I will try to keep a long story short. This is the same '97 850 T5 that I started working on a few months ago to correct multiple oil leaks.

In addition to replacing the timing belt and tensioner, both rear cam seals were replaced. The front cam seals were not replaced but checked for leakage and required the front timing belt pulleys be removed.

I did not notice when taking the cam pulleys off, the screw holes in the pulley are slotted and not perfectly round. Although the cams were locked in position, there was a time when the locking tool was removed and the cams did rotate a little bit before the timing belt was replaced.

Ultimately, the timing belt was put back on with the crank TDC and cam pulley hash marks in proper position. The engine was manually rotated twice and no valve knocking was felt.

Now, with everything back together, the engine cranks but will not start. The fuel rail has pressure, the injectors are functional with gas going into the cylinders, there is adequate spark and the engine produces no knocks while cranking. Matter of fact, when cranking, it sounds like the engine is just ready to begin firing on it's own but just wont get to that point. Read somewhere that a tablespoon of motor oil placed into each cylinder will help pressure up the cylinders helping the engine to start but all that did was smoke up the garage. Did double check that all vacuum lines and other sensors and valves that were removed were back in place.

Ran a cylinder compression test last night as best I could with the spark plug threads buried as deep as they are and the threaded nipple being substantially shorter. Cylinders 1 - 5 read 130 135 135 100 125 which from what I understand is pretty low. I don't have any prior readings for this engine but I can tell you there were no performance issues before it was taken apart.

Big Question: Is it possible that the intake or exhaust cam could be mispositioned and causing the valves to be open just enough at some point during the stroke cycle to create compression readings this low ? If so, does anyone have any ideas of how to determine how to go about correcting it ? I am open to any and all thoughts at this point because taking it to the shop is going to feel like the ultimate defeat.
Thanks for reading.

 

A compression test on a cold engine is worthless. I did one on my 850 and got 60lbs average. Once warmed, I got 130 across all cylinders. Are you sure you didn't forget to connect something? like the plug or coil wires, a sensor like TPS etc. if you took off the rear cams seals you had to pull the distributor and the cap. if you used the Haynes Manual, the plug wire order on the cap is WRONG!!!!

 

Thanks for the advice on the compression. I checked all my connections twice since I still had them marked but will do it again this weekend. I used the numbering that was on the new Bosch distributor cap just installed but will double check the spark plug order again.

 

When you find the problem please let us know. Doing my T belt soon, bigger job than usual for me so all the info I can get I'll take.

 

Could have messed up your timing too.

 

Crank TDC: did you go by the rope trick or timing mark on the Crankshaft pulley?

Are the A-camshafts and the B- camshaft pulleys aligned?

If these are all ok, then yes, it might be the dizzy...

Rickford -- if you don't need to do seals, timing belt is pretty straight-forward.

 

The rear cam seals were replaced before releasing the timing belt so it acted as the cam lock. My home grown cam locking tool was then attached and the timing belt and pulleys were then removed. Unfortunately for some reason, the cam locking tool was removed before I was completely done working on the engine front.

Rope trick ? Used the marking on the crankshaft pulley against that on the block.

The intake and exhaust cam pulley hash marks are currently dead center to the timing belt cover notch marks.

Dizzy - you are right on here. I'll fill my boots with this again over the weekend and post an update. Probably picked the wrong week to quit drinking !

 

That wasn't the question. The question is -- since you took off the pulleys, are pulleys and camshaft are aligned to each other? There is a write-up in the stickies how to do that.

"Dizzy" is abbreviation for "Distributor".