Hey all, I am new to this board. I just bouhgt *back* an 87 GN that I had for 4 years, and sold last year. The owner took very good carre of it and hardly drove it, howerev a couple of things are bothering me-
1) the tach is at least 2000 rpm's off (it may even just read double). What should I check?
2) the factory boost led's stay on up to five psi and increse from there- what sensor does it get it's reading from?
3)the car "detonates"- HORRIBLY!! It isn't a typical "ping", it is a couple harsh "taps" coming from it right before it shifts. It is not a rattle or anything, nor is it an engine knock
.. Why would it do this? Any help would be greatly appreciated as I do not even want to drive the car until I get these issues squared away. Thanks in advance!!
Joe
The tachs in these cars are generally regarded as inaccurate. The boost guage gets its signal from a MAP sensor on the passenger's side fender. Since both readouts are giving you trouble, there may be a problem on that circut board. Casper's Electronics may be able to help you if that is a problem.
Hard to say what the knock might be. Anything from overboost to low fuel pressure, etc. More information from a scan tool and fuel pressure guage is needed.