OT. 5,7 Vortec

Trying to help a friend out she has a 97 Tahoe. Someone replaced the intake gasket now the truck runs poor no power but don't seem to be missing. I would like to cheek timing thinking the distributor is off time. I went on line and half the people say you need a scan tool other half say a timing light also some say you have to disconnect a wire.I am having a hard time getting info on this engine to the point that on some of the sites they are calling each other names.It seems any other type of cars or trucks other then GM I can go online and get great info. Thanks
 
I think a 97 has a paint mark down the mounting surface of the dist.on to the intake manifold, this will be on the back better seen with a mirror. It's about a 1/4" wide and has to be aligned when installed with the rotor in the right spot, if not there's a procedure to follow plus the use of a scanner. Why doesn't she take it back if it ran ok going into the shop?
 
1. Take it back to whoever did the work and COMPLAIN. She paid for the work and it was not done right. They are on the hook for fixing it, period.

2. IIRC when we had to pull the distributor on Dad's '89 for whatever reason, we used a timing light. There was some wire up on the firewall near the top of the engine compartment that had to be disconnected to get an accurate reading with the timing light. If this wire was connected the timing light would read about 30 degrees off. Can't remember what wire it was or what it was called. All I remember is it was some time in the mid 1990's.
 
I had that happen with my vortec with the intake gasket when out. Mine had an intake leak on one of the center ports into the lifter valley and the extra air would throw the fuel mixture off so that cylinder wont fire... Hook a scan tool up and read the codes and see if it is one of the center 4 cylinders missing.
 
Hi
Would I be guessing right, that she doesn't take it back to the shop that did it. Because her buddy Bob smith the layer or accountant. That messes fixing on a Saturday after work, That has no clue what he was doing was the original repairer.
Now it's not right the Garage she told was to expensive to do it won't touch it,And Now it's your problem, as your a good friend?.
And yes I am being serious about this apart from Bob being a lawyer or accountant.

I have had guys pull this on me, when it wasn't right, after they got it done cheaper than my quote or tried them selves, The guys neighbor has phoned and made out it's his tractor thats wrong so i'd go look at it in his shed.

It's not often you find 2 farms in 3 miles that have a Belarus 825, that both have the same thing wrong 4 days apart. Thats about the time it takes to get parts and do it L.O.L. I've seen most of this stuff twice in my career, and it costs a premium to fix the last guys mess or I plain don't do it due to there headaches
Regards Robert
 
Yep,

It's out of time and it needs a sophisticated scan tool to set. Take it to a local shop and have 'em set it for ya.

Allan
 
Simple version is to align TDC timing mark on front damper with stationary mark on timing chain cover, then ensure rotor points EXACTLY at the <8 mark on the top of the distributor base, and snug down the distributor hold down bolt.

(The "8" mark is based on it being an 8 cylinder engine, NOT #8 firing position. There's probably another mark, "6", IGNORE that.)

Here's a drawing...

<img src = "http://ww2.justanswer.com/uploads/VLADGMRU/2010-07-02_120545_dist.png">

How's THAT for simple?
 
the base of the distributor on these engines are plastic & usually break when removing the dist. cap screws. grab the cap with the engine shut off, if it is loose you will need a rebuilt distributor
 

Timing light won't do it (check timing) you need a scan tool to check cam retard offset Google : how to check cam retard offset :

The scan tool will have to have the function test are in trouble shooter to get there...

If its off that bad the check engine light should be on it may not be your issue...
 
I would bet on the distributor being put in on the 6cyl mark not the 8 cyl mark.
 
My .02 worth, here is a simple test to confirm my suspicion Now I'm a bit old school but do you know where the PCV valve is on this truck? I think it is still in one of the valve covers. I think there is also a vent from the engine air intake duct also in the opposite valve cover. You need to pull out the PCV valve and block the location it draws vapor from the crank case. And also block the other vent opening as well. If when you essentially get the crankcase sealed and the engine draws a vacuum on the crankcase while running you can start over replacing the intake gasket again. It is leaking vacuum into the lifter valley. I just used my thumbs or fingers as plugs
 
Did they have the top off the manifold and the injectors out? It is possible to mix up the poppet lines on the Vortec 4.3, 5.0, and 5.7. Makes for weird, hard to diag misfire problems. I have seen it done.
 

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