacing the fuel pressure regulator as soon as you notice a problem prevents you from being stranded by an engine that no longer wants to run. New Fuel pump relay 4. 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 should look up the part number of your fuel pump and make sure how much pressure you're getting. 221. Cut the fuel lines just after the fuel filter and loose the connecting pipes that used to go to the TBI. 1987-95 GM Truck 4. If the TBI holds 15 PSI and your pump is designed to run at 30-40 PSI the pump probably won't last long. Introduced in the 1980s, the tbi (throttle body injection) system was an early form of fuel injection. Basic tips on diagnosis and repair of GM's TBI system. I did have a cfm adjustable fuel pressure regulator that I installed to see if it Made a difference. Verify installation: Reconnect the negative battery terminal and start your Chevy Silverado. The primary goal of Step 1 is to get your fuel source set to the pressure you need it to be. 8 MPG. M. Part Number: EAR-LT0004ERL. 73 posts · Joined 2010. First I start with a new Fuel pump, STOCK 75lph TBI fuel pump will only support about 230hp before the fuel pressure drops like a rock. May also want to check the spark timing. 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. Anyway, I'd like to rebuild and/or replace the fuel pressure regulator diaphragm, and possibly the spring, on a 220 TBI unit. Fuel Pump: On 4. Check your regulator to see if it is adjustable. GP Sorensen Fuel Pressure Regulator 800-457. To diagnose a bad fuel pressure regulator, follow these steps: Locate the Fuel Pressure Regulator: Pop the hood and find the fuel pressure regulator. 6—6. The Chevy 350 TBI is designed without a dedicated port for fuel pressure testing. Rcarter96 Discussion starter. T'd a mechanical gauge in with the digital. 0 1597cc, 2555cc TBI 1985—89 35—38 Pressure @ idle (PSI) Pressure @ idle (PSI) w/. The pump should run as long as the jumper is installed. It will not do this again unless the ignition is switched off for at least 15 seconds. the 220 model tbi is different than all of the others because of this. I adjusted the pressure from 10. As a result, you will get poor mileage. musicBetter Luck by tubebackr | promoted by 3. )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. FEEL AND SENSE. TBI mounts the injector (s) right in the throttle body. The check engine. Testing the. to use noid light you have to disconnect fuel injector electrical connector then plug. 454 TBI problems. The filter screens in the fuel tank can gradually get. There are also other symptoms of a bad fuel pump, including:. . Same engine and TBI. A faulty fuel pressure regulator can lead to a wide range of engine performance problems. 3BELTWESTY 8K SNYYes, too high a fuel pressure WILL cause a too rich condition, and your fuel pump is probably the problem. 3 tbi. The pressure regulator is on the throttle body, you would have to check fuel pressure to tell if it's working. The TBI fuel pressure specification for small block Chevy’s is 9 – 13 PSI with the truck running. TBI fuel pressure regulators don't hold pressure after turning off the key. 65. It is also a 3800 fuel pressure regulator symptom. Ships QTY . $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. I've replaced the fuel pump. A short tip for leaking TBI injectors on late 80's to early 90's Chevy fuel injection systems. The primary focus of this video is how to troubleshoot and repair a Central Port Injection system with an internal fuel leak. It's a good thing to have anyways. fuel pump for an SBC is about $12 as apposed to $50-$100 for an electric one. 1985-91 Corvette 350 TPI. Hi I have a 1991 chevy Silverado that just started about a week or 2 ago misfiring randomly and cutting out under load. Runs rough in midrange, actually slows down during part throttle accelleration. It's a torx bit bolt in the bottom of the regulator housing. Adjustable Fuel Pressure Regulator. 1. fuel pump and tank assembly, fuel pump relay, rebuilt fuel pressure regulator. 02 when vehicle is running lean drops to . Its a 4.