Hi guys I need help with my 86 Fiero v6. It recently was having problems at idle and seemed like it was only running in a couple cylinders at low rpm’s. Today it shut off on me and I can’t get it started it’ll crank and fire in one cylinder all day but it won’t start even with starting fluid. It seems to have spark and the compression averages about 125 psi. The concerning thing is that there seems to be a lot of oil in the cylinders cuz every time I take the compression tool off it’s completely full of oil but the car only ever smoked a little bit at start up and it doesn’t spray oil when I’m cranking it over with the spark plug out so I’m pretty confused.
I know it’s probably the valve seals but I’m looking for some expert advice before I start tearing it apart. Any help is appreciated.
Use a ir temperature gun on the exhaust manifold ports, and start to find exactly which cylinders are firing and which are not, then look at every cylinder spark plug for oil, if the ones that don't have combustion have oil, but the ones that are firing don't, then that's probably not a problem, just find out why it isn't combusting. On a rebuild last summer I left a fuel injector unplugged, and for whatever reason, whether just the build up of tiny amounts of oil from the rings or whatever (new valves etc) that cylinder had noticeable oil in it, spark plug was oily and fouled. Plugged in the injector, ran it a while and all was good and normal afterwards.
Check your injector fuses and do the temperature test, of you don't have an ir thermometer, run it for 30 seconds, then use an eyedropper with a little water on each port, low tech but should work.
Right now I’m just trying to confirm that it’s the valve seals not the piston rings.
Is 125 psi ok for that engine?
Any help is appreciated thanks.
125 PSI is a decent compression number for a cyl... but IF there is an oil problem, the good compression could be as a result of the oil. The oil tends to improve compression because it fills in the gap in the rings. Seems unlikely though that it would be dumping that much oil... I'm thinking it's more likely a problem like what Patrick and 85 GT is saying.
I have an ir temperature gun so I’ll try and check to see which cylinders are firing but I still can’t get it to start so it might be kind of difficult.
Starting fluid didn’t do anything so I don’t think it’s a fuel issue but I’ll check it out this weekend.
