Alienlefty

I have an LS2 in my 64 Corvette with a Speed Demon and MSD 6LS-2 setup. I have been having all kinds of running on and erratic running problems. The car still has less than 400 miles since completion, and I went to start it yesterday, and it ran for a few seconds, spattered badly as if running on only 2 cylinders, then quit. I finally decided to pull a couple of spark plugs to confirm that I was getting a spark, and there is no spark. So I am suspicious that the MSD module has failed. Can anyone help me diagnose for sure?

Thanks.

Alienlefty

I read online that other people have had similar problems, and that when they connected the laptop, they got a 'Cam Sn Failure' message. So I set it up this morning and cranked it over, sure enough, I got the same message. But I have also read that replacing the cam sensor does not fix the problem. If I was in the States, I would just order a new cam sensor and try it. But I am in the UK. There are no dealers that I can find that will stock this item, so I have to import it. I have emailed MSD for help. but I don't know how long it will be before I get a response. Any help would be appreciated.

Thanks again.

Pop N Wood

iTrader: (1)

First off are you driving that vette around England? Must be pretty cool, you have to get some pretty serious looks in that.

Second you are right in that you can completely unplug the cam sensor and the car should start up correctly 50% of the time. So if individual cylinders are out when it does start then you probably have other issues as well. You can do a rough check of the cam sensor using a multimeter. A better tool would be an O scope. Google it, someone has it on youtube or written up on a car site.

Double check you have good power to the box and to the coil packs when running. Grounds are always important. You can use a 9V battery in place of the 5V MSD trigger signal to fire individual coil packs if needed

Any chance your carb is just running pig rich and fouling plugs?

Alienlefty

Well if I can ever get it to run, yes I drive it in England. The car has been troublesome for a while, hence the very low milage (only just over 300 since completion). I thought it was flooding at first, but looking at the plugs and holding them against the cylinder head whilst turning the engine over confirms there is no spark. I took the cam sensor out this morning and had a look. Another post suggested jiggling it around and even leaving it loose to see if a slight repositioning might help. But so far - nothing!

Based on what you are saying, I should at least get the engine to run with the sensor unplugged? I confess I find it very strange that an OEM sensor would go down so easily. GM LS motors just don't have that reputation. So I am suspicious of the MSD box. I have checked grounds etc. All looks good. The car is all new, so this is very frustrating.

I do have a multi meter (somewhere) . If I can find it, how do I test the sensor?

Pop N Wood

iTrader: (1)

You can definitely unplug the cam sensor and have the car run. The ignition box uses the crank sensor to tell it when to fire. The cam sensor just tells it which cycle of the cam to fire on, so without it the box randomly comes up in sync or 180° out. I had a bad can sensor connection for awhile and the car was just hard to start. it would occasionally backfire out the carb when starting. But just turn the key again and if it came up in sync then it started and ran fine.

I Googled "test cam sensor" and the first link I got was a youtube video from some guy in the UK no less showing how to test the sensor.

I really think you have a bigger issue. Like bad voltage to the box or poor grounds. Quite a few guys have done things like power the box from what use to be the coil wire. They then end up with the box either not powered during cranking or drawing juice through the ballast resistor when running. If I were you I would spend some time tracing voltages throughout the harness. Once I convinced myself I was getting a full 12V everywhere it needed to be I would then contact MSD and have them walk you through a diagnostic. Quite a few guys have had good luck with MSD customer service. Sometime just calling them will get them to ship you a new box.

You could also have bad coil packs or coil pack wiring.

Alienlefty

Spoke to MSD Tech Help today. They said to test the crank sensor. Of course, it is almost impossible to be sure you have a connection to that thing, but I couldn't get a reading. So I have to assume it is bad. Can't buy one in the UK, so for the time being, I am screwed!

Pop N Wood

iTrader: (1)

Yep, if your not getting an RPM reading on the lap top when cranking then that is your #1 issue to fix.

Did they have you try cranking it with the plugs removed? Quite a number of guys have reported problems with the crank signal and the MSD box unless they got it spinning over some minimum RPM.

Alienlefty

They didn't suggest that. I will try and find a sensor here in the UK, but I am running out of time as I will be emigrating in 4 weeks. I have the car up for sale, but who will buy a non runner?

Pop N Wood

iTrader: (1)

I would buy that car as it sits. You just won't get the dollars you should if it runs. Getting it driving and it will blow someones's mind. I have the same motor in my Zed and they are impressive in such a light car.

Is there a good shop anywhere near by? I'm definitely a fix it yourself kinda guy but if I were in your position there would be no shame in calling in a professional.

I have an extra cam sensor I could have sent you. But unfortunately I don't have an extra crank sensor. If you really get stuck PM me and I can pick one up and priority mail it to you. My guess is you can get it quicker ordering it from some non GM source.

Alienlefty

I have found one at Pace Performance for $28.95. I am waiting for them to get back to me. A lot of the online companies don't want to ship overseas, and if they do, they charge a fortune for it. If you were to send me one, I would be happy to reimburse you by check or Paypal. Whatever suited you.

I don't think finding a shop is going to work, because they will have the same problem getting hold of a sensor quickly. It takes 5 minutes to change the sensor, so getting one to try would be the quickest and easiest way to prove out the problem.

In about a month, I am moving back to Florida. I do have enough space in the container for the car, but the right hand drive issue is the reason I prefer to sell it on before I leave.

Pop N Wood

iTrader: (1)

That is a really good price. GM direct wants $50, plus they usually kill you on shipping. Autozone has one in stock in a local store for $47 + tax

http://www.autozone.com/autozone/par.../N-jmmnqZ9gslr

You might try Scoggin Dickey. They are a sponser on here known for their good service and I know they ship overseas.

Let me know if you need my help. If nothing else you can have Pace ship it to my address and I will turn around and mail it to you. Probably should go to PM for that.

Alienlefty

Well, Tom Falconer at Claremont Corvette got me a new crank sensor at great expense. But he ordered an LS1 Sensor. I said it wouldn't work, and it didn't. The Software came up with a 'Crank Sensor Failure' message, so I put the original one back in and called MSD again. They ran me through another bunch of tests, which I wish they had done in the first place! Proving now that the box is at fault. They offered to swap out my unit but I had to find the original receipt and destroy the box I had, and send them photo evidence that I had done so. I don't have the receipt, so I ordered one from Summit. I won't get that until Monday at the earliest. As luck would have it, my MOT and insurance both run out this weekend. This couldn't have gone worse if I had planned it. This will be my last Corvette, and my last MSD. Never again!

ZONES89RS

iTrader: (25)

Don't give up so fast. Wait till it is together an running ultra hard and you get all the looks and comments of having that thing beating the streets.

Pop N Wood

iTrader: (1)

Well that sucks. I had my doubts about the crank sensor being the fix. Wish that had been it.

Like Zones said that car will unquestionably be worth the trouble once you get it running. That motor will make the car sing. Too bad it might happen too late for you to enjoy it.

The MSD box is really the only game in town for a carb'd LS motor. FAST makes an ignition box but it is a good bit more money. The only other option I can think of would be keeping the stock ECU or a Megasquirt box just to run the spark. That would sort of be the worst of both worlds, might as well fuel inject it at that point.

Well hopefully your new box will give you a plug and go experience like 99% of us on here have had with our boxes. These ignitions kick the **** out of an old distributor set up. When they work I guess.

bad67ls

iTrader: (2)

i had one fail on me as well. car was togather for about 3 weeks. took it to a rental at atco (cost me a good chunk of change in gas and tolls, the day off work and the rental fee) the 2step wasnt working at all, and after the third pass the box stared firing random cylinders and went up in smoke...literally pouring smoke out of the holes where the timing pills plug in.

msd actually had my local speed shop (sk speed in lindenhurst) hand me a new one within a few days and its been trouble free since (knock on wood)