GEMS 4.6 with Crower cam issue

lunchbox

Well-known member
Apr 20, 2004
2,043
108
49
St Louis, MO
Hey

I finally got my knock sorted out. Now I am having issues with the cam and crank sensors. I'm throwing code 340 and all kinds of associated misfire and o2 codes. I've swapped several sensors and no change. I've done two sets of new plugs and wires as well. I've traced the wires pretty far into the loom and cleaned up one frayed wire from the crank sensor. Any other suggestions? Also...the ECU is showing 17v at testbook and the alt is steady at 13.8

Thanks

Chad
 

robertf

Well-known member
Jan 22, 2006
4,609
242
-
Is it the original Ecu? I've read about the early gems showing the wrong voltage as a design flaw.

Did this engine ever run right?
 

lunchbox

Well-known member
Apr 20, 2004
2,043
108
49
St Louis, MO
It is the original ECU. The oldt engine had over 200k. It ran fine but was real tired. I decided to build a new one. The new one knocked bad on first start. It did not throw a single code though. The knock was a shit cam from Crower. Replaced the cam. No knock, but runs like shit and throws codes.
 

robertf

Well-known member
Jan 22, 2006
4,609
242
-
Any idea what was wrong with the first cam?


I'd check the compression. I suspect the first cam was somehow advanced a timing gear tooth or two and maybe bent some valves
 

lunchbox

Well-known member
Apr 20, 2004
2,043
108
49
St Louis, MO
Crower sent a bad cam the first time. Sending it back to get more info. It had at least one bad lobe. The engine was torn back down for the new cam. New lifters. Compression is good.
 

lunchbox

Well-known member
Apr 20, 2004
2,043
108
49
St Louis, MO
We were just discussing that. That will be checked next.

Does anyone know if you still need a spacer on the cam sensor with Crower cams? I know the older ones needed machine work and a spacer.
 

robertf

Well-known member
Jan 22, 2006
4,609
242
-
If you bought the 532xx cam from crower no spacer needed, pretend it's a factory cam. If you bought some modified 502xx cam like what d&d sells, God help you
 

lunchbox

Well-known member
Apr 20, 2004
2,043
108
49
St Louis, MO
The first cam was bought from summit. The second cam was one the shop already had for another project. It was supposed to be the same part number that should have been in the first box. I'll text the shop and see what part number it was.
 

lunchbox

Well-known member
Apr 20, 2004
2,043
108
49
St Louis, MO
Ha. No way in hell I am pulling the tranny. I'll pull the engine. Good news is that it goes in and out real easy with all of the new hardware and fresh gaskets. I just hope that one little tooth is enough to causes all of the shit this truck is giving me now. Crower sending me a junk ass cam was bad enough. But this is really pissing me off.