91 300zx N/A shakes and died, hasn't started since

[speeddemon72]

Okay so late fall November of last year, my baby died on me. I was setting dead still at a light and the car just shook and died. Had never started since. I took it to the idiots at firestone and they said it was getting fuel and air, the ignition control module was replaced so it should receive spark too. Another mechanic ran a compression test and said the entire passenger side of the motor had no compression. Also that there was a timeing issue which apparently is a common problem with this car. I love coco (my cocaine white baby Z). And I just wanna drive her at least one more time. So any info on what I just please let me know. Rebuild maybe?

[speeddemon72]

Also the car would still crank just not start.

[nissanfreak12]

It is very possible the timing belt skipped a tooth on the passenger side. It could be that simple, but that also means it could have engine damage if this is the case. Unlikely if it was at idle. Only way to tell is to take the covers off and count the cogs of the timing belt. But from what you described and saying no compression in the passenger side, that points toward timing belt issue.

Just for the record, it is not a common problems with timing issues at all as long as you replace the belt at the suggested times 4yrs or 60k miles. Chances are the tensioner either failed, belt stretched, or belt was not installed to spec.

How old is the belt?

When was the last time it was replaced?

And last thought, I know it may have been a desperation move, but do not take your car to firstone, especially a z. No disrespect if anyone works at Firestone, but generally these are guys that just started in the industry, have minimal training, and honestly most just don't care. I only say this cause I worked at one when I was a teen just starting out. Yes there are some really good mechanics that work there, but few and far between.

[DCaff300ZX]

It is very possible the timing belt skipped a tooth on the passenger side. It could be that simple, but that also means it could have engine damage if this is the case. Unlikely if it was at idle. Only way to tell is to take the covers off and count the cogs of the timing belt. But from what you described and saying no compression in the passenger side, that points toward timing belt issue.

Just for the record, it is not a common problems with timing issues at all as long as you replace the belt at the suggested times 4yrs or 60k miles. Chances are the tensioner either failed, belt stretched, or belt was not installed to spec.

How old is the belt?

When was the last time it was replaced?

And last thought, I know it may have been a desperation move, but do not take your car to firstone, especially a z. No disrespect if anyone works at Firestone, but generally these are guys that just started in the industry, have minimal training, and honestly most just don't care. I only say this cause I worked at one when I was a teen just starting out. Yes there are some really good mechanics that work there, but few and far between.

OUCH...a lot to look into here potentially and sorry to hear about Firestone. I had a similar experience with a waterpump replace with 120K included that went south quickly, took three tries and they tried to charge me for rework of their own faulty installation and later breaking of my radiator which was replaced unknowingly by me and despite my request for OEM, with a non-OEM rad. That experience began my Z32 journey back in 2005-2006 and I have never went anywhere except a Z specialist since, or done the work myself.
Anyway, back to your problem...definitely check the compression again as a bad reading(s) are common for those who would not be the best mechanic, start there and with the correct procedure from the fsm.
If you get the same readings (bad whole side, seems hard to be the case) look for other issues such as a massive vacuum leak (broken part/seal/hose) and anything else you can find that is out of spec. Clean any and all corrosion, and do any and all fsm tests you can do...many are DIY-doable.
I agree with Nissanfreak that a good possibility is a bad/skipped timing belt, or next a bad CAS or connection there.
Anything else we might speculate would have to come from test results and reports back on what we have asked already...let us know!

[speeddemon72]

Update: Pulled the timing covers off and the upper idler pulley was f***ed. The little bearings were everywhere. Is there a high possibility that the valves were bent? And also how do I realign all the cams and the crank. Im in a real learning process here and any advice is much appreciated. Thank you

[nissanfreak12]

Update: Pulled the timing covers off and the upper idler pulley was f***ed. The little bearings were everywhere. Is there a high possibility that the valves were bent? And also how do I realign all the cams and the crank. Im in a real learning process here and any advice is much appreciated. Thank you

Go under "everthing you need to know about the Z32" at the home page. You can open the Factory Service Manual and it has a step by step procedure to the timing belt. Honestly, if its your first time I would highly recommend either having a shop that works on these cars or someone that has done it before to help. These can be a PITA to do.

That being said, how are you with mechanics? An honest answer, everyone has different levels.

I would also recommend doing a 120k kit. If the top idler pulley is bad, the rest are not far behind. These kits are roughly $500, so be prepared for that. If you take it for a shop to do it, your probably looking at about another $400-$700 in labor dependent on shop prices.

Now for the valves, if it was at idle and how you described it, chances are low the valves were bent, but I have seen them bend at low RPM's so there is a possibility. Two ways you can find out. Take the head off or do a leak down test. Leak down test is easier and cheaper. You can see if a shop has a scope they can peek into the combustion chamber, but finding one that won't cost $100+ for them just to look is going to be tough or even finding one.

Is the timing belt still on the cam gears? If it is, there is a dimple or "dot" on the front of the cam gears. if you look at the plate behind the cam gears there is a dimple or "dot". These are supposed to line up, for the most part, and that is how the timing is aligned. All the cam gears and crank gear have them. If the belt is still on the cam gears, count the cogs of the t-belt from dot to dot and post the number of each of the following. Count it a couple times, make sure you have the correct number. Do each of the following

Passenger exhaust cam to Passenger intake cam-
Passenger intake cam to driver intake cam-
Driver intake cam to Driver Exhaust Cam-

It can be tricky and you may need to turn the engine to count. The nut is a 27mm for the crank pulley. Use a breaker bar and the 27mm to turn the engine. Do NOT use the starter, you could cause damage if you do. Remove to the spark plugs to make it easier. If you run into resistance trying to turn the engine, stop, do not force it. That means the piston is hitting the valve.

[DCaff300ZX]

Do exactly as nissanfreak says, and note I edited his post to NOT use the starter (he intended to say that I am sure) to rotate the engine.
Checking the tbelt alignment and for any valve\piston contact is a critical check that will determine what you need to do, and you HAVE to be correct or you waste all your work if a head is toast, or piston damaged.
He didn't mention and you may already know this, but if needing to rotate the engine to count tbelt teeth removing the spark plugs for engine rotation will ease that effort, and make any internal contact more noticeable so you can stop before causing damage yourself inadvertently.

[nissanfreak12]

Yup, was supposed to say Not use the starter, thanks dcaff for catching that .