Up-pipe blew off, now won't start

[2QUIK6]

Today I took thje GN for a spin, was accelerating with about 15lbs of boost, not full throttle and it popped very loud and died...coasted down a block and pulled into parking lot and stopped.
Up-pipe was blown off at the throttle body. I use huge T-Clamps so I'm not sure why it blew off, my boost is set at around 23-24# with methanol inj and regularly take it to that with no issues.
I noticed the vac line to the EGR solenoid was popped off too.

Reinstalled the up-pipe, plugged back up the EGR and it will just crank and crank and not even try to fire.

I've checked all the fuses, all are good. I checked the coil and ign module with a Caspers coil/ign module tester, they seem fine...

I suspect that something cut spark to the engine which caused the up-pipe to blow off, I just don't think I had enough boost to do that given the large T-clamps. I have a spare crank sensor but haven't tried that yet... Any other ideas to look for?

 

[TurboBuRick]

Sounds like the tab broke on the cam sensor.

 

[2QUIK6]

Sounds like the tab broke on the cam sensor.

Tab? From what I remember its like a cup with a "window" cut out of it rather than a tab sticking up to pass the hall-effect sensor right? I have a spare cam sensor also that I will try if the crank sensor doesn't work. Also from what I understand, if it were something that caused the spark to be cut that caused the up-pipe to blow off in the first place, the cam sensor is only used during starting/cranking, once motor is running only the crank sensor is used.

 

[MeanBuicks]

Correct. The cam sensor can be unplugged while the engine is running and it won't kill it. Crank sensor failure will kill the engine immediately though.

http://www.vortexbuicks-etc.com/no_start_tree.htm

 

[TurboBuRick]

The tab keeps the wheel keyed to the shaft. When the tab breaks the wheel turns and throws off injector timing. That's what blew off the pipe. Not loosing ignition. The cam sensor is used for sequential fuel injection. It's not just for starting.

2 screws and the cap is off. Grab the wheel and see if it turns. I bet it does.

 

[TexasT]

So, it is making spark at a plug?
Timing set updated? Could have jumped time.
Compression check? Any funny noises while cranking? Busted a hg?
Fuel pressure at rail?
Try the new crank sensor. Never know?
Ses, any codes?

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[2QUIK6]

The tab keeps the wheel keyed to the shaft. When the tab breaks the wheel turns and throws off injector timing. That's what blew off the pipe. Not loosing ignition. The cam sensor is used for sequential fuel injection. It's not just for starting.

2 screws and the cap is off. Grab the wheel and see if it turns. I bet it does.

Ah, I see, I'll have to check it out one evening this week, thanks for the help, I'll post back what I find. It was acting just a little weird trying to start at the parts store just before, every once in a while the anti-theft seq on the Extender chip takes a few tries, but this time it was about 4 tries to start, but usually when the seq is not done, there is no fuel pressure, that time there was, but was still hard to start.

 

[2QUIK6]

So, it is making spark at a plug?
Timing set updated? Could have jumped time.
Compression check? Any funny noises while cranking? Busted a hg?
Fuel pressure at rail?
Try the new crank sensor. Never know?
Ses, any codes?

Posted from the TurboBuick.Com mobile app

Yep, timing set is a double roller, been on for years and about 15k miles...no tensioner btw.
Haven't done a compression check at this point, no funny noises, no leaks anywhere, I think the hg are ok.
Fuel pressure looks fine, I have an in cockpit Autometer els.

I'll pop the cap off the cam sensor as Rick mentioned above since its easy enough to get to, then move on to the crank sensor if nothing there one evening this week after work..... I was already working on my '95TA trying to get it running after it sitting a few months and had ran up to get some more parts when this happened...so I'm a little car worked out now Thanks for the tips Rick and Rich!

 

[Chuck Leeper]

While you have the sensor cap off, crank the engine and see if the sensor is moving.

 

[2QUIK6]

Well curiosity got the best of me, had to jack it up tonight and take a quick look at the crank sensor, didn't have time to fix it, but it appears the crank sensor is the problem since only 1 fin is left on it!

 

[Heisenberg]

Well curiosity got the best of me, had to jack it up tonight and take a quick look at the crank sensor, didn't have time to fix it, but it appears the crank sensor is the problem since only 1 fin is left on it!

Maybe it is your fuel line clip / clamp/ whatever?

Hate to give a broken crank sensor a "LIKE" - but I like that you seem to have found what should be an easy fix.

 

[TexasT]

Glad you found it.

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[phil_jordan]

I wonder how it got that way. Glad you found it.

 

[2QUIK6]

Not sure how it got inthe way of the rotating reluctor, but i have heard they have a tendancy to vibrate loose, its been a very long time since it was off... Probably when i installed the V4 IC and thats been about 12 years... It didnt feel loose but after it got the crap knocked out of it, it may be lodged in now. Will have to jack it up and rotate the crank around and check it closer before removing it.

 

[Grumpy]

Not sure how it got inthe way of the rotating reluctor, but i have heard they have a tendancy to vibrate loose, its been a very long time since it was off...

hmmm crank sensor slot passes threw the reluctor wheel .. I don't understand what your saying ????

 

[captndave737]

The reluctor wheel has 3 tabs on it that pass through the slot in the crank sensor, it's a hall effect device and the magnetic field changes, depending on whether steel or air is in the gap. This generates the signal to fire the spark plugs. We have 3 coils so three tabs on the reluctor.
If the crank sensor got loose it could hit the tabs on the reluctor causing them to break although it seems to me that the sensor itself is more likely to be destroyed by the reluctor.

 

[2QUIK6]

Notice in pic the sensor only has 1 of the 3 tabs that stick out that the rotating tabs/reluctors pass between. Somehow the sensor became misaligned and the rotating part knocked them off breaking the sensor in half.

 

[captndave737]

Man that sucks. I know you can buy a new sensor. How's the bracket, cant tell in the picture? Im sure the mounting bracket and reluctor ring aren't easy to come by.

 

[oldsracer]

I bought a new sensor from an aftermarket company we use (repair shop) and it worked great and came with a bracket.

 

[2QUIK6]

I've got a spare Delco sensor that is on the bracket, its the newer style sensor, also have a bracket for the old style, some I'm covered, may be Thursday before I can mess with it.