Ok....My 86 GN is not running. I was going down the road..maybe 90mph and the car died. I got it home, did some basic test. I replaced the fuel pump (walbro 340) It was the stock pump and the pressure did not read well. Anyway I have been reading about the cam sensor and the Crank sensor...The crank sensor shows two bolts holding it in. I have taken them out and it will not come out. Am I missing something?? The illustractions show only two bolts. The bolts where loose when I took them off. I was getting some backfire, but it was not cranking. I figure it is a few things, but I can't get the crank senser off to start. Help please. I have had my car since 1992. NO other mods except hooker exhaust and trasher 93 chip..wastegate..boost gauge. Nothing else..and its obvious I can't until I get it running...Thanks in advance..Ken you usually respond..Thanks in advance you have been a big help in the past
Sorry - i posted to the list about checking the starter and alternator first since they are easier.
Im not aware of how to easily test a crankshaft sensor using a multimeter and/or common tools.
If you've eliminated the easy targets (loose starter, alternator, shorted power on passenger header/ground issues), then someone with crank sensor-testing experience will be able to nail this for ya. Im curious as to whether the car just "shut off", or gradually sputtered, and misfired, hesitated first - if so then sounds like you're on the right track. I just want to make sure you're not jumping ahead of the basics first...i'd check the sensor last since i believe you'll need a special tool to test the sensor properly.
well - you've already shined the light above Gotham...im sure Batman will heed your distress signal in due time...probably heading out to the Batcave as we speak..
;)
Good luck.
Jay,
I was passing some slower vehicles(HA>>HA)..and the car just shut off..no spits no sputters..just Off. All of the connections seem fine. The engine cranks fine, it backfires every so often when cranking. When I put the test light on the wires to see if spark is happening it is only tripping the light when I get a little pop or backfire.
Thanks again for any help...Paul
I don't know if there is a way to really check the crank sensor and I don't think there is a tool you can buy. I'm sure if you have an Oscope or something similar (and the know how of what to look for) you could test it. In my experience, if you are having spark problems, ie no spark, it's almost always the crank sensor. Afterall, it's what gives the signal of when to fire. You said it was loose already?? It shouldn't have been, it's supposed to be set at a specific place and even needs to be checked for clearance. The crank interrupt ring goes between two of the slots, and that's what sets off the sparking. While taking off from a stoplight one night my car just quit and wouldn't restart. After a few days of working on it, I finally checked the crank sensor. It was there and tight but I pulled it off and found it was broken. Something must have flew up and smacked it, cracking it. My car would crank and crank and crank and then BOOM! I dunno if the broken part was hitting the ring every now and then making it send a signal or what...scared the hell out of me. I changed the crank sensor and vroom...back to the monster it is.
If I remember right, there is one nut/bolt that kind of pulls two pieces together (think a U with a bolt on the open end) that holds the sensor in the mounting piece. The mounting piece has two bolts in it that hold everything to the block. It does take some work to get them out if you're not familiar with them, not to mention you have a nice amount of room under the car. Even though(for some reason) I don't follow my own advice, I'd get an extra one to have just in case, cuz when it goes, it usually just goes...and you're dead on the road and probably up the creek trying to find the part. Check it out and let us know what you find. Then we can go from there if it doesn't fix your problem.
I have been able to check the crank sensor on some GM vehicles be using a "Node" light. It plugs into one of your injector connectors. While cranking the engine, the light should pulse. If it does, that usally means your getting a crank pulse. This node light is made to check if your getting a signal to your injectors. Usallly you get them in a kit that fits different injector connectors. There is about six of them in a kit. If you can find a Snap On or Mac tool person in your area, they should have the one you need. It is something to to keep for a quick check. Hope you find your problem,Tom.
I've got the bolts out..I can't get the sensor out. Do I pry it with a screwdriver or should it come out by pulling on it.
Thanks--Paul
Which part of it is stuck? I'm trying to remember how mine looks, and I'm not sure but I think they redesigned it, so mine may not look exactly like yours. If you loosen the small nut, the one that pulls the two pieces together and acts like a clamp, then the sensor *should* slide back and forth since that part just has a groove cut into the sides so it can slide back and forth. If the bracket is stuck to the engine,(ie bolts out and it didn't budge, possibly grimed up) then I would try to lightly pry on it, it's probably cast aluminum and could break if you pry too hard. If everything is loose, ie you can slide the sensor back and forth in the bracket, and the bracket isn't stuck to the motor, ie it just bounces around, then you're going to have to spin the crank around(by hand) until you get one of the interrupt rings over where the sensor sits. That should give you the extra clearance you need and it should pretty much fall out. Before you pry on anything, (ie bracket) get one of the interrupt rings over the area the sensor is at, that way if you pry too hard and it all pops loose, you have a better chance of not smashing the sensor into the ring. Afterall.....we're not 100% the sensor is broken.
If you pry it into the crank ring...well then I'd say it'll be 99% that it's broken.Good luck
Your sensor bracket goes on a dowl pin that also comes through the timing cover. Looking from the front of the car , you can't see it. Its between the two bolts that hold the bracket on. With the two bolts out, you should spray it with some penetrant (WD-40), and twist it while pulling out. The pin is steel and the bracket is alum. so they corrode and get stuck. Good luck
Ken
87 GN
DOH! Oops, I forgot all about that pin. But gently prying should get the bracket loose. If not (depending on the condition of everything down there), twisting on it will get it loose, just might take some effort. And with the mention of that dowel pin, I can't remember if it was this pin(pretty sure it was) or another(can't think of where) but I had to slightly cleanup the edge of the hole, ie casting flash, and I did my best at trying to smooth the pin as well, one of them had a burr on it, to get the new one to slide onto the pin. You don't want to try and force it with the bolts because it's alum and could get bent/broken easily. I got mine to where it would slide on easily until it hit the cover. It's kind of funny how the mention of something can bring back a memory(dowel pin = pain in the ass, had to use a file.) Let us know what happens.
Scott