Let me preface this post by saying..... I've posted this question in the truck forum on Chevytalk... and have had little response..... and since most GM cruises.... from the same era automobile.....are probably very similar....... I thought I would try a "high traffic" message board such as this one.......... for the camaro's.....


I have a '97 Silverado..... and a '89 S10 Blazer that has the same cruise malfunction...... after awhile...... it will just start to coast.... just like you were pressing the coast button....... and when you hit the accel button...... it doesn't do anything..... it might stop coasting.... but usually won't accelerate.......All this happens without rhyme or reason.... it might not do it for several hours while on cruise.... and then all of a sudden...... it starts this funny business.....



Do any of you F-body guys have ever experienced a crazy cruise like this one? Any suggestions would be helpful.

 

Sounds like your coast switch could be shorting out? Might be the cruise controller or lack of engine vacuum (the blazer requires engine vacuum stored in a vacuum ball to work, on a long grade the supply could become depleted as it manipulates the diaphram). I have 1983, 1984, 1988, and 1997 GM vehicles and haven't ever experienced your problem. The problem I have is the 83 will lug down a few miles an hour, then all of a sudden gun it to WOT when cruising, speed up 10-15 mph, then maintain the 10 mph faster speed (I don't know if it is the cruise, carb, transmission, gearing, or something else???). My 1984 chevy van has the best cruise of them all except it will quit occasionally when pulling heavy trailers on long uphill grades, which I believe is from lack of vacuum..

 

vaccum leak or bad actuator