Have a 2000 4.3L Chevy engine with 120k miles that turns over but wont start....no, its not in an Alero but an Astro. Still GM, close enuff? [img]smileys/smiley2.gif[/img]

Rusty, hoping you are tuned in and might shed some light or have other ideas. I pulled a coil wire and get spark from the coil when cranking. I push the fuel rail shrader valve and fuel leaked out but not forcefully. I turned the ignition key to get the fuel pump to come on then pushed the valve and fuel came out but again not as forcefully as I would expect. I dont have a fuel pressure gauge.

Anyway, I next sprayed starter fluid into the throttle body while cranking and nothing. Also hooked an OBDII tool to the test port and no codes at all.

I am stumped at this point. Kinda wondering if it could be the crankshaft position sensor? The fuel pump/filter is still suspect but I would have expected it to at least try to start when I sprayed starter fluid.

The final clue is in how the engine sounds as it is cranking. It cranks strong for several seconds, then sort of stumbles like a cylinder fired but off sequence. Also when I stop cranking, there is what I can only describe as a low level, muffled backfire at which point I get a whiff of gas and starter fluid.




Edited by: landar

 

How much fuel comes out of the shrader valve? If it doesn''''t shoot out with some pressure thats the problem. I would start at changing the fuel filter first and see how much pressure you get.


Also what shape are the plugs and wires in? If the plugs and wires aren''t good that would explain why it it cranks but doesn''t turn over.Edited by: rustyballs_69

 

Also I''m not sure if it has a distributor or not, looked at some pics of the 4.3l and some had them and some didn''t. If it does have one you might want to get a new cap and rotor button for it.

 

IMO, the fuel did not "shoot" out like I would expect yet it did come out.
What puzzles me is why the starter fluid did not get the thing to at least sputter to life for a second or two. Maybe fuel injection does not work that way with starter fluid. I am used to the old carbureted engines.

I do not think it has a distributor, just a coil with 6 wires attached.
I thought maybe the wires were wet due to some foggy winter weather that we were having so I sprayed them with WD40 to dry them. No difference.

This is a friends van so I am just trying to help out. He is going to tow it to a shop and have them work on it. Fine with me because it is cold outside and no garage to work in! I will let you know what they find.

 

Rusty, the shop said that the distributor cap and rotor were bad. This is a 2000 model, I did not think it even had those archaic parts, thought it was modern. I saw what looked like a coil with six ignition wires coming out. Did not look like a typical distributor because the wires were not evenly spaced. Oh well. You were right about getting a new cap and rotor.
Thanks.




Edited by: landar

 

Glad you got it fixed. I don''t know that motor so I wasn''t really sure if it had a disributor or not.