Portland Oregon No-Start Mystery

[GilTheArtist]

Hey guys, first time poster. Hoping to find someone near my area to come out and help me solve this. Ill cut right to the chase.

This is an 87 mk3 7mgte automatic with about 230000 miles.
I have a no-start condition with codes 12 and 51.
Began 2 months ago. When running, i would shift into park and the rpm would surge up to 1500. Then go back to normal (800) in neutral and drive. It also needed me to hit the gas once or twice to crank over.
After a few weeks of this, one morning before work, it struggled once. Then cranked over the 2nd attempt. But then immediately died and has not fired again ever since.
The battery is still charged and is able to turn on electronics.
Fuel tank is half full.
With +b and fp jumped, fuel pump is audibly functional.
Starter cranks and spins pulleys.

Now heres what ive done so far:
Extracted code 12 (rpm crank angle signal)
Cps was replaced in 2015 with a new one from AutoZone.

Extracted code 51 (neutral start switch, ac signal on, or tps signal)
Ac is definitely off. In the process of replacing tps with new one from AutoZone.
Have not been able to check neutral start switch.

Ignition coils all test to spec. However no spark is visible when i pull the ignition wire out just a bit on all 6.

Replaced coil harness with brand new harness.

Replaced coil ground with new ground wire.

Replaced ignitor twice for good measure.

Replaced fuel pump relay

Replaced main relay

No burnt fuses anywhere

Rewired cps all the way back to ecu with brand new harness

I have a used (but supposedly functional) cps ready to install, just needs new o-ring, but the cps on the car right now is testing at 180ohms resistance between all pins, which a mechanic peer has told me is close enough to the stock specs of 210ohms to still theoretically be functional. Its also spotless inside of the dust cover. Still practically new.

I am about to open the timing cover to check for a broken timing belt. I have the kit ready to install, but i dont know if thats a good idea since the car is not running and i wont be able to set the timing properly. Could this be the cause of the no-start?

I am close to my wits end, and would appreciate any and all help, most especially someone local willing to visit my car by Mt Tabor in Portland.

Thanks for reading guys
-gil.
Giltheartist@gmail.com
8185642606

 

[plaaya69]

I would not throw more parts until you test your TPS sensor per TSRM. To me with that idle surge to 1500 to 800 it sounds like a bad or out of adjustment TPS sensor. Have you adjusted that sensor or had it off of the car since your problem?

When you tested for spark did you have the spark plug wire end grounded to the cylinder head?

Neutral safety start switch will not engage the starter if it is bad or out of gear but if it cranks over every time, then I would not worry about that part.

You can check to see if the camshaft lobe is moving with the oil cap off while cranking over the motor so you don't have to take off the timing cover.

 

[GilTheArtist]

OP UPDATE:

Ive just replaced and callibrated to spec the new tps sensor i mentioned.
Code 51 officially gone so i can only assume the neutral start switch was and still is completely fine.

Ive also gone ahead and opened the upper timing cover to inspect the belt.
It is definitely worn and cracked but not broken and definitely still tensioned tight enough to be moving the cam and crank pulleys in sync. I did find one 'belt tooth' that had come loose and was nestled in some grease in a corner of the timing housing.
Im still planning on replacing this since ive already got the parts, but im pretty sure this is not the cause of my no-start.

 

[plaaya69]

Check to see if all 3 timing marks (both camshaft gears and harmonic pulley at the bottom) are all lined up.

 

[GilTheArtist]

OP UPDATE:
the 2 cam pulleys are aligned but i havnt taken the bottom cover off, ill check that soon.

Ive removed the circuit opening relay and found that there is no continuity between B and FC. And apparently there should be. Capacitor looks fine and other terminals test ok. Gonna try to replace that and post results.

Used cps i bought from a supra owner named nick with a 360 area code is junk, and hes dodging my messages now after ripping me off for $100.
So ill have to buy a rebuilt one from rockauto if i decide to replace that.

 

[plaaya69]

Yes, its a good idea to get a new one from Rock Auto for $170 (there is also a 5% off promo code on here that expires sometime in July). On the bottom mark you do not need to take off any covers. It is marked on the outer lower timing cover and you will see a notch in the harmonic pulley to line it up with.

If you bought through paypal you may still have time to resolve it under disputes.

 

[GilTheArtist]

OP UPDATE:
Ok, big development.
I got my hands on a breaker bar, and after taking the fan blades off the fan clutch, attempted to turn the crank to see if the markings align, and the cam pulleys werent moving at all!
The timing belt wasnt flinching one bit. So i have to believe that its ripped under the oil pump pulley or stuck on something because its still tight and wont come out when i tug on it.

I need someone to turn the key to crack the nut off, and people are scarce at the moment. More updates later.

In a related issue, i cant get the fan clutch to stop turning when i try to unbolt it. Im going ahead and replacing my water pump since i have a new one that came with the timing belt.
Anyone have any advice? Theres no hex for a fan clutch holding tool like some american cars ive seen.
I tried to unbolt while holding crank pulley but it spins independant of the belt thats wrapped around it.

 

[GilTheArtist]

In case anyone else searches for this,
I got the fan clutch off by holding it by one of the nuts with an open ended wrench and after cracking off 3 of them, retightening 1 to crack off the last one.
The retightened one will give enough leverage without having to be too tight to loosen up again without holding the clutch at all.

 

[f00g00]

I push down on the belt to create more tension on the pulley to remove the bolts.

 

[GilTheArtist]

OP UPDATE:
The power steering pump was stuck really good. I removed the whole adjusting bracket and finally budged it by putting enough downward pressure on the belt i was trying to loosen. Got the belt off.
Finally got the harmonic balancer off, used the standard puller and managed to do it with just 2 bolts in it, only seeing afterwards that i actually could have accomodated all 4.
This is where i realized the AC compressor had to go. The bottom corner of the bracket was effectively blocking the bottom timing cover from being removed. Had to remove the r12 lines first which were empty, one bolt from the corner, then the 2 top mounting bolts on the side, then the bottom rear one by shoving my arm past the intake manifold to used an alternating grip on a closed end wrench to blindly squeek it out, then the bottom front one i reached from underneath the car just in front of the wheel with an extension, then finally 2 more bracket bolts going into the block.
At this point it was nighttime but i was able to see that the belt was not cut in 2, but was still stuck somehow or so ground up that the crank teeth could no longer push it. I found what appeared to be an oily rubber residue in an outward spray pattern with the consistency of powdered graphite.

Next im going to install the new belt to turn the cams to 12:00 together, then remove it to get the crank to 12:00. Then reinstall the belt and close that all up.

That should be the equivalent of TDC am i right? I know one revolution of the cam is only a half revolution of the crank, and that it takes 2 crank revolutions to complete a combustion cycle.
So are both instances of the crank reaching 12:00 suitable places to sync up the cams? Or is only one of the rotations (intake and exhaust) meant to be aligned with the cams at 12:00.
Am i overcomplicating something simple?

 

[GilTheArtist]

Who knows if the 'rope method' for retorqing the crank bolt could damage the valves? Is this only an acceptable procedure when the cams and valves are removed?

 

[plaaya69]

When retorting the crank DO NOT do that rope trick. That should only be used to help keep the valves in place when removing the valve retainers and also it could get tangled up in a knot as well. Just take off the front lower inspection plate on the transmission and use something to hold the flywheel while you torque the bolt down.

 

[GilTheArtist]

OP UPDATE:
New timing belt and tensioner installed

I did not use the rope method, both out of fear of damaging the valves and because the only rope i had on hand was too thick.
I tried to fashion a 5 foot 2x4 into a crank holding tool but after 100lbs of torque the 2 holding bolts began to give way, and the crank bolt felt like it might strip if i pushed any harder.

New alt and ps belt installed, the pump was still pretty stuck and i wasnt able to tighten as much as i wouldve liked, but didnt leave it floppy.

New spark plugs, just double platinum 7088 gapped at 0.031 per the tsrm.

New waterpump and fan clutch installed.

New fuel circuit solenoid installed.

AAAAAND it starts. Ran slightly bumpy at first as the original cps did its job, it WAS good like i had thought all along.
Some white/super light blue smoke coming out of the exhaust for a few minutes, lightened up after a while.

But troublecodes are all cleared and this thread is closed. Thanks to everyone who participated, hope my plight helps someone else in the future.