91Voyag. 3.3 test cam, crank sensors

Wow! Am I glad Im here. Learned a lot just reading. Figured I better register.
OK, 91 Voyager LE, 3.3 v6, w/ AC
Like a lot of posts Ive read, mine will not stay running. Started 2 nites ago. Will start fine and idle smooth then just shut off. Or sometimes, continue to idle for 2 min, 20 min, or even all day.
Also, if we try to drive while idling fine, will take off and get 2 feet, or sometimes 10 feet or sometimes 2 miles or even all the way home(25 miles from civilization). And, sometimes, wont start at all.
Took it to dealer service. Charged me $70 for diagnostics check. Told me bad coolant temp sens(for computer not guage), gummed up throttlebody needed cleaned out and possible problem with ignition switch(hmm......just replaced that, brand new). I won't tell you what they were gonna charge me but I'll tell you I ran to the parts store 2 blocks away and got the temp sens for $9. Anyway I swapped the temp sens out in the parking lot cuz they told me that was the main cause and would probably get me home(25 miles). Got 4 blocks and shut off. Went back to dealer and inquired for some more information and basically just got attitude. Went back to parts store and got some gasket material and brakeclean for the throttlebody and also got a fuel filter for good measure. Had some friends following me so limped on home. Cleaned throttlbody and reinstalled with my new custom built gasket(first time). No start, now. Suddenly had a revelation. Decided to see what the spark looked like which, like a retard, shouldve already done. Anyway, no fire out of two wires. Then on one crank attempt, saw a tiny spark and van fired up and now had spark. Idled for about 20 sec and died. Then van would start, then wouldn't. Played this game a few times bouncing one wire between plug and flathead screwdriver. Dug thru Haynes a lil more looking at coil pack, cam and crank sensors. Obviously we're heading in that direction now. Need to check resist on coil pack. Will do it tomorrow. Dark now. Also gonna change fuel filter tomorrow but we're leaning away from fuel anyway, but it probably needs it. Can those coilpacks progressively go bad or just GO? Also is there a way to test the cam and crank sensors?(Haynes jsust says replace) Any other sensors or areas to check? Any other ideas? THANX TO ALL OF YOU RITE UP FRONT!!!!

OK, I checked coil pack. Each secondary is a lil more than 12K ohms. Within range. And all 3 primary show 0.7 ohms. Except Haynes book says should be between .52 and .62. O_o But the illustration photo shows them testing one and on their meter it shows 0.8 ohms. Is a lil over .62 ohms OK? Are we looking for dead short or open? Im guessing coil pack is OK. Or at least in its current state. I still need to know if they progressively go bad or just GO. Also, I found the cam and crank reference sensors. I would still like to know how to test them. What to look for on my meter. If even possible. Im 25 miles from anything resembling a parts store. Stranded basically. Will probably have to hitch hike to parts store to get what parts I need. I also can't figure out which relay is ASD. I got 3 relays next to batt. None of haynes's pics show exactly mine. OK, Im gonna go do the fuel filter now and put the coil pack back together. If anyone knows the answers to my questions, please reply. Im really in a desperate time AND MONEY crunch here. thank you ALL!!! I will leave this online and check back every few. Thanks!!!!!

***EDIT- Just wondering if this is correct. Haynes says, as I understand it, that there are basically only 2 things that will trip the auto shut down relay on the 3.3L, cam ref. sensor and crank ref. sensor. If either signal is missing when in the run position, then the ASD relay interupts power to fuel pump, injectors, coil pack and heated oxygen sensor. Does this sound correct?? Does anyone know if there are any other sensors that will trip the ASD relay?? I dont mind just replacing both sensors. Just an issue of distance to parts store. Im the kind of person who likes to actually test and verify the integrity of a part before replacing it. But as I said, Haynes doesn't say how to test them or what kind of signal Im looking for. I would hate to limp 25 miles into town, get the sensors, limp home and replace to find out it is still messed up. Anyone know??
AGAIN, THANK YOU IN ADVANCE!!!!!!!

Well, I have the 2 sensors on their way. Still would like to know for sure a way to test them. Also, does anyone have a schematic of this system including the ASD relay, cam and crank sensors and coil pack plug, that is current for my year and engine?? Haynes book doesn't. They're usually pretty general about the schematics. Would be nice to have description of exact wire colors and function. If replacing these 2 sensors doesn't solve it and ASD relay is good, am I looking at a new brain????? God I hope not. :(
Thanx again!!! :)

Boy Taz480 you really are frustrated an I don't blame you. If you have a 91 and the CPS and Cam sensor are originals then they probably need replaced anyway so save time and just replace them. As for the running part, if you don't get it running after that then look at the fuel pump relay. It will shut a vehicle down as it causes the fuel pump to quit and when the car stalls it will reset and run for a while longer. As for the coil issue they usually go gradually but they can go all at once.

The only other thing that may be causing your problem is a bad ECM. Don't waste your money on a new one try one from a wrecking yard as it will save you a bunch and most give at least a 30 day warranty on them. Good Luck and welcome to the forum!

I am having the same problem. My car gives me the diagnostics code p0300(injector misfires) also. I had prior problem like that one and had fixed it with a new ecm and crank shaft which with work cost me $700.
And now just 5 months later I am having the same problem. So an a new ecm may not be the problem at all.

Thanx for replying guys, and please, call me "Taz". My step dad brought me the sensors. Im gonna put em in in the morning, one at a time, starting with crank ref. sens. I have a new question, tho. The cam sens. came with a paper spacer but crank sens. didn't. Is this a big deal? Haynes book says it should have a paper spacer. But I usually like to leave new parts alone. I figure they come the way they're supposed to. Is the paper spacer necessary? If I don't use one, will it cram up against the drive plate and tear it up? Further, if it is necessary, anything wrong with using some regular old 1/16 inch cardboard? And what would I adhere it with?? Would super glue eat the plastc or damage the signal? The old crank ref. sens. came out with no spacer. Just out of curiosity, what happens to the paper spacer disc if it falls off? Just floats around in the motor? Anyway, I would kinda like to hear back before morning, but if I don't, Im gonna put the crank sens. in w/out the spacer. Hope that's right.
As for the other part, fuel pump relay? Is that the same as the ASD relay? The ASD shuts down the fuel pump if the crank and cam signals aren't there. How do I identify which are which by wire color? Haynes schematics suck. I only have 3 relays next to the battery. As for the brain, ya, I already been to the dealer once. I dont wanna go back to have the computer programmed. Anyway, lets just try to not go there yet. Eeeeek! I'll post back in the morning. Thanx guys!!! :)

***EDIT- Sorry, forgot. In reference to fuel, if what you call fuel pump relay is the same as what Im calling auto shut down relay, then yes it could be that. But it also will if the brain doesn't see signal from the cam or crank sensors, therefor doing it's job. In essence, the relay could fail itself shutting down the vehicle without cause but most relays either fail by welding closed or the coil is fried making the relay completely inoperable and stuck in the open position. I just dont know if things are connected to the normally open or normally closed(87 or 87a) position. As for fuel pressure, I can stick my finger in the schrader valve on the fuel rail and shoot fuel clear over the back of the van. I think pressure is good. :) But if it is a seperate relay, i would still like to check it. Maybe you could help me figure out where it is. My understanding is that the 3 on the left fender are A/C clutch, radiator fan and ASD(auto shut down). Sorry my posts are so long and contain so many questions but hey, that's how we learn, right? Plus I like to troubleshoot and diagnose in a methodical manner.

Just about to go out and put in the sensors. Im a lil more concerned about the lil round paper spacer issue. I dont wanna put it in w/out the spacer if its gonna ruin the sensor and I dont wanna put it in with a home made lil cardboard spacer if its gonna fall off and damage the tranny. Can anyone advise me real quick??

:confused:
I wish the reply rate was a lil higher here. :lol:
No matter, I still love this site. Ive learned a lot researching here and a few other places. Even before I registered.
Well I think I got it. Lookin like the cam sensor. replaced crank sensor fiest, deove around for a while and got home it died. Replaced cam sensor and drove all over the place, stopped, idled, backed up, pulled forward, idled, shut off, started, idled, drove around, idled, reved up, idled, drove, shut off, idled, reved, drove.....you get the idea. Seems to be good. Another thing I noticed, all this time Ive been getting a lot of smoke out of exhaust, not like oil smoke, just cloud smoke like when its really cold out and/or ur timing is off. This was with normal driving and even idling. After replacing the cam sensor, NOTHING out of tail pipe. Not even when I flat got on it. Makes sense cuz its the cam sensor that tells the computer to advance the timing if its off. Ayway, thanx for ur help. I think I finally got it. Hope my experience helps others. I'll be keeping an eye on it in case its just fooling me. Thanx!!!!!!!!!

sorry but i may be a little late but it does sound like you narrowed it down cam and crank sensors are a very common fault with this vintage and engine combo also just make sure the harness at either sensor is shorting or close to potential shorting areas also coolant sensor you replaced was it a 2 wire or 1 wire sensor?

sorry but i may be a little late but it does sound like you narrowed it down cam and crank sensors are a very common fault with this vintage and engine combo also just make sure the harness at either sensor is shorting or close to potential shorting areas also coolant sensor you replaced was it a 2 wire or 1 wire sensor?

Hi thunder!! Thanx for posting. Ya it took me a couple days due to innability to obtain parts and because of cold weather but I nailed it I think. I am in no way any kind of mechanic but I have had pretty good luck fixing cars with my Haynes manuals and the internet. :lol:
I even learned how to change out my head gasket(a pretty big job) on my '95 Geo Metro by just following Haynes and good people like you all.
Ya we went into the city, about 70 miles one way and home again. So after about 140-150 miles without a lick of trouble. I guess its safe to say I got it. Yes I doublechecked the harness' on both sensors. As I said, I am very methodical(at least I try to be). :icon16:
As for the coolant sensor, the one the dealership said was bad(which Im not 100% sure was true) and I replaced was the 2-wire below the coil pack, the one for the SBEC.
1-wire??? Are you just reassuring I changed the right one?? LOL! If so, thank you! Its always really easy to get things like that mixed up.
Actually I know quite a bit about electrical because of my work. I have spent about 10 years building and servicing luxery motorhomes. So Im glad it turned out to be electrical. LOL!!!!!
THANK YOU EVERYONE!!!!!!!!! I will definately be back around if I have future problems. THANX!!

it's good people like you that makes this forum give a good feeling when helping out you are not lazy and not afraid of doing things or trying and smart enough to tackel most mechanics worst nightmares
as lots of them seem to shy away from electrical problems {that is my specialty }

it's good people like you that makes this forum give a good feeling when helping out you are not lazy and not afraid of doing things or trying and smart enough to tackel most mechanics worst nightmares
as lots of them seem to shy away from electrical problems {that is my specialty }

LOL, mine too. :biggrin:

Thanx again! I'll definately be back when I need help.

EDIT, wrong thread.

It sounds like you are have solved your problem with the cam sensor and hopefully mine as well. I do have one question. Where is the dang thing?

Found this on the free Autozone Online 1997 Haynes manual. It's awkward to find what you want, but the info is there, complete with diagrams.

On 3.3L and 3.8L engines, the camshaft position sensor mounts to the top of the timing case cover, in which the bottom of the sensor is positioned above the camshaft sprocket.

3.3L and 3.8L Engines

Disconnect the negative battery cable.

Detach the electrical harness connector from the camshaft position sensor.

Unfasten the camshaft position sensor mounting bolt. There is a hole in the bracket for tool access to the sensor mounting bolt.

Rotate the sensor away from the engine block.

Pull the camshaft position sensor up out of the chain case cover. Do not pull on the sensor wire.

There is an O-ring on the sensor case. The O-ring may make removal of the sensor difficult. A light tap on top of the sensor prior to removal may reduce the force needed for removal. Inspect the O-ring for damage and replace if necessary.

To install:

If the sensor removed is going to be re-installed, clean off the old spacer on the sensor face. A new spacer must be attached to the sensor face before installation. If the sensor is being replaced, be sure that a paper spacer is attached to the sensor face and an O-ring is positioned in the groove of the new sensor.

Apply 1-2 drops of clean engine oil to the O-ring prior to installing the sensor.

Install the sensor into the chain case cover and rotate into position.

Push down on the sensor until contact is made with the camshaft gear. While holding the sensor in this position, install and tighten the mounting bolt to 10 ft. lbs. (14 Nm).

Attach the electrical harness connector to the camshaft position sensor.

Connect the negative battery cable.