troubleshooting my 92 Legacy SS

[sliverumble]

Was driving my legacy today and then the issues started. I tried to get into boost and there was hesitation and acted like it wasnt getting good spark when I was only boosting maybe 2 psi. As I drove further the car ran like crap and acted like it was only running on maybe 2 cylinders, so I then pull over and pop the hood, everything looked normal, boost lines and vacuum lines looked to be connected. I tried to start it a couple of times and it started after multiple cranks but idled horribly and wouldnt stay running. I havent looked at it real close yet but I think its a spark issue. I have replaced the plugs, probably wouldnt be a bad idea to do new ones again, and the wires far as I know havent been replaced in some time. Anyone have a different idea what it might be?

Please advise,
Thanks Grant

[kimokalihi]

Could be anything. Start at the basics. Check your ECU for codes. This should always be your first move. It's the easiest thing to do and it can save you a lot of time. Don't guess, diagnose. If there aren't any codes start checking for spark, then fuel, then compression, etc. Don't replace the plugs and hope that fixes your problem. Disconnect your fuel pump at the pump (electrical connector, not fuel line) and pull the spark plugs one at a time and plug them into their wire and ground the body of the plug on the engine and crank it to see if there's spark and if it's strong or weak. Also check the plug gap. .039-.043" is within spec. At the same time as you're doing this you might as well check compression. Have someone sit in your car and press the throttle open all the way and crank it to check compression on each cylinder. I don't remember the specs off the top of my head but probably 175ish is good.

If that all checks out, check your fuel line for fuel. Pull the hose off that goes from the filter to the fuel line on the intake manifold and see if a strong flow comes out when you hook the pump back up and turn the key. If you have a fuel pressure gauge, even better.

Then continue on to the coil pack and other electrical such as the engine harness and injectors, etc.

[sliverumble]

thanks for the advise. do I have to count how many times the cel blinks or can I use a scanner to see what code comes up?

[snailslow]

count the cells.. make sure the maf is plugged in, and that u dont have a boost leak.. that will cause that. and the comp should be around 150 or less.. mine was all around 140

[Legacy777]

I would also suggest you check for boost/vacuum leaks? That may be another culprit, and/or possibly a bad MAF sensor.

[x2hawt4ux]

sounds like a maf problem to me

[kimokalihi]

Official compression specs for 1st gen legacys directly from the FSM.

Non-Turbo

Standard - 156-185 PSI
Limit - 128 PSI
Difference between cylinders - 28 PSI

Turbo

Standard - 142-171 PSI
Limit - 114 PSI
Difference between cylinders - 28 PSI

[kimokalihi]

So I was pretty close

[sliverumble]

Yeah you were close