Gas and oil in exhaust... Halp!

Status
Not open for further replies.
  • Sponsors (?)


Follow up for future readers...

1993 5.0 Coupe w/ 67,000 miles

Decided to do a Heads/Cam/Intake install. Tore the top end of the motor down. Installed B cam with cam gear pointing at 6:00 and crank pointing at 12:00. Put GT40X heads on. New lifters, rods and 1.6 rocker arms. Added a BBK SSI intake and 24lb fuel injectors. Added an adjustable fuel pressure regulator.

Problems:
a) The car won't start and has a gas/oil mix leaking from the front and back of the h-pipe and gas is smelled on the dip stick and thus is in the oil pan.
b) The fuel guage is reading pressure, but immediately after (crank or no crank) the pressure falls off.
c) Water temp (autometer electric) is reading 150 deg and 180 upon attempted crank

Observations:
Gas is OBVIOUSLY bypassing the piston rings. Oil or an oily residue is mixed in with it. The gas leak CANNOT BE FOUND and again is also in the oil pan

Possible Causes:

Upon getting advice from several friends and a ASC Certified master I have come up with 2 possible explanations. Either-

1) The cam and the crank are not timed together. The only way to screw this up would be to not line the cam at 6:00 and the crank at 12:00, or break the new timing chain (double roller), break the cam or break the crank...

Reasons in favor of this explanation include the facts that there is oil in the exhaust which occur only if the head gasket was blown. The only way we can think of to blow a head gasket upon first start up is to misalign the crank and cam so that when the piston is forced down in one cylinder, the others are forced down with it due to the misalignment. The front 4 cylinders except the #1 do not appear to be doing anything as the rocker arms are even with each other and sitting up (valves closed).


2) The oil is actually the residue on the top of the pistons mixed with a flood of gas caused by incorrect timing. Fuel is bypassing the rings.

Reasons in favor of this explanation include the facts that the distributor was installed with the rotor facing the literal number 1 piston at the front passenger side of the motor instead of the #1 mark on the inside of the cap. This would throw the timing way off and you'd actually be many gears out of place.








***Note

I will try tommorrow to get the #1 piston at TDC so that I can put the rotor button facing the #1 mark on the bottom of the cap. This is what I thought was right in the first place and jrichker' "Cranks OK but no start" checklist confirms this. I will disconnect the inertia switch behind the brake light to ensure that no more fuel is sprayed while I try to find TDC by either using a clothes hanger to feel for the top of the piston thru the #1 spark plug hole. The air against the finger trick will not work if the valve is bent or stuck open.

I will put the rotor in the roughly 1:00 position that it came out of and reconnect everything. I will then check that the rocker arms are all moving in sequence. After that I will again put the motor at TDC and try to crank again after reconnecting the fuel, etc. The fuel gauge may be bad. the temp guage may have been damaged or tightened too tight.











Will follow up tomorrow. :)
 
as long as the two dots on you timing set lined up, you cam is in right. also, if its an adjustable set, make sure its the right marks lining up.

the dizzy problem is likely, turn the crank up to tdc and set it right, rotor should be pointing straight back (straight forward if on the opposite stroke. also double check you have the right firing order, and that all plug wires are good and connected.

something that i ran into was an injector that was always open because the connector shorted out (cracked insulation on the wires). doubt thats your problem, but wouldnt hurt to check.
 
Fuel pressure should not emediatly fall off. Yes it will bleed down slowly but if its at 40+ psi and then drops to 0 in under a minute then you have a leak as well (mabey the issue the SSI is known for). As for the rest, I would do an oil change and make sure the dizzy is in the right oreintation. Shouldnt be too bad bro :nice:
 
The dizzy rotor needs to aim at the #1 plug wire with the #1 piston @ TDC Compression stroke.
 
1. Get Cylinder #1 at about TDC with the finger-over-the-plug-hole trick;
2. Look at the timing marks on your harmonic balancer to see if you're on the compression or exhaust stroke to know whether or not you're 180* out;
3. If you're right at 0* BTDC on the timing marks, go ahead and stab your dizzy and make sure it's pointing to Cylinder #1;
4. Crank it and turn the dizzy just a smidge at a time until you get it timed close enough by ear to get it fairly close;
5. Finish fine-tuning the timing setting with a timing light.

If your timing winds up being dead-on at 10* BTDC (or whatever you prefer to set it to on your combo) and it still runs like crap, I would look at the intake as being the issue. The fuel pressure bleeding off rapidly is NOT a good sign and would seem to indicate something is VERY wrong with the fuel system - maybe a crappy fuel pressure regulator? An injector stuck open and dumping fuel? Manufacturing defect with the intake/fuel rail? :shrug:
 
Status
Not open for further replies.