Timing set alignment?

[Chuck Leeper]

GN/S-10 from Hell!!

Russ, I think there's a clue in that it's backfiring out the tailpipe.
That tells me there's fire to the plugs, there's fuel from the inj's.
If it's firing out the exhaust, then there's only 2 things that cause that.
1. Lighting the fire at the wrong time.. IE: the exhaust valve on one of 2 cylinders is open.[Waste fire system] Wrong valve timing.
2. The valve timing is right, but the ignition timing is not.

Vapors from the crankcase by just cranking the engine cold is not normal!!

If you have changed modules or coils, did you hook the wires up to the underside of the coil correctly???

A dumb ? on my part. Does the FP prime and then shut off?? What does the PSI go to when you turn the key and the pump starts? Does it stay there or close when you go to the start position? Have you tried to jump the pump to stay on ?
Could be the psi is falling and the inj's are not operating like they should....?? Just a guess

 

[MSDGN]

Wait a minute!...you said you set the crank sensor with the interruptor ring in the slot closest to the electrical connector...
from experience it will never start that way...it has to go in the slot farthest from the elec. connector... if you say it won't work that way then something is wrong with your crank sensor...

 

[Chuck Leeper]

Crank sensor

Scott is RIGHT ON!! I saw that and ignored it, not thinking that it had not already been "checked"!! DUH
I have a "collection" of sensors and mounting brackets. [The brkts are NOT the same]. 1 bracket has a "jaw width of .870" and uses the plastic sensor ONLY. Bracket #2 has a jaw width of 1.400", and uses the plastic sensor encased in a metal hsg. The plastic sensor BODIES Are the same. The metal encased sensor has a "grip length" of 1.100". [MORE ADJ] The 2nd is plastic only and has a "grip length" of .780".
The OUTER slot is the active signal slot, NOT the slot closest to the connector. I can "ID" w/ that, as I had mine in the wrong slot when I changed covers!!
I also had an issue w/ the metal sensor assy having the plastic part inside coming loose. Took it apart,[it screws together], and "fixed it".

 

[Steve Wood]

I sent him a picture last night of the correct positioning....as no one else commented on it, I figured I must be nuts...but...none of my cars will run if it is in the other slot...you know how I know that...

 

[S10xGN]

DOH! (DOH! DOH! DOH!) I mis-spoke about the crank sensor - it's in the groove farthest from the electrical connector.

Chuck - the fuel pump is right on (pumped out 12 gallons in less than 10 minutes!) It has the 2 second prime and runs as it should - producing 44# line off pressure. I haven't actually *changed* modules, just the whole assembly with the module/coilpack. I'm with you on the vapors - I've built a bunch of engines and never had that happen before. While the pan was off, I looked up at the piston bottoms just to make sure and they all looked good. My compression check is low, but I'm thinking the rings aren't sealed yet (comp check was 110# - 125#).

When I get "recovered", I'm going to try Jim Testa's ploy a few messages back - about pulling the plug and checking timing and all.

Later,

 

[Chuck Leeper]

Ring seal

Russ, I doubt the added sealing you may see w/ more run time will bring the compression up 35 to 50#. It appears theres alot of variation in the readings you have gotten. That engine should see something in the 150+ range.
You DID block the TB open and have all the plugs out, the batt was charged, when you did the test, RIGHT??.

One thing that can make the compression funky??? The cam is off!! A good indicator is that the cranking RPM seems to be too high.
Have you gone back to "square 1" and put all the stuff you have changed back to where it was when the engine ran??

wrong p rods, etc, holding the valves open?/ Low compression and backfiring out the tp is another indication the valve train is FUBAR...

 

[S10xGN]

On the comp check - no I just checked it with the plugs out - 4 or 5 spins with the throttle closed - I knew better, I was short-cutting here just to see if I actually had ANY compression. When I blew the HG's out, 3 cyl's showed "0" and it still ran.

I am *supremely* confident that the cam is right...

Here's all the stuff done since it last ran:

• Jason's powerplate (didn't remove)
• ATR PCV check valve (didn't remove)
• new Delco O2 sensor (didn't remove)
• MSD 50#er's and PTE chip (also have and tried a JayC chip)
• new IAC motor (changed)
• new Autolite #24's (@0.035") (re-gapped to 0.030")
• checked for timing gear alignment, OK (re-dgreed & still OK)
• new GM front cover (self-machined for Weber roller cam thrust setup - set @ 0.015")
• pulled thrust nose, cam sensor gear, "eccentric spacer", timing gear, & thrust spacer - did Weber's "oiling mods" and re-installled
• checked timing gear alignment (again - OK)
• new Optima red top battery (tried a different batt)

I had already sold my (working) red-stripes and chip, but did try the stock injectors and chip to no avail.

I checked the pushrods when I first put in the Comp roller, they had from 0.014" - 0.048" preload (not sure why the large variance), but it did run OK w/o any valvetrain noise. Could the tight preload on some valves have caused the burbling (miss) sound from the tailpipe at idle? Hmmm, maybe I'll buy an adjustable pushrod and double check ALL lengths...


Thanks!

 

[Chuck Leeper]

HHHMMM??

I see no items that could be the cause 4 no start.
Only real "changes" are the labor items....
The variation in preload could be :
Using stock rockers... some aren't even CLOSE on ratio.
Heads milled crooked.
P.rods not all the same length to begin with.

The TPS reads .42 range when cranking?? If not and it's FUBAR and reading way high.. the PW on the injectors could be waaayy too long??? Have you tried to start it w/ the pedal down to force it to "clear flood" mode??
Were the 50's new?? IF NOT, pull them and send tem to me and I'll run them on the flow bench. I have seen even NEW inj's that are stuck shut! Very frequently, I get used inj's that someone had lying around, that have dried gas and crap in them and they won't EVEN think about working!!

ALL goes back to the FT of the engine, doesn't it??

 

[Steve Wood]

That is a thought! I gave someone a set of blue tops that worked perfectly for me. They had been bagged up for about six months...every one of them was dead as doornail when installed in the next car.

 

[quickt]

There is one other thing might be longshot but here it goes. I have seen the coil pack installed backwards on the plug wires installed with the numbers on the coil pack. That will do it for sure. The only other time I have seen this was a crank ring had hit the magnet on the crank sensor and broke it. There was a piece of the magnet stuck the inside of the ring. That caused all sorts of funky stuff but the car never did start and did backfire.

 

[S10xGN]

The TPS reads .42 range when cranking?? If not and it's FUBAR and reading way high.. the PW on the injectors could be waaayy too long??? Have you tried to start it w/ the pedal down to force it to "clear flood" mode?? Were the 50's new?? IF NOT, pull them and send tem to me and I'll run them on the flow bench. I have seen even NEW inj's that are stuck shut!

Chuck & Steve: TPS is .44; Have tried "clear flood" mode and it does make a different sound while cranking - spins over normally as long as the pedal is down, but if you lift while cranking it reverts to the "high compression" pattern; The 50#'s were new from PTE, they were dated 6 months prior so we built a test rig from an old air filter/reducer, hose, and clamps and actually tried them on the bench with solvent and a 9V battery "harness" - they all blew good.

Lonnie: That is what a friend here in town was telling me to look for, but I don't see how the coilpack could "rewire" itself - I certainly haven't done anything except unbolt the entire coilpack/module/mount bracket with plug wires still on it and set it on the bench. We did swap over the wires whenever we changed to the used coilpack/module I bought here from John DiCarlo. Does the module connector face the DR side (mine does)? I can check that fairly easily - I do have a factory manual with the wiring info for the coilpack...

 

[chiken]

Steve,
could you please send me that picture also?

 

[Iceman]

Did you ever get it started?If so what did you find?

 

[Chuck Leeper]

Reverts to hi comp?

You wrote:
Chuck & Steve: TPS is .44; Have tried "clear flood" mode and it does make a different sound while cranking - spins over normally as long as the pedal is down, but if you lift while cranking it reverts to the "high compression" pattern

If that's the case, it sounds to me like the cam is in wrong...You have the " airflow path" open w/ the T/B open and enough air is getting thru, albeit at the wrong time to allow the engine to spin at :higher" speed. Shut down the air and it goes to bucking the starter... SUMPTIN'S OUTTA TIME!!..

What's the latest??? ??

 

[Steve Wood]

I believe Russ said he had degreed the cam more than once and events were happening correctly.

But, I agree....it sounds like something is out of whack timing wise. I wonder if this cam is ground for a buick? Meaning, are the timing events in the right place. Degreeing to the cam card won't help if the cam or cam card ain't right in the first place.

 

[Kid with a toy]

Russ?

 

[FJM568]

I think he only degreed #1 in, right??? #1 could be degreed in right, but the rest of the cam may be ground wrong!!! I would check the rest of the cam...Degree the rest of the cylinders in to see if it is ground wrong...

 

[S10xGN]

Errr, I'm still takin' a break working on my son's MCSS and other jobs that have somehow managed to stack up around here. I haven't done anything but trip over a certain white truck with Buick motor inside... Yes, I am SUPER confident the cam is degreed properly and the engine did once run with the cam that's in it now. Just out of curiousity, will these engines start without any turbo ducting installed - i.e., just the exposed throttle body? I'll prolly pick back up on it after next weekend.

 

[Steve Wood]

Talk to John Spina and see if he will let you try his latest invention which is the quick start device...go to tbs.com and read about it...it might just prove something.

 

[FJM568]

The ducting from the TB needs to be hooked up to the MAF ducting for it to run...It needs metered air for it to run properly...