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Underdrive pulley fell off, now no spark?

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radeagle

Probationary Member
17
0
Aug 23, 2013
Frankfort, Indiana
Ok, so I'm one week old in the dsm world and Im already having problems. My underdrive pulley came off while cruising down the interstate a 75mph. My car just died completely and now has no spark at all. I've looked at a lot of post but I can't really find anything for built 420a engines so please help if you can.

I have a new harmonic balancer on the way with new belts a d they will be going on tomorrow, but that's not going to give me spark....
 
Wonder if you smacked up the crank angle sensor wires when the pulley fell off causing this failure in getting spark - be my only guess since that unit is what determines when plugs do fire.

Be my first area to look at.

Odd though - how did a pulley fall off when it's pressed on front of the crankshaft?
 
It didn't fall completely off but idk how. The power steering and alt belt came off cause it was so loose and the bolt was completely backed out. The pulley just fell into my hand when I grabbed it. It is aluminum and is worn out on the inside. The car just sounded like I had turned the key off...no sputter or noise.
 
So I got my new (stock) harmonic balancer and belts and went to install them. My first problem is that the aluminum underdrive pulley left behind some aluminum on the shaft. My second problem is the harmonic balancer won't fit on unless I pull the engine...or at least thats what it seems to me. Any ideas what to do?
 
To get the metal off the shaft use some emery cloth. You will need a pulley install tool which most likely wont come with the correct bolts so you'll have to buy those. Check your mechanical timing, crank position sensor (it's on the back of the block), and lastly check the battery. You said the alt came off so it's possible you drained the battery going down the road.
 
I looked everywhere and can't find any damage it might have done. The battery was still charged enough to crank the engine over at a decent speed for me to check for spark so the belt couldn't have been off long.
 
I looked everywhere and can't find any damage it might have done. The battery was still charged enough to crank the engine over at a decent speed for me to check for spark so the belt couldn't have been off long.

Have you checked the voltage at the coil? and ohm the coil to confirm it's good.
 
No check engine light? Really odd the pulley just came loose I'm sure you have something wrong with your set up. I would check all the bolts on that side of the engine. You might need to rest your ecu too it might be in safe mode to not let it start since your belts came off.
 
How do I reset it? I changed the crank position sensor and still no spark.

Like I said before, the pulley wasn't completely off but just sitting on the edge of the shaft when I got to it. The bolt was also there and looks to have some stripped threads...
 
How do I reset it? I changed the crank position sensor and still no spark.

Like I said before, the pulley wasn't completely off but just sitting on the edge of the shaft when I got to it. The bolt was also there and looks to have some stripped threads...

Unhook the battery (both sides) for 10 mins or so. This will clear codes and put the car back into its learn mode for fuel trims and idle control. I wouldn't think that resetting the ecu would give you spark back. I would check voltage to the coil and then ohm the coils to ensure they are good. To check the voltage turn the car on and test the middle wire in the ignition coil plug. If there is good voltage turn the car off and check the resistance of the 2 coils. Here's a vid explaining how.
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Just got a socket and rolled my engine around and set the cam timing marks together and looked at the crank timing mark and its pointing towards the lower tensioner bolt. I know this is off, but what I don't know is why. I've said before that I don't know anything really about these engines, so my question now is, are my valves and piston ruined? I had a 3000 gt once and the timing jumped 2 teeth and the valves all bent....is this going to be the same way?
 
You need to line the crank mark up first and then look at the cams to see how far its off. Most likely the force of the underdrive pulley coming off knocked your timing off a few teeth. Check the timing the way I said and let us know how far its off. Most likely you bent a few valves if its more than 1 tooth off, it is a interference motor. This would also explain your no spark issue, also if the motor still rotates freely you may have gotten lucky.
 
Well the pulley falling off wouldn't change the crank position because the belt rides behind the plastic cover on the crank sprocket. I would get your timing set right and make sure your tensioner is still good. After that rotate be hand and see if it spins with out binding. If that checks out do a leak down or compression test. If you don't know how to test the ohms I would go buy a coil pack from auto zone. If it doesn't fix the spark issue then take it back for your money. Also you need to check for voltage on the asd relay that will cause no spark too. The asd relay is on the firewall above the break resivor it's a black little square relay. Do you hear your fuel pump turn on when you put the key to accel? I would also assume that if your pulley got loose then the crank bolt threads need to be repaired but I'm only assuming that with your issue.

Dsmkauai has a good point so be careful with what you do.
 
Ok, I did that and they are 4 teeth from lining up in the center. The Motor turnes over freely by hand and makes 0 noise....is that good or is that just bexause I already bent the valves turning it over with the key to chexk for spark?
 
Ya 4 teeth off is a definite bad thing and I don't see any way your valves arnt bent bro! Sorry :( only thing you can do now it pull the head and see the extent of the damage. I mean you could always try to redo the timing and see what happens, and do a conpression test, but honestly seems like a waste of time to me.
 
Man...this always happens to me. 3 motors in a 3000gt, loss of 2k. 2 engines and a rebuild in a 87 iroc z loss of 4k, and now 5 days after I buy this car and its junk. My wife is gonna be so happy. :p
 
Pull the spark plugs out and shine a flash light down and see if there is metal flakes or chucks of metal on top of the pistons. But it doesn't sound good man. I just had my valves bent 3 weeks ago on a built motor with 7k on it so your not the only one.
 
I rolled the engine around by hand and there was no noise, so would it be safe to do a compression test? Also if my valves are bent, should I replace them with the same stainless steel ones that are in it? And are the timing belt kits on ebay ok for these cars turboed...or do I need the really expensive ones?
 
I rolled the engine around by hand and there was no noise, so would it be safe to do a compression test? Also if my valves are bent, should I replace them with the same stainless steel ones that are in it? And are the timing belt kits on ebay ok for these cars turboed...or do I need the really expensive ones?
Turning the engine by hand isn't necessarily a great way to test if valves are bent. Your pistons do sometimes bend them out of the way when they get punted at high speed.

Don't get an ebay timing belt kit unless you want to do it again. As far as the valves go, this guy's stuff is the real deal at a great price:

4g63 Stainless Valves Stock Size H P Eclipse Eagle DOHC 2 0L EVO DSM | eBay

OEM is never a bad choice for the timing components, partsdinosaur.com has some great priced stuff if you don't want to spend 400$ on an all OEM kit, though. Good luck, and after this debacle you'll make sure to take your manual out to the car with you to tighten everything to specifications, right? ;)

Shit just realized you were N/T disregard links and info.
 
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The problem is checking compression with the timing marks off won't do anything for you bro. You could try and reset timing and then do a compression test, but honestly if it jumped that many teeth I don't see anyway the valves arnt bent.
 
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