Tach not working properly. Reluctor ring?
Tach not working properly. Reluctor ring? I recently did an engine swap for a guy for a 347 forged LME motor. Well everything is perfect except for the fact the tach will only rev to about 2800rpm then it will go to 0 and sit until the car reachs back idle where it will then pick back up. I figured no problem, its a bad ground. Ive redone/checked every ground on the motor and its still doing the same thing.
Ive scanned the car with HPtuners and get two cam postion sensor malfunction codes. I pull the intake swap out the sensor clear the codes and it comes right back with the same codes. None of the wiring is pinched in the bellhousing, ive checked that. Ive checked everything I know to check and its still not right.
I was told that maybe the reluctor ring on the crank is bent or out of place. I guess its possible beings the crank is a stock crank that was reused but machined 1st. Or maybe the shipping knocked it out a tad. I was told that if its off or bent it would do exactly as I described. It seems to run a little rich at idle but not bad, its hard to start, you can turn it over a couple secs before it will actually fire, then sometimes it want fire and acts like its flooded. Its got a bad surge/miss 4500rpm and up almost like its starving for fuel, but according to my logs its dead on the money with the AFR.
After I completed the install, I tired to do a crank relearn but as soon as the tach would stop it would give me an error message so i was unable to do the relearn. I tried I know 50 times or more.
It just doesnt make sense, can anyone else think of anything that I could try, or check before I start pulling the motor back out? I know it prolly want work but Im going to pull the crank position sensor out and swap it just a try. If you have any suggestions postem up.
Ive scanned the car with HPtuners and get two cam postion sensor malfunction codes. I pull the intake swap out the sensor clear the codes and it comes right back with the same codes. None of the wiring is pinched in the bellhousing, ive checked that. Ive checked everything I know to check and its still not right.
I was told that maybe the reluctor ring on the crank is bent or out of place. I guess its possible beings the crank is a stock crank that was reused but machined 1st. Or maybe the shipping knocked it out a tad. I was told that if its off or bent it would do exactly as I described. It seems to run a little rich at idle but not bad, its hard to start, you can turn it over a couple secs before it will actually fire, then sometimes it want fire and acts like its flooded. Its got a bad surge/miss 4500rpm and up almost like its starving for fuel, but according to my logs its dead on the money with the AFR.
After I completed the install, I tired to do a crank relearn but as soon as the tach would stop it would give me an error message so i was unable to do the relearn. I tried I know 50 times or more.
It just doesnt make sense, can anyone else think of anything that I could try, or check before I start pulling the motor back out? I know it prolly want work but Im going to pull the crank position sensor out and swap it just a try. If you have any suggestions postem up.
I've had a similiar problem and the cam sensor was bad. I've seen them not complete the relearn if the code was stored in teh pcm for the crank or cam sensor. Clear the codes and then immediately try the relearn. Hope that helps.
I have a similar problem With an LS2 swap. I can read the RPM's with EFILive but the tack doesn't work at all. Also I get the cam sensor error. When I turn on the ignition, all the gages but the tack go to full and back, as a self test I assume. I was told that the wiring is wrong and to swap the wires til I get it to work. did that but no go.
HELP!!!!!!!!!!!!!!!
Al
HELP!!!!!!!!!!!!!!!
Al
Well this was an LS1 swap, the cam sensor wiring wasnt messed with at all. Ive got a crank sensor on order just to check it. I have a feeling its not the problem, but its worth a shot so I can rule that out.
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Originally Posted by STKN1STGEAR
you said that you scanned the car with hptunner, Did you read the RPM through the software? I can read the RPM on mine through EFILive just not with the tach on the dash.
Al
Al
Careful your timing set hasnt come loose... I had this happen. With a loose timing set the cam can walk around a bit. At idle it might sit with the reluctor groove lined up with the sensor, but when you give it gas, it might pull forward or push back out of line. Its worth doublechecking before it eats the motor.
Originally Posted by GuitsBoy
Careful your timing set hasnt come loose... I had this happen. With a loose timing set the cam can walk around a bit. At idle it might sit with the reluctor groove lined up with the sensor, but when you give it gas, it might pull forward or push back out of line. Its worth doublechecking before it eats the motor.
Now that mentioned above about the Hptuners reading it, it has me wondering. If the cam was walking or the sensor was bad, or the ring was bent then why would the Scanner still pick up the RPM's but not the tach?
Originally Posted by GuitsBoy
The HPTuners scanner reads from the crank sensor. The tach is driven by the cam sensor. FWIW, When my cam walked I had a cam sensor high signal error.
Originally Posted by Z'mnypit
Why and how did your cam walk? Did it do any damage?
Originally Posted by GuitsBoy
Cam walked because I had used old loctite. My guess is that it wasnt properly sealed or had a leak and the tube of red loctite catalyzed somewhat before application. I made sure to clean the bolts and holes with brake cleaner andthen torqued to spec. After a couple hundred miles the bolts loosened up and backed out about 1/8 - 1/4 inch. It threw the cam code and the tach stopped working. I took it apart the next day and luckily caught it before the lifters rolled off the lobes. I tightened the bolts back up with new loctite and they were fine for 20K miles until the next cam swap.
You did check for any garbage stuck to teh magnetic tip of the cam sensor, no? Maybe the reluctor was ground incorrectly? Match it up to the stock cam to make sure it wasnt ground off target.
Originally Posted by GuitsBoy
You did check for any garbage stuck to teh magnetic tip of the cam sensor, no? Maybe the reluctor was ground incorrectly? Match it up to the stock cam to make sure it wasnt ground off target.
if you have a double roller timing chain, then that is your problem..
i had an SLP double roller and it was installed wrong. my tach didnt work at all and it was a bitch to fire up, wouldnt want to crank over... then i swapped out to an LS2 chain, and all the problems disappeard!
i had an SLP double roller and it was installed wrong. my tach didnt work at all and it was a bitch to fire up, wouldnt want to crank over... then i swapped out to an LS2 chain, and all the problems disappeard!