Trouble starting after lower and upper intake manifold gaskets replaced

JOSHXM

MEMBER
1994 BUICK CENTURY
6 CYL
FWD
AUTOMATIC
74,020 MILES

To make a long process short- I removed every component that would keep me out from the lower intake manifold--fuel rail assembly, ignition coil, alternator, power steering pump, upper intake manifold etc.
Anyways when the moment came to finally getting the gaskets replaced I succeeded, and proceded by putting the push rods back in place exactly how I removed them only doing one side of the block at a time. Since I have a v6 it was pistons 1, 3 & 5, the closet to the radiator. And then I did the other gaskets(after I torqued down the other side to specifications). Dont know if I was supose to do that or not. The push rods sat in the lifters appropriatley and in the rocker arm galleys. The next thing I did was put the whole engine back together and tried to start the car. Well it didnt start. We called a friend and he said you have to tighten each rocker arm with its piston in TDC. Ok well I thought that was the reason so I took off the valve covers only, loosened the rocker arms on the front side first, put each piston at TDC and adjusted the rocker arm torque for BOTH push rods per one piston. Then I moved on to do the next piston and then the next and then the next in NO specific order. After was all complete the car still did not crank.
I am completley stumped and I dont know what to do. I reloosened the rocker arms to check if the push rods were bent and nothing. PLEASE ANY HELP WOULD BE WONDERRFUL. THIS IS THE ONLY TRANSPORTATION ME AND MY FIANCE HAVE.I AM FAIRLY SKILLED IN MECHANICS. BUT PLEASE HELP!

2 Replies

JDL

MECHANIC
16,098 POSTS

Are you saying it cranks good but won't start? I can't tell what you've done from here? If it cranks good, do you have good spark at the plugs? Good fuel pressure, use a gage. Good compression?

Was this

answer

helpful?

Yes

No

Friday, November 19th, 2010 AT 3:20 PM

ERNEST CLARK

MECHANIC
1,730 POSTS

Yours is a very simple engine to work on. If you torqued the rocker's down with each cylinder at TDC, then I'd say you got that right. You can double check by doing a compression check on each cylinder. If compression measures to spec, you're good.

If you are good, then you want to do a regular "No start" procedure.
This begins with checking for spark. No spark will be due to the following:

Bad coil, loose/broken wires/connectors to coil, or no signal to the coil. No signal to the coil will be due to a bad crank/camshaft sensor not sending a signal to the computer, or the computer itself, or the wiring/connectors.

If you have spark, then you check fuel. Use a pressure gauge to measure pressure from the pump. If no pressure, pump is bad or wiring/connector, relay, etc. If pressure is good, then check that the injectors are firing. Use an automotive stethoscope to listen to each injector. If they're not firing, then you need to check wiring/connector, computer, sensors, etc.

If you have spark and fuel, and compression, then your engine will fire no matter what. Doesn't mean it'll run good though. So you are obviously missing one/more of these components. You'll just need to do a process of elimination. But don't forget to double check your work and make sure all wires/connectors are plugged in.