87' GMC v1500 GM crate 350 swap, won't start

[bd]

I think you missed the whole verify your TDC mark post or you are just ignoring it. Until you have verified that you are going to be spinning your wheels.

In the post before I mention very first thing we checked the timing.  We pulled the plug and insured it was on compression stroke.  From there I cranked it over by hand just enough to get the balancer mark to line up.  We then rechecked the distributor, found it off a tooth.  Pulled the dizzy and got it set correctly.

We then tried to start it with no luck.  Pulled the number one plug again to insure compression stroke with the finger and lined the balancer back up.  Pulled the dist cap and insured we were still where we wanted to be.

Am I missing something?  Is there something else you think I need to do to insure tdc?  You want to borescope it or something to insure the keyed balancers marking is in the correct place?

Realize that we base recommendations on what you tell us.  Any assumption(s) that you make in your narrative is missing information.  A few situations will result in the balancer timing marks being off (e.g., slipped balancer ring, replacement balancer with timing mark positioned for different year application, incorrect timing tab for an otherwise correct year balancer, excessively worn or slipped timing chain).  For example:

   The image illustrates two timing tabs that are used for different year applications.  The balancer can be correctly clocked only for one tab or the other, not both.  Using the wrong timing tab for the balancer will throw the timing off by roughly one distributor tooth.  On the other hand, if the timing chain has slipped, the balancer mark will be retarded at TDCC.  If you rely on the timing marks with a slipped chain, ignition timing will similarly be retarded.  You get the idea?

According to your description, you verified the timing marks based on assumptions that the balancer and timing tab were in perfect condition and properly matched by year.  Rotate the engine to verified TDCC based on piston position and then compare the position of the timing marks to verify that they align.  Without such verification the timing marks cannot be relied upon to be accurate and your diagnosis is based on false assumptions that can bite. 

[plowman]

Ok I understand.  Just seems highly unlikely that a brand new crate motor from GM would have an incorrect balancer, or timing mark tab, and no reason or evidence to suspect of a worn or slipping chain.  Just to reiterate this was a brand new GM crate engine from balancer to valve covers and I have not removed, modified, or replaced any of the factory installed parts.

But in order to rule out one more thing I will Get a piston stop to physically confirm tdc.

That being said I am fairly sure the hissing sound coming from the tb while I halve the fuel pump jumped and running seems like a more likely cause, and possibly a more promising place to spend my time.

I appreciate the help as I am truly stuck here.  I apologize if I come off as dismissive, I have a few threads going on different forums and I am trying to keep up and absorb everything, and work through suggestions one at a time to cross off possibilities. I also really like asking question and being perfectly clear on things befor I move forward.  I am pretty much physically working by myself, and i live in the boonies so it takes me some time to get new tools/parts when needed.

I blame any communication issues on the internet and the lack of a face to face dialog.  Haha

[VileZambonie]

A piston stop is not designed to stop the piston at TDC rather it is used as a baseline for calibrating mechanical timing when installing a cam or timing set. Don't waste your money, instead get yourself a flexi-straw or piece of mechanics wire and stick it in the spark plug hole pointed at the piston. Slowly rotate the crankshaft until the piston is all the way up and mark the balancer at the zero mark.

For the record, it is not highly unlikely that they are mismatched, it's quite common actually especially with Mexican blocks. I've lost count of how many I've encountered that do not align. Once you've verified TDC at zero you can properly install the distributor. This whole quality check shouldn't take you very long, so start there before you start firing the parts cannon and wasting your money.

[bd]

If you continue to have trouble AFTER you verify the timing marks....

A hiss coming from the regulator, in itself, doesn't indicate a problem, necessarily.  The TBI regulator returns fuel to the tank in order to manage constant pressure, so there is always a return flow when the pump is running.  Your best approach to determine a faulty pressure regulator (or pump, or filter) is to measure fuel pressure using an accurate gauge.  If fuel delivery to the throttle body is an issue, a pressure test will make it obvious.

[plowman]

I'll look through the drawer and see if I can't find a flexible straw that may be able to do the job.  How much travel does the piston have, or how long of a straw do I need to insure I don't drop it inside the engine?

i really didn't feel like pulling rockers of to use the piston stop so I like the idea of sticking something else in there, was just having a hard time thinking of something appropriate for the job.

I pulled the fuel filter and installed a fitting to check fuel pressure as there isn't really any other accessible places in the fuel system.  I used a friends  known good gauge as the fitting on my brand new gauge was different than the adapter.  It showed the pressure spike up to the 15-20lb range upon firing up the ignition then immediately fell off and was unable to maintain pressure.

So again I think that the last comment was right and it seems obvious to me to be a fuel delivery issue.  As I was changing the pump last time I confirmed the pump was sending fuel out of the tank, I cracked the line after the filter and confirmed I had fuel pumping past the filter.  I haven't cracked the line at the tb as I don't want fuel all over the motor but I am fairly confident the lines between filter and tb aren't blocked.

It sounds as though I have fuel running back in to the tank from the return.

So if I have fuel at the regulator could a bad regulator diamphram cause low pressure through the system while returning fuel to the tank?

After physically confirming tdc, I'm leaning towards tearing the tb apart again and taking the regulator apart and checking the spring and diamphram install I have done.

[bd]

Typically, TBI fuel pressure runs at ~11 PSI, although 9-15 PSI is acceptable.  The fuel pump should cycle on for ~2 seconds before shutting off, if you do not crank or start the engine.  This is normal and expected.  However, 15-20 PSI is not normal.  Either the fuel gauge that you used is inaccurate (likely) or there is a problem with the FPR causing high pressure.  Since high pressure would not starve the injectors for fuel, focus your attention on the diagnostic steps outlined by Vile.  Don't underestimate his experience.