ProfEd

iTrader: (1)

Hey guys,
My old heads were leaking like crazy from the rear freeze plugs, so I went ahead and got some new PRC heads from TSP, along with a Torquer v2 cam, oil pump, timing set, LS7 lifters, pushrods, Comp trunnion bearings, etc. The install went smooth and the engine runs reasonably well (obviously need a tune). My other engine mods are Pacesetter LT's, ORY, LS6 mani, lid.

I do not have a tach/rpm signal and the SES light is now on.

It is difficult to start, and may need to be turned over 3 or 4 times before it starts. Once started it idles poorly, but will not actually die. It falls on its face and almost dies if I rev it up slightly (like 1500-1800) and then let off abruptly. I have not taken it over what I believe to be 3000 or so while driving, and I am just babying it around for the next week or two until I can get everything ironed out and get scheduled with Jeremy Formato to tune it again. I have only put about 30 miles on it so far, but I have to use it to get to work until I get a chance to finish the engine swap in my other car. For the time being it actually runs reasonably smooth once up to speed, though I know the air/fuel is definitely out of whack. Having an m6 definitely helps, I'm sure.

I am looking into this being a crank sensor or cam sensor issue. I checked the plugs and wires on both and they "seem" to be in place without any breaks. To check the cam sensor and be 100% sure I will obviously need to remove the manifold again.

In the meantime, does anyone have any advice or ideas as to what the issue could be? Based on the issues mentioned, is it more likely to be a cam or crank sensor (or something else)?

I greatly appreciate your help!

Thanks,
Ed

sreve

iTrader: (3)

Sounds like the cam sensor may not be plugged in.
You need to check the codes although an SES light and a crappy
idle are common to a new cam untuned.
the mechanical problems do need fixed bafore you take it to be tuned
unless your planning to pay them to fix them.

ProfEd

iTrader: (1)

Thanks for the reply. I wedged my hand back behind the manifold and the cam sensor is definitely plugged in, but maybe the wires are not making a good connection or something. Are you leaning towards cam sensor and not a crank sensor? At least that will help me in my diagnosis.

Thanks,
Ed

sreve

iTrader: (3)

The hard starting and no tach had me thinking cam sensor.
Jumper terminals 4 & 5 on the data link and see if the tach works.

ProfEd

iTrader: (1)

Well, I finally had some time to swap in a new cam sensor. The symptoms are still the same (no tach, and may take multiple tries to start). I scanned it and it is still showing "Cam position sensor, low voltage", even after the new sensor. I checked all of the wiring and the plug and it seems to all be functioning properly.

I am wondering at this point if TSP sent me an LS2 cam by accident. I did not inspect it that closely when I put it in and I am wondering if there simply isn't a cam sensor trigger on the new cam.

The other possibility as I see it could be loose cam retaining plate bolts or loose cam gear bolts. I seriously doubt it on either of these; I installed with loctite and torqued to spec. I have read some information saying that loose bolts on either of these could cause the cam to float and the cam position sensor misses the trigger on the back of the cam.

I have been driving the car and have put about 200 miles on it now. It actually runs reasonably well, considering that it is bank firing the injectors from this cam sensor issue. I am going to inspect for loose bolts and then call Texas Speed to see what my options are. Obviously, I am pretty frustrated, but there isn't much I can do.

If it turns out to be the wrong camshaft, I think I may swap to LS2 cam sensor and just keep this cam in it, because it would save me a little work and the potential shipping time.

If my suspicions are correct, and it turns out that I have an LS2 cam by accident, what all is needed to swap my 1999 LS1 wiring harness to work with it? LS2 cam gear, timing cover with new sensor, and extend the wiring harness? Is that all I would need?

Thanks again,
Ed

sreve

iTrader: (3)

Did you check the cmp connector for power and grd?
The PCM grds are on the back of the left head.
Jumper terminals 4 & 5 on the data link and see if the tach works
that will jump sensor grd to chassis grd.

hiltsy855

iTrader: (35)

Check the ground wires on back of the driver's side head. Pretty common to forget to reinstall them.

ProfEd

iTrader: (1)

I have visually inspected the wiring, but I have not tested it. All three ground wires are snug on the back of the driver's side head. I will definitely try what you suggested... When you say "data link" is that the OBDII port under the steering column? If so, are the terminals marked, or is there a schematic somewhere?

Thanks again!
-Ed

ProfEd

iTrader: (1)

I just tried to jump #4 and 5 together, but it did not have any affect. I am guessing it is either a voltage issue (I will check the wiring) or there is no reluctor on the new cam, hence the lack of Cam Position signal. Any other ideas that I could check? I already checked the other plug near where the EGR used to be...it is seated properly and the wiring seems fine. Still scratching my head on this one. I still intend on pulling the manifold again and removing the cam sensor and actually looking in the hole to see if the trigger wheel is on the cam...

Thanks,
Ed

ProfEd

iTrader: (1)

Problem solved!

I pulled the intake manifold again tonight and then pulled the Cam Position Sensor out of the hole. I used my cell phone camera to shoot some pics down the hole. There was a reluctor wheel there and it seemed to be properly centered in the hole, so that was not the issue.

I next tested the sensor wires and had a short to voltage. Despite the short I could not find a defect in the wiring; everywhere I looked appeared fine...obviously this is why testing it is crucial.

I went ahead and ran new wires for all three CMP wires and bypassed the silly connector that is on the 98/99 models. I used heatshrink on the connections and ran it all together very cleanly in a new loom. If you didn't know exactly what to look for you would assume it was all factory.

Thanks for the advice and hopefully this may help someone in the future if they have an issue after a heads/cam swap.

-Ed