I have a 1989 chevy suburban with a tbi 350. Truck will not start unles i spray starter fluid. After it starts it runs great. Replaced distributer cap, ignition control modual, new plugs and wires, new engine colant temp sensor, new fuel filter new fuel pressure regulator i rebuilt the tbi. When running. The injectors spray in a steady fan. Checked for codes and got a code for a bad knock sensor wich i will be replacing on friday. I had my wife try to start the truck while i watched the injectors. They both pulse. I can hear the pump turn on with key in accessory position. I replaced the fuel pump relay just to be safe. I checked timing with the advance wire unplugged. Timing is at 0. Im getting tired of throwing parts at this truck.what am i missing?
My car has 120000 miles.
My car has an automatic transmission.
Hello and thank you for your question.
Perform a fuel pressure test. Even though the fuel is pulsing out of the injectors with the engine cranking the fuel pressure could be too low. The system must have a minimum of 12 pounds of fuel pressure to start and run. If there is proper fuel pressure and you have spark to the spark plugs, then check to see if there is any vacuum leaks. If there is 15 hg or more with the engine running, then that is okay, but 19 hg to 21 hg is preferred. When checking vacuum with cranking the engine, hold open the throttle plate with a large screwdriver and check for vacuum. If the vacuum is less than 2 hg, then there is a problem with the vacuum system. If the vacuum is normal and all the readings are checking out to be good, then when you can get the engine running, put an engine cleaner or sea foam into the vacuum system and run the engine at 3,000 rpm. Slowly allow the cleaner to drip into the vacuum system. This will clean out the cylinders and valve train that will cause carbon build up. Carbon build up will prevent the cylinder from getting to the proper temperature by sticking the valve open or keeping the rings from sealing properly. Either or starting fluid will ignite at a higher flash rate than gasoline. If you need assistance in diagnosing your no start situation, then seek out a professional, preferably a professional from Your Mechanic to help you with your starter issue.
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