1967 RS Duramax Camaro

IdahoRob

New member
Jun 5, 2007
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Curious, but could the electrical systems of older cars just not be up to the task of carrying enough consistent voltage to adequately power these modern computer-controlled engines?

Is there a way to test the crank/cam sensors out of the engine to see if they are still good? For that matter, what would cause them to become "bad" from sitting in the first place?

What I think the difference is Tom is that stock Dmax equipped trucks have the batteries right near the ecm, starter, and fuse box. The cables also have a separate lead to the fuse box in a stock application. So they are getting the direct voltage needed to run everything.

When running a single battery in the rear and long cables to the starter, then running the power leads for ignition and ecm off the starter (because it's easy) and the ecm cannot power everything up when cranking.

These ecms are very finicky when it comes to voltage and grounds.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
15,610
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Mid Michigan
What I think the difference is Tom is that stock Dmax equipped trucks have the batteries right near the ecm, starter, and fuse box. The cables also have a separate lead to the fuse box in a stock application. So they are getting the direct voltage needed to run everything.

When running a single battery in the rear and long cables to the starter, then running the power leads for ignition and ecm off the starter (because it's easy) and the ecm cannot power everything up when cranking.

These ecms are very finicky when it comes to voltage and grounds.

That makes perfect sense, Rob. I didnt even think about the wakeup voltage. The voltage drop from the rear would exaberate that problem. Thanks.
 

maxxin-n-style

New member
Jul 8, 2013
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abq, new mexico
Its almost 4 in the morning and ive been reading every page on this build lol.. you did an amazing job and didnt halfass on anything on this whole build!! This whole starting issue you will get passed soon and finally get to drive this beast!! Cant wait to see it in all the diesel magazines and at the strip!! You, my friend, got some amazing skills!!
 

Yellow Jacket

WannaBe Sled Puller
Feb 11, 2009
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Waterloo, IA
If the sensors are switched with each other it won't start either, I have had this problem before... the cam sensor connector should be straight up and down, vertical... and the crank sensor should be flat parallel.

I didn't read all 19 pages, so this may have been stated
 
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dslhtrdr

Always learning
Nov 22, 2012
262
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Sebastopol, Ca
Hell yea! :thumb:

:woott:

Awesome bud, nice to see her up and running! We've got a triple kit that will bolt to that LLY accy bracket ;)

Could you imagine how it would just rip with triples??

Dayuuuumn :)

Don't tempt me :rofl: I think the Camaro will be fast enough with a single. I'll get it road worthy and see how I like it...

What did you end up finding wrong with it to keep it from starting?


Roll Tide!

I had 2 wires hooked up wrong. When we were getting the majority of the wiring hooked up in July, we got into a hurry and left 2 wires unlabeled. 1 was the tach signal wire and the other happened to be the ground wire for the fuse block and relays we built for the ECM. At the time I was pretty certain which was which, and I was wrong. The ECM wasn't telling the injectors to fire, among other things, because the circuit was incomplete and wouldn't allow it to start.

Bow chicka bow wow!!!! :woott: :thumb:

:thumb:
 

dslhtrdr

Always learning
Nov 22, 2012
262
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0
Sebastopol, Ca
Thanks Tom. I had a little time to work on it today. Fully charged the batteries and it fires up much faster than in the video.

Going to get it moveable sometime this week. Have to finish filling up the tranny with atf and bleed the brakes.

Next on the build list is to fabricate all the intercooler and intake piping. To all you guys that have built intercooler piping, what have you done to mount the MAP sensor? I bought the weld on MAF port from PPE for the intake, but haven't seen much of anything about the MAP sensor on LBZ's. I would prefer to not buy a intercooler pipe meant for a truck that I would have to cut up to fit my application.

I don't think it would take much to make my own, just need a little advice from what you have done.
 

malibu795

misspeelleerr
Apr 28, 2007
8,231
548
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in the buckeye state
Thanks Tom. I had a little time to work on it today. Fully charged the batteries and it fires up much faster than in the video.

Going to get it moveable sometime this week. Have to finish filling up the tranny with atf and bleed the brakes.

Next on the build list is to fabricate all the intercooler and intake piping. To all you guys that have built intercooler piping, what have you done to mount the MAP sensor? I bought the weld on MAF port from PPE for the intake, but haven't seen much of anything about the MAP sensor on LBZ's. I would prefer to not buy a intercooler pipe meant for a truck that I would have to cut up to fit my application.

I don't think it would take much to make my own, just need a little advice from what you have done.

i have made my own on my repower.. IIRC several shops danville, merchant, ppe sell both style of MAF adapter that can be welded on to a 4, 5, 6" pipes
 

dslhtrdr

Always learning
Nov 22, 2012
262
0
0
Sebastopol, Ca
i have made my own on my repower.. IIRC several shops danville, merchant, ppe sell both style of MAF adapter that can be welded on to a 4, 5, 6" pipes

Right, I have the MAF adapter from ppe. I'm looking for an adapter/bung that I can weld onto piping for the MAP sensor and have been unable to find such part.
 

malibu795

misspeelleerr
Apr 28, 2007
8,231
548
113
42
in the buckeye state
Right, I have the MAF adapter from ppe. I'm looking for an adapter/bung that I can weld onto piping for the MAP sensor and have been unable to find such part.

iirc it needs a 5/16" dia hole. i used a 2.5" aluminum elbow. had a friend drill and weld some round stock that was drilled and tapped for 1/4-20 to secure it, along with a flange to bolt it to the intake..mine isnt show quality but it works very well. i think the walls on the elbow is 1/8 to 3/16" thick
1391565_10201622788425092_1433482649_n.jpg

this is what i used elbow wise
http://www.jegs.com/i/Turbonetics/880/20544/10002/-1