One thing I learned about speed-density systems (TBI or TPI), is that you cannot adjust the TPS. Try a fuel cleaner and the work on the regulator. GM used 3 different fuel pressures for the 350 TPI from 40 in 85, 43 in 86, and 87, and in midyear 88 they went to 47. Re: Mercruiser 7. 3) Dead head the pump and see what kind of pressure it can produce. Free Shipping. Typical situation with fuel injection with an intank pump. GREENSIERRA said: FPR is on the intake, disconnect the vacuum hose and see if fuel comes out of it, if it does then you need a new FPR. 2449 posts · Joined 2003. Read full answer. Dec 1, 2012. Re: Only 7psi fuel pressure; 89 350 TBI, pump? 08-12-05 04:45 PM - Post# 759285. Would. Yields 16 to 26 PSI with a stock regulator converted to adjustable. Black Smoke Generation Chevy 350 tbi fuel pressure regulator symptoms can include engine hesitation, stalling, and poor acceleration due to fuel starvation. no gas is getting to the carb. 5 psi may show a good spray pattern, but, it won't start and run a v8. Remove a spark plug and examine the end of it. turning up the fuel pressure seemed like a good idea at teh time, but now that I realize what I did, I think it was a horrible mistake. Engine backfires. Intake leak, injector and fpr leak can cause P0300 multiple misfire though. Like you said factory spec is 9 - 13 PSI, preferably 11 - 13. If I accelerate really slowly then I can get it up to speed. It fires right back up very easily. Safety first -be careful, use common sense and think and act safety all of the time. New Fuel pressure regulator 5. Chevrolet - GMC - Trucks & Vans 8 Cylinder 2 Injector Rochester TBIs. i. 5psi, highest was 13. Replacing fuel pressure regulator typically costs between $100 and $500 including labor, depending on the vehicle’s make and model. Identifying and addressing the specific cause can improve engine performance. Injector firing can be easily verified. if there is. Maybe inspect the TPS as well. 6. When replacing with new plugs, wires, cap, and rotor on a 1991 Chevy, you will. Typically when you first turn on the ignition, the pump will run for about 1/2 second and stop. #1 · Sep 14, 2017. Turns out it was the manifold air temp sensor reading 100 degree air on a 30 degree morning /forums/images. 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. when it is cold, a bit better since the engine needs more fuel. . I am having low end power issues, along with backfiring until you get up to 3000 rpm. If so you can confirm the computer is seeing rotation. Activate the fuel pump (without starting the engine) and observe the pressure reading. (with a return) Factory TBI pumps send 10-12 PSI. 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. Air and Fuel System; Air Conditioning and Heating; Audio; Body Components; Body Panels; Brake Systems and Components;. Everything ran great for about 200 miles, it was definitely WAY more fun to drive then when it was stock. Connect the fuel pressure gauge to the fuel system as you did in the previous section. Walker Products 255-1025 Fuel Pressure Regulator. SKU # 837548. This cost includes labor and the buying cost of fuel pressure regulator material. If ya got a fuel guage hooked up and it has a bleed, crack it so it bleeds off fuel with the engine running. Than it smooths out as truck warms up and runs like a. Perform a Vacuum Test: Start the engine and let it idle. #3 · Feb 20, 2002. I got a 94 full-size blazer with a 350 motor with tbi. In May of 1999 CK5 started out as a tribute to America's favorite 4x4 utility truck. Injector pressures range from 13 to 16 psi (low pressure system) or 35 to 60 psi (high pressure system), and are kept. You can buy one online that. Ok first things first, i bought this vehicle with this problem for dirt cheap. 0L 5. Its a 4. Indiana. 68 volts when I jumpered the fuel pump relay. 3L, 5. Put the 1996 Vortec EP381 pump back in. 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. Watching this video will help you diagnose to see if it is time to replace your fu. Ok first things first, i bought this vehicle with this problem for dirt cheap. During the late 80s and early 90s, TBI systems were used in a variety of different production vehicles. The fuel pressure regulator controls the fuel pressure and should be checked to make sure it is within the manufacturer’s specifications. Check the fuel pressure. . 3L 5. Fits: 1986-95 2. Temporary fuel supply - 350 TBI. In this video, you will learn 7 symptoms of a bad fuel pressure regulator. Posted on Apr 16, 2017. This is the recommended pressure range for the tbi fuel system to function correctly. Surging at idle. Connect negative battery terminal and START engine and observe fuel pressure reading. 11-23-08 05:29 PM - Post#. 68 volts when I jumpered the fuel pump relay. 8 MPG. I had an issue exactly like this with my TPI K5 a couple of years ago that threw no codes but had your symptoms. If you crank it up too much, about 20 it will overwhelm the injector and flow fuel all the time. I have a dead miss on one cylinder at idle - confirmed by cylinder drop test, vacuum gauge shows fast fluctuation 19-21 inHg, and the spark plug is significantly blacker than the others. Asked by phlips904 Apr 02, 2011 at 12:15 AM about the 1989 Chevrolet S-10. -Truck ran great 3 days ago. Jump to Latest Follow. I recommend upgrading to the 1996 Vortec 155lph fuel pump which can support up to 450hp and plugs right into a factory TBI sending unit. The chevy 350 tbi engine is one of the most iconic engines in the gm family of engines. Order Chevrolet K1500 Fuel Pressure Regulator online today. You will most definitely need a pressure regulator, or have to convert to mechanical pump. How much fuel pressure does a 5. You should look up the part number of your fuel pump and make sure how much pressure you're getting. Adapter fitting for GM TBI systems without a fuel access valve test port. 4. motor is new . . some can leak back into the intake. 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. Will it fit a 1991 chevy suburban v2500. Start the engine and let it reach operating. Link to actual testerRECOMMENDED 350 TBI MODS. Different issue from fuel pressure drop. Carbs are about 7-9psi, and IIRC the electric pumps on those will push up to about 20psi. I did a TBI conversion on my 77 350, and from what I remember the return line was smaller diameter. What else could I do? Answer: Check the fuel system pressure. 1. You should see a nice even fan spray of fuel from both injectors as a prime. Bad Acceleration An early sign of a bad GM TBI fuel pressure regulator is bad acceleration. -When I turn the key to run, the pump primes, and I get about 12 PSI of fuel pressure. If the pressure is within the specified range, you can rule out the fuel pump. 3L, 5. hesitation and poor acceleration. Truck Year. with a motor out of a 1986 chevy s10 2. Simple test made difficult by the fuel line arrangement and lack of decent aftermarket. Order yours online today and pick up from the store. I have changed fuel pump,fuel filter,fuel relay,starter relay, and fuel pressure regulator. Check out free battery charging and engine diagnostic testing while you are in store. 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 pressure regulator may be bad, or an injector could be leaking. #1 · Oct 19, 2012. Re: 87 chevy fuel problems. Earl's Performance LT Gen-V Oil Pressure Sensor Kits LT0004ERL. I have to turn it over several times in order to get it to start than I have to feather the gas alot in order to keep it running after a few minutes it idles on its own really low idle. Normal fuel pressure with the motor off and the key on should be 9-13 psi. vacuum line it goes up to 45 psi. MUCH better pump than the EP386 TBI pump. Problems with vapor lock are most common on older vehicles that have a carburetor and a mechanical, engine-driven fuel pump. Proper fuel line pressure should be between 9-13 PSI. The fuel pressure specs for a chevy 350 tbi engine is 9 to 13 psi. has around 230k on the body tranny and. . then once you turn the engine over and build 3 psi of oil the oil pressure switch will then trip the fuel pump relay and turn the fuel pump on as long as 3 psi of is sustained. You may also notice fuel in the vacuum hose. . Important Tips And Suggestions. As a result, you will get poor mileage. Feb 21, 2013. +. 0L, or 5. Fuel Pressure tester link Todays video is dealing with fuel pressure regulator symptoms and testing. my fuel pressure is at 18 psi, specs are to be 9-13 psi straight from the manual. 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. 9. Click image to zoom. 13 psi. Put new distr cap rotor, map - Answered by a verified Chevy Mechanic. 3 5. Such fuel mileage leads to poor acceleration. CFM-Tech Adjustable Fuel PSI Regulator for GM TBI 2. While idling it's not like a heavy misfire just randomly misfiring more like a light stumble and under load it feels under powered and sometime it. so my fuel pressure is right where it. 63. 1995 gm tbi fuel pressure test with OTC's 4480 fuel pressure kit. Testing fuel pressure on a throttle body injection system is similar to testing fuel pressure on an EFI multiport system. I have been working with a spring company to find an assortment of springs to replace the factory spring in the regulator. Share this product . 88 chevy 350tbi. . Fuel should be coming out between the housing and the top plate. 4. for your 305 tbi is 9-13 psi. Carbureted & TBI Engine Year Pressure @ idle (PSI) Others, 2V 1985—86 4. Truck Model. it will start then stays on for a min then shuts off like ran out. Those TBI injectors are known for being noisy but by your description it sounds excessive even for them. Hi I have a 1991 chevy Silverado that just started about a week or 2 ago misfiring randomly and cutting out under load. #3. I have a 1994 S10 Blazer, 4. 1. Gave it a tune up, and it ran beautifully, which was my go ahead to begin going. i hooked my gauge up right at the TB and i was getting 18psi, on the return i was getting (right from the fitting at the TB) 20 psi, and the pump will produce. Testing the. Steps already taken: Replaced fuel filter, threw. Chevy Mechanic:. If you have 15 psi of fuel it shodl only be 9-13 at most so it lmay be the regulator or a blocked return lineIs the fuel pump you installed a high pressure pump? If not and it's just a stock replacement pump they will only achieve about 15-16psi and nothing more. EGR or passages could be blocked by carbon buildup. TBI 14psi fuel regulator replacement spring Fits: 1986-95 2. An expert whose answer got voted for 500 times. Only. Under Pressure. MUCH better pump than the EP386 TBI pump. 6. Solutions for TBI Idle Surge and Stumble. 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. Burb is 91 w/ TBI 350 and 4L80E. By providing a ground path, the ECM energizes the solenoid which then allows vacuum to pass to the EGR valve. Forums. 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. Checking for a vacuum leak is done by listening for hissing noises, which is the easiest method, using a smoke machine which is the most accurate method or. once it warms up runs fine. Runs rough in midrange, actually slows down during part throttle accelleration. Used distributor stem with used cap and rotor and pick up coil or whatever the name is of the third part on the distributor modify your Oem fuel pressure regulator on gm and Chevy TBI units. This would most likely be a failed pressure regulator (also pretty common). I would think 7-8 psi is good. 90 Chevy K2500 350 motor TBI. The 350 was completely rebuilt when the truck was restored. 1991 VIN Z 4. The regulator will throttle it down to 6 psi, but you will burn up the. 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. 10 gears 200K miles. Filter screens get gummed up. Here are different ways to check the operation of a fuel pump and a fuel pressure regulator. TBI) and swap the intake to a Carb one. One method involves using just starting fluid and the other involves using a fuel pressure gauge. This will cause the spring to exert more pressure on the regulator diaphragm and regulate at a higher pressure. Anyway, I'd like to rebuild and/or replace the fuel pressure regulator diaphragm, and possibly the spring, on a 220 TBI unit. Hello and greetings from Germany.