Help with 200s - Performance suddenly went to crap.

[rally4x4racer]

i have a compression gauge from HF and it wrks OK - I also have one that I bought from somewhere else? that I always use. I paid maybe 30$ for the better one and it has all the fittings to thread into different plugs. I love harbor freight - but youll use the gauge many times over if you tinker - get a decent one so you don't have to upgrade!

[1984 200s]

rally4x4racer ,

Where did you get your compression tester from?

Also, I just noticed that you are in Harrison, AR. I am a native Arkie (Fayetteville)that's living in TX. I really miss it - Arkansas is a great state (especially the NW corner).

[timmyhart14]

I had just about the same problem as this onetime, I was toping my 82 200 bigred out on a gravel road, full throttle 5th gear and suddenly it started running like crap, and popping, at idle and mid throttle it would run just fine, i checked every single thing i could think of, It was time for a rebuild anyways so in the time of disasembly, taking the valve cover off i discovered a broken inner valvespring on the exhaust side and marks and pits all over the exhaust lobe on camshaft. i dout this is your problem but its just something to think about and to let anyone know that this kinda thing can sometimes be the problem, reason for running good at idle and mid throttle was, outter valvespring had enough strength to make valve close in time, but once it reved up higher, there was not enough spring strenth to close the valve fast enough giving me valve float and makin some noise, just a thought