1989 Chevy Suburban Can not stay on, or will not start

enricobr · Posted at Thu Nov 19, 2009 1:14 pm

Engine Mechanical problem
1989 Chevy Suburban V8 Four Wheel Drive Automatic 150,00 miles

Ok, my 1989 Chevy Sub, 5.7 liter, 4wd will not start. The truck has been sitting for 3 years - with out being started. It had a 1/2 tank of gas sitting in it for those years.
I changed the oil and filter, the PVC valve, the fuel filter, air filter, battery and added 24 ounces of dry gas for the 20 gallons of gas in the tank. I also cleaned the carb with carberator cleaner and added about another 5 gallons of fresh gas. The truck will only start if I pour gas or spray carb cleaner in the carberator, it will stay on for 3 or 4 seconds, and then die. In that time, if i press the gas peda,l it will rev as much as I press. Right before it dies, the check engine light comes on. What should I try?

jdl123 · Posted at Thu Nov 19, 2009 1:24 pm

welcome to the forum, use a gage and check fuel pressure, TBI around 10 psi. Can you see the injectors spray gas, engine cranking. Even if the injectors are spraying, 5 psi, will not start a v8 engine, in my opinion. If you crank it long enough and the injectors are spraying, you might finally get enough gas to start,but, it will run poorly and die quickly. Any codes?

enricobr · Posted at Thu Nov 19, 2009 1:32 pm

Thank you very much for your reponse. Where would I hook up the gage? The engine cranks and for the 4 seconds its on, it sounds great.

jdl123 · Posted at Thu Nov 19, 2009 2:04 pm

It's easiest for me at the fuel filter. Not enough room in the engine compartment for a old man to climb up in there, stay squatted down, tying into the supply line at the throttle-body. Last time i tried that, I have to remove the coil and bracket to get enough room to back out the supply line.

enricobr · Posted at Thu Nov 19, 2009 5:28 pm

Ok, I looked at the carberator and saw no gas coming out of the injectors while tring to start it. Thank you for your help, I really appreciate it.

enricobr · Posted at Fri Nov 20, 2009 6:54 am

I checked the injectors and saw no gas spraying out, I am going to disconnect the fuel filter and see if gas shoots out, to try and rule out the fuel pump. Any suggestions as to what else i could try to clean out the entire fuel system?
thanks

jdl123 · Posted at Fri Nov 20, 2009 7:45 am

Use a noid lite on injector electrical connector, see if there is a pulse, engine cranking. Basically, check for B+ and ground at the injector.

enricobr · Posted at Sat Nov 21, 2009 7:07 am

Thank you for your reply. I have fixed the problem, and I will share with you what I did. I took a very basic approach. First - I looked at the injectors and noticed no spray while cranking. Then, I disconnected the fuel filter and noticed no flow of gas coming out of the fuel line while cranking. Then, I checked all the fuses, they were OK, I also checked for power at the fuel pump, and there was power. So now, I pumped some air into the fuel line, using a bike pump, to rule out a clogged fuel line, and I could hear gas bubble in the tank. I then tried to start it again, with no luck. Finally, I dropped the tank, disassembled the fuel pump assembly, and replaced the pump, O-rings and gasket only. I put it all back together again, and it was a great success! Thank you for all your input!

jdl123 · Posted at Sat Nov 21, 2009 8:10 am

Glad you got it going your way.