Holiday rambler aluma lite 454 tbi too rich won't start
Hello, I have been attempting to revive a 1993 Holiday Rambler aluma-lite for a friend. It is on (I think) a P30 chassis. It has a chevy 454 with tbi. It has about 35,000 miles so obviously it has mostly just sat. I'm not sure how long it's been since it ran but it has been several years, at least. I disconnected the fuel lines to the tank at the tbi, made barb fittings and ran a pump from a gas can on a toggle switch. Getting about 10 psi Through the injectors. The injector wires had melted and shorted to each other from someone pouring gas into the tbi to see if the engine was viable. I repaired the wires and replaced the injector fuse and they seemed to make a good spray pattern. The engine at first fired and sputtered to a halt after about 1.5 seconds. I turned off the pump and tried to start it and it ran a bit longer and then, of course, died. doing things that should ,to my perception, cause it to run leaner allowed it to run.
1) I reduced fuel pressure. This allowed it to start and run poorly.
2) I disconnected the line from the manifold absolute pressure (MAP) sensor and applied vacuum. this allowed it to start and run several and almost reach operating temperature, although throttle response was bad and black smoke would come out with throttle positions above idle. Idle seemed ok with 18 to 22 inches of mercury vacuum pulled on the MAP. Idle was faster with port to the manifold left open. above 22 inches vacuum, the engine would die.
3) I unplugged the 2 wire coolant temp sensor and plugged in a spare. Heating the spare allowed the engine to start and run until the sensor cooled back down in the air.
I have replaced the MAP Sensor, Temp sensor, injectors (suspecting they may not be closing fast enough) and put a new diaphragm in the fuel pressure regulator. The new injectors and fuel pump are AC Delco. I pulled a couple spark plugs and they look very black, but are still making spark across the electrode rather than through the porcelain. I played with the ignition timing and this had little effect withing a reasonable range. Interestingly it did not start well on starting fluid, (fuel pump turned off) but will start and run on gasoline with vacuum pulled on the MAP sensor. I hope to get some voltage values on the Throttle position sensor (TPS) and MAP sensor soon as well as some other sensor values. Have not replaced the oxygen sensor yet but didn't think that would make it run rich the engine was cold. I hope this isn't too long. I will appreciate any replies.
Thank You.
-Ross
1) I reduced fuel pressure. This allowed it to start and run poorly.
2) I disconnected the line from the manifold absolute pressure (MAP) sensor and applied vacuum. this allowed it to start and run several and almost reach operating temperature, although throttle response was bad and black smoke would come out with throttle positions above idle. Idle seemed ok with 18 to 22 inches of mercury vacuum pulled on the MAP. Idle was faster with port to the manifold left open. above 22 inches vacuum, the engine would die.
3) I unplugged the 2 wire coolant temp sensor and plugged in a spare. Heating the spare allowed the engine to start and run until the sensor cooled back down in the air.
I have replaced the MAP Sensor, Temp sensor, injectors (suspecting they may not be closing fast enough) and put a new diaphragm in the fuel pressure regulator. The new injectors and fuel pump are AC Delco. I pulled a couple spark plugs and they look very black, but are still making spark across the electrode rather than through the porcelain. I played with the ignition timing and this had little effect withing a reasonable range. Interestingly it did not start well on starting fluid, (fuel pump turned off) but will start and run on gasoline with vacuum pulled on the MAP sensor. I hope to get some voltage values on the Throttle position sensor (TPS) and MAP sensor soon as well as some other sensor values. Have not replaced the oxygen sensor yet but didn't think that would make it run rich the engine was cold. I hope this isn't too long. I will appreciate any replies.
Thank You.
-Ross
