Running rough after freshen up. Cam sensor?

[Mike70gtx]

Just got motor in and fired up. At first I had some some valve train noise and about about ran an ad for the car. I had a friend come over to listen. After several start ups and a few minutes running, it quieted down. I guess there was a lifter that took awhile to get some oil. I don't quite uderstand the whole preload stuff. I put the lifters and pushrods in the same place as I took them out. I had no problems before. I am going to go back and check all my hoses and wires. If I didn't set the cam sensor right, what kind of symptoms would I have? I want to try to eliminate as much as possible in my house on the computer before I go back out in the 105 degree Texas heat.

 

[Daniel Jost]

did you set it with a cam sensor setting tool? i tried it with the precetures in the gm manuals with little luck, and got a setting tool and what do you know its exactly on!
I need more detail of what is rough running, missing,bogging,popping? or maybe some video of it?

,dan

 

[Mike70gtx]

I thinking that I might have set the cam sensor wrong. I put the masking tape (1.45") from the dead center mark counter-clockwise (toward the left)on the crankshaft. Would that make it BTDC instead of ATDC?

 

[Mike70gtx]

I read the instructions again. I think the tape is on the right side. But I turned the camsensor the wrong way to get my voltage to drop.

 

[Mike70gtx]

Help! Just re-did the cam sensor setting and have same symptoms. It runs rough and rich. Plugs looked fouled. With the cam sensor at tdc the window is pointing towards the headlight on the drivers side.Does that seem right? I set it as per instructions with a volt meter. What else could be the problem? Car was running fair before motor was pulled. It should show in my signature that I have a trans plus with extreme chip.

 

[johnnyttype]

u may have the sensor 180 degrees out. even though the car is at tdc it could be on the power stroke, not the intake stroke like it needs to be. crank rotates twice per one rev of the cam. when engine is at tdc, intake stroke, window should point towards the front of the car i believe.

 

[Mike70gtx]

I got it on the power stroke. It was pushing air out of number 1. The window is a little right of pointing to front bumper. I let it run long enough last night to warm up. It just runs a llittle rough and when you step on it a little it will miss and backfire some. It's not terrible, but something is not right. I did have some valve train noise on initial start up. I hope something didn't bend.

 

[mikestertwo]

It doesn't make any difference where the window in the cam sensor is facing as long as you timed it correctly. Make sure you are turning the sensor counter clockwise when you are looking for the high to low transition. Did you check to make sure you had all the plug wires on correctly? Translator settings correct? No leaks anywhere between the MAF and the intake?

 

[Mike70gtx]

I've checked most of the basics. Did find one vacuum line off and plugged it, but no difference. I'm wondering if something went wrong before I pulled motor. It ran fair at the track the day before but it looked rich on scanmaster. So I leaned the trans fuel setting from plus 12 or 14 down 2%. When I got on it pulling on the interstate it backfired. I eased up and tried again to pass someone and it back fired again and that's when I blew the head gasket. My maf is a 3.5", used and without screens. Most everything else is new. I did have to send my translator in one time when it malfunctioned.

 

[NEWCHAPTER]

Where did you get your new cam sensor from because its sounds like everything that i am gettting... kind of rough idle and missing/hesitating under some acceleration. The engine quit and I thought I had a bad camsensor and replaced it with one from Kirbans but that was not it it was the crank sensor got that fixed and it now acts like that

 

[Mike70gtx]

The cam sensor is not new and I don't really know the history. I should probably have a spare. Where is a good place to get one? I wasn't sure if it would produce symptoms like this or just not work.

 

[NEWCHAPTER]

just doing some fishing for knowledge as I cannot figure out this problem.... I did the top engine clean and in the middle of it the car just quit and wouldnt restart... so I thought maybe the camsensor ( which is was the crank sensor)I had purchased a new one from Dennis Kirban and put on the caspers led cap , it runs but not very well , it bogs down if you give it some gas... so I didnt know if you had replaced yours or not

 

[Mike70gtx]

Just ordered a new cam sensor cap from Caspers. They now have one with a built in light to set it. You just put it on tdc and set the light.

 

[johnnyttype]

I got it on the power stroke. It was pushing air out of number 1. The window is a little right of pointing to front bumper. I let it run long enough last night to warm up. It just runs a llittle rough and when you step on it a little it will miss and backfire some. It's not terrible, but something is not right. I did have some valve train noise on initial start up. I hope something didn't bend.

i think u may still have it out 180 degrees, u do not want the power stroke when setting the cam sensor, u want the intake stroke. once u have it on tdc of the intake stroke then u rotate 25 degrees and adjust the cam sensor.

 

[Mike70gtx]

I hope that's it. All the instructions I read say to get the #1 cylinder to push out air, meaning valves closed. Then I started with the window of the sensor toward driver's fender and by the time it goes in, it then points to the drivers headlight. Everything looks the way it did before I took it apart. My voltage wasn't very consistent with my makeshift voltmeter setup. The cap I'm getting will have a light built in to set it.

 

[johnnyttype]

yea i used the caspers box and that was real nice! a nice little trick i found out when messing with a cam sensor, if ur gonna pull it out, get engine at tdc, scratch a line in the cam sensors housing when cap is off that is at the edge of the window on the sensor. its alot like pulling a distributor. when reinstalling the sensor, make sure engine is at tdc install cam sensor and then just line the scratch mark up with the edge of the window by spinning the housing.

if u want to u can take the cap off of urs, loosen the hold down bolt and spin the housing 180 degrees and see if it makes a difference. unless u can just flip the cam sensor cap around, cant remember if it only goes on one way or not. if not just spin it back and set the sensor with ur new cap with LED when u get it.

 

[mikestertwo]

i think u may still have it out 180 degrees, u do not want the power stroke when setting the cam sensor, u want the intake stroke. once u have it on tdc of the intake stroke then u rotate 25 degrees and adjust the cam sensor.

You set it on the compression stroke 25*ATDC not 25*ATDC on the exhaust stroke. If the cam sensor was 180* out the engine would not start. It will usually try to run backwards when you try to start it if it was 180 out.

 

[johnnyttype]

my bad it is the compression stroke, probably just confused the crap out of u buddy!

ive read several times about cam sensors being 180 out and running but very poorly?

 

[mikestertwo]

I've checked most of the basics. Did find one vacuum line off and plugged it, but no difference. I'm wondering if something went wrong before I pulled motor. It ran fair at the track the day before but it looked rich on scanmaster. So I leaned the trans fuel setting from plus 12 or 14 down 2%. When I got on it pulling on the interstate it backfired. I eased up and tried again to pass someone and it back fired again and that's when I blew the head gasket. My maf is a 3.5", used and without screens. Most everything else is new. I did have to send my translator in one time when it malfunctioned.

I missed this post about the MAF. Have you tried another MAF? Running without screens is a no-no. Removing the screens upsets the calibration of the MAF. Try another known good MAF that has the screens in it and make sure your translator settings are correct.

 

[Mike70gtx]

I've been running that maf for over a year with no problems. I did start getting some popping between 2nd and 3rd gear at full throttle. I'm going to get a new one to make sure. I've always been a little unsure about the no screen deal. What can I watch on the scanmaster to see if maf is working? I didn't chance anything on the translator, but went back and checked the settings.