Evildiesel

Hi all, since my 02 is still in the shop (hit a deer) waiting for a roadarmor bumper (going on 4 months now) and my rental time ran out, I went out and bought a nice 89 as a hauler and work truck. I have a few questions though. It has a pretty bad vibration at idle and the previous owner says its always done that. It gets worse with the AC on but goes away as soon as I step on the throttle. It gets so bad that the truck actually starts to rock back and forth. I was wondering if this was normal for the 89's or is there a fix. I know the transmission was just rebuilt but I know it did it before that as well. Any Ideas? Also, the brake and anti-lock lights are on all the time, is there a way to fix this? And finally, who sells low rev tachs (like autometer's) so I can get one and install it? Thanks for the help guys.
Evil

Alec

It sounds as though the truck is idling too low. Isspro sells a couple of tachs that will work -- either from an alternator tap, or from a crank sensor kit (the stock crank sensor didn't come on these trucks until '92) ISSPRO. The anti-lock brake control box is behind the glove box -- just open it past the stop -- and has a big plug with a wire bundle, and one little black wire coming off and ending with a spade socket -- if you ground that with the ignition in the on position (and the truck not running) the ABS light will blink a code. First blink is long, include it in the count. 9 is common, means a bad connection to or open speed sensor (on top of the differential housing). To reset the module, unplug for about 30 seconds (disconnects all power) to clear the memory, then plug it back in. There is a service bulletin with a new plug for the sensor, but it seems that if that is the problem and you clean and seal it up, it works okay.

Good luck,

Alec

Bushy

Yup,, first thing to try is crank up the idle a bit more.
I have mine set at 750 with trans. in "D" and AC on.

Bob.

ramguy

I have a 93 just unplug the module & you'll not have to deal with any of it. Rear ABS is redicouls in the 1st place.
60 percent (or more) of the braking on any 4 wheeled vehicle is in the front because of weight distrabution. Which means your front will be the 1st to lock up. :Anyway that's what I did to mine and I've had no more "Idiot lights" or brakes draging.
I spoke w/ a DC serviceman and he admitted that would give a normal brake system again.

ramguy

wannadiesel

Summit Racing sells the AutoMeter diesel tach http://www.summitracing.com/, and I agree that you should try turning up the idle a bit, as long as it's not creeping bad already.

Winr

[quote author=ramguy link=board=9;threadid=17774;start=0#msg166444 date=1059675921]
Rear ABS is redicouls in the 1st place.
60 percent (or more) of the braking on any 4 wheeled vehicle is in the front because of weight distrabution. Which means your front will be the 1st to lock up. [/quote]
Ramguy
You are correct about the brake bias but... the heavier axle will not lock up first, the lighter one will, hence the reason anti lock was on the rear. The brake bias (60%-80%) is on the front to take advantage of that weight, more pressure (weight) on the tires the more gription they have.

bigredbrick

Rear ABS seems like a good idea on dry or wet pavement.
On ice with the fronts locking up and the rears doing their thing is a strange sensation. It just don't feel right - never will get used to it!