97 Grand Am crank sensor?

[razorbackGT]

hi everyone, this looks like a very helpful forum, so let's see what ya'll got on this.. here goes.. 97 grand am GT 3100(3.1) V6 SFI - 75500 miles

car was overheating and noticed coolant leaking from lower intake manifold. so me and my bro decided we'd just go ahead and take a step further and replace the gaskets all the way to the head gaskets (also did coolant temp sensor, new bosch plat 2 plugs, pcv valve, valve stem seals) did that, everything put back together, went to start her up, and she started up first try, idle a bit rough, but figured it just needed worked back in.... check engine light came on after second start, but figured it was just a stupid code that would clear up itself...

buttt... after a couple days and the light still being on, took her to autozone to get the code read.... turned out to pull up 2 instances of "p0336" - crank sensor "A" CKT(circuit) performance. so gas mileage is pretty bad (10-15mpg) compared to what it was before the job, and idle is around 1000rpm compared to normal 500ish idle. not only is the idle bad, but acceleration is crap, the car jerks repeatedly, yet i still pushed it to about 90mph just to test her out.. no stalls at least , so i can drive it still.....

fuel pressure readings:
30-35psi ignition on, no start
VERY erratic needle around 40psi running engine
45psi w/ vacuum removed from fuel pressure regulator(haynes manual says psi should drop 3-10psi when doing this?!)

Vacuum reading (at PCV hose) - needle shakes between 15-16 PSI (bro says isn't too bad for an older engine (75000 miles)

This is all the info i got. not overheating anymore. pretty sure code is referencing 24x crank sensor behind the harmonic balancer? let me know what you guys think please! thank you!

[xeroinfinity]

Welcome to AF!

For one thing those plugs arent the best and wont last you very long.

Double check your engine grounds. Like the injectors and Ignition coils. Make sure your plug wires are connected.

Might try cleaning you IAC & its port to clear up your idles issues.

On the p0336 I'd check both of these wires out from the sensor up to the top of the engine. As these would have been unpluged when you disassy the engine.
You can test these from the main harness on the top of the engine.

Not exactly sure right off on the stats, try this link for resistance values and voltage test procedures. Just scroll down to the bottom for your 3.1

Hope that helps.

[razorbackGT]

thanx for the reply, i will try what u have suggested and report back asap

are the bosch plat 2s really THAT bad , and why if i may ask? those back plugs are a pain in the arse , so i replaced them while engine was disassy, first time changing all the plugs since i've had the car (about 2 years).

[xeroinfinity]

Bosh arent made for the extremly hot ignition systems GM uses. They just burn up after 15-20k miles.

GM does recomend the AC Delco Iridiums which are $6 each but will last you 75-100k miles.

And GA's are easy to change to plugs compared to the Grand prixs 3.8L. You usually have to loosen an engine mount to tilt the engine to get to the rear plugs :banghead

hope that helps.

[Aki334]

I just wanted to add for Bosh spark plugs man I am pissed too (I was also against bosh platinum sparkplugs before) but I do not know what pushed me two days ago to buy and test Bosh 4+ them no difference at all, even worse misfire at my well known #3 and #4 cylinders. I will try to get myself new set of delco too. But anyway, if you decide to change your spark plugs the fastest way for 3.1l is to remove ICM housing bolts one 10mm bolt is 1" to the right of your MAP sensor, the second one is about 5" to the left of your sensor and two 13mm bolts are close to your sparkplug boots for 1,3,5 cylinders you will also have to take off the purge valve mount off in order to lift up complete ICM housing with ignition coils in place. I use 7" extention and 1/2 socket that fits tighter on 13mm so it will not fall out of your socket (nice tip once you get used to it you will be able to change them in 30 min.

[xeroinfinity]

S*** it takes 45+ min's to drop off those components alone.
IMO the 3.1, the 3.3 and the 3.4 you dont need to remove anything.

A good plug socket, 3" extension and a swivle will get them easily.
The rear two on the pass side you can remove from that side, the last one on the drivers side is easier to remove standing on that side.

It takes me about 30-40min to get all 6 with the engine hot or cold

BTW I do recomend using anti-seize on the threads of the new plugs

[razorbackGT]

have been checking wiring in my spare time, noticed a couple connectors with some corrosion(iac valve, iat sensor), so i cleaned them with some electrical contact cleaner(still no help, but doesn't hurt anything . my bro is borrowing my jack stands, so i can't change out my fuel filter which i've been wanting to change out. another thing i realized is that he didn't secure the coil assembly back down all the way, with only i think 2 of 4 bolts holding it down(1 on each corner). i don't think this would have any impact on the grounding or anything? also threw in some STP high strength injector cleaner for the hell of it. i wish i had a digital ohm meter to test wires with... i might splurge on one, b a good investment me thinks..the electrical grounds seem to be fine, i will probably clean IAC valve/port / throttle body tommorow. just thought i'd post somewhat of an update!

[razorbackGT]

got a digital multimeter(generic for 4$!, same as the motorcraft that is 20$), got wiring diagrams from haynes and autozone.com but i don't know what terminals "A and B" are as said on the link u gave me. also , i have no experience with electronics other than building and troubleshooting computers. so how do you "backprobe" connectors and what is required to do so? is it safe to use my 10A multimeter with battery connected? don't wanna blow the fuse or myself up! LOL! according to the wiring diagram, 24x sensor has 2 red and 1 yellow/blue - but not sure which is which.. ergh, o , and one more thing, when they say crank the engine, do they mean manually or by starting the car? thanx

[J-Mech]

Hey xeroinfinity! Had a guy call me out to his place one day, he broke one on the rear plugs on a 3.1!!!! DAMN like to never got that out

[xeroinfinity]

Originally Posted by razorbackGT

got a digital multimeter(generic for 4$!, same as the motorcraft that is 20$), got wiring diagrams from haynes and autozone.com but i don't know what terminals "A and B" are as said on the link u gave me. also , i have no experience with electronics other than building and troubleshooting computers. so how do you "backprobe" connectors and what is required to do so? is it safe to use my 10A multimeter with battery connected? don't wanna blow the fuse or myself up! LOL! according to the wiring diagram, 24x sensor has 2 red and 1 yellow/blue - but not sure which is which.. ergh, o , and one more thing, when they say crank the engine, do they mean manually or by starting the car? thanx

If you can build a PC you can trouble shoot wires.
To back probe you need something small and sharp.
straight pens(for sewing) work well. ALl you are doing is probing the back side of the wire connectors.
Sometime all you need to do is push the multimeter point into the back of the plug to probe the wire(s).

YOu should be fine using the multimeter while the battery is hooked up, other wise you couldnt get a volt/ohms/signal reading.
Ont he wire colors try to wipe them with water.
A solvent might work too, but could change the color of the wire.

J-Mech, that can be a pain!
Was he installing or removing the plug?
Breaking the top off isnt bad, finding the piece might
I've had them break the inside(threaded piece) off and the center came out. Easy-out my ass!

[razorbackGT]

thanx, i will get me some little pins and give it a shot, and if i never write back, i'm a smoldering pile of electrified goo in my driveway, lol!

[razorbackGT]

well, i'm not dead, i just got a replacement sensor and will be installing soon, and i hope to write back w/ good news....

[razorbackGT]

thanx for all of your help fellas, turned out to be a combination of things. me and my buddy replaced the 24x crank sensor. MIL went off for 5 min. and flashed back on, indicting a misfire. so i drove right to "the zone" and had the code scanned. came up, i believe p0306(pretty close to being the same as other code) I had replaced the spark plugs after doing the head. well, the plug on the #6 cylinder had a crack in the porcelain!! rushed right to parts store, got a replacement plug, and boom baby! also cleaned throttle body out, so now she runs better than ever!! my need for speed is now fulfilled once more! still have a new fuel filter and plug wires to put on anyways. now i'm once again focusing on mods (air intake, perf. exhaust). thanx again!

[xeroinfinity]

Glad to here you got it going !

[jonnybravvo]

i need help getting the power steering pump off my 97 grand am 3100 im replacing my intake gasket how do i tell if my head gasket should be replaced also already torn apart