I have an '87 coupe that I have done everything to. I'm at my wit's end, it still doesn't run right. The only 3 problems left are as follows. First, the front left brake sticks. I have replaced the caliper and pads twice and the hoses. My guess is that its the brake "thing" behind the drivers seat. I don't know what to do for it. Second, when I turn on the headlights at night the gauge lights go out. If I turn the lights back out they come on. It doesn't do this during the day. I replaced the headlight switch and fuses. Lastly, the intake manifold had an oil leak, so I replaced the seals. No more oil leak but now the car doesn't want to simply start. I timed it, but when I go to start it, it wants to die. I have to keep giving it gas until it warms up, then its fine and will start up after its warm. No mechanic around here can hook up a computer to check the code. What do I do other than just set this thing on fire. Any help would be appreciated. Thanks

 

Check the torque on you intake manifold bolts. Sounds like a problemed seal the cures itself after warming up. My '87 had the same problem with the lights but it was the switch. as for the brakes, perhaps the rotor is warped and grabbing. have it checked and if it needs turning be sure to do both sides. perhaps others with more knowledge will reply. Cheers.

 

The gauge lights going out at night when you turn on the lights sounds as if the photocell in the upper left corner of the dash,the small oblong window looking thing, might be bad. It senses the light and brightens or dims the dash, and if it goes bad, I think it may turn them off when the lights are on. As for the brakes, my right front does not want to release, and I have found by using a mityvac to bleed the brakes, that I cannot pull any fluid through the lines to that brake, the others work fine.I haven't found the problem yet, but I suspect a pinched,crimped or blocked line, or the separator block that separates the lines from two coming out of the master cylinder into four,two to the rear, two to the front.I have done all you have and even took the master cylinder apart and could find nothing wrong with it, disassembled the calipers, the whole nine yards. If I find my problem, I'll let you know what I found. As for the engine, maybe the throttle position sensor is out of adjustment. You probably had to take it loose when you worked on the intake, maybe a loose wire, something of that nature, don't think it's anything real serious.Hope some of this helps you.It takes a lot of patience and a lot of help from the great folks on this form to keep your sanity while owning one of these babies.

 

I thought about the gauge light thing and I did replace the headlight switch on mine, because it nearly burned my car, and after I put the new switch in, the gauge lights worked like they are supposed to. Also, I have determined that my brake problem is probably that thing behind the driver's seat, which is the abs pressure modulator valve and the control module for the abs. These are quite expensive, and I'm going to bypass mine and do away with the junky abs GM put on these things. I'll let you know how it works out. Keep informed on the gauge light deal.

 

I replied to you before that I was going to bypass the abs modulator valve on my '87. Well, I finally did, after having to make two brass tees for the brake lines. I have just completed testing the brakes extensively, and they work correctly now. I have regular power brakes, but they release the way they are supposed to. Hold the brakes, even on a very slight grade, put it is neutral, let off the brake, and it immediately starts rolling, the way it should.There are only five connections in the box behind the seat for the brake lines. The front from the master cylinder, and two going back to the left and right front wheels, one from the master cylinder for the rear wheels and one going out to the rear wheels. Take the left rear wheel off, and trace the brake line from the wheel and you will find a tee that splits the one line from the box behind the seat and goes to each rear wheel. The connections are metric and have a bubble flare on the lines, not the ordinary flare, thus I had to fabricate the tees as I stated earlier. Any machine shop can do this for you. My brakes finally work the way they are supposed to, and I'm going to put new pads on and try to enjoy this thing.

 

Collapsed brake line?

I've heard that many times, and can't see how a brake line 'collapses'. Hit the pedal, and fluid pressure HAS TO expand the line. So how's it gonna' collapse???

I did EVERYTHING, to find out why mine was grabbing right side, and sometimes left ('98 GMC). Even pulled the caliper pistons, and they had no dirt jam binding the bores. A fossil at the Advance / Zone said pull the section of line that goes into the caliper, and see if you could blow air one way, and not the other. HUH? You're kiddin'...

He wasn't. Both sides did the same way. The line is dual layer, and the inside line DOES collapse, and it acts like a valve when it happens.

Mine are free, free at last!!! Don't know if GM c4 also has dual layer-lined lines, but anything is possible.