problem 94 chevy s-10 blazer

[legless_express]

ok here is the problem i have a 94 chevy s-10 blazer and the vehicle blows white smoke alot. It isn't oil it smells like fuel i have given it a tune-up and replaced the fuel injector assembly on it and still no change any suggestions also to my knowledge nothing was poured into the gas tank.

[tweston]

I had something like that happen when the vacuum hoses on my transfer case got switched around. I think that tranny fluid was being sucked up into the intake manifold.

[legless_express]

yea like i said it is actually fuel it is actually dripping from the exhaust manifold

[inafogg]

white smoke normally was a sign of the engine burning coolant.have you checked radiator?

[tweston]

You've got gas dripping from the exhaust manifold? That sounds dangerous to me. I'm surprised the truck hasn't caught fire.

[old_master]

Check fuel pressure and the systems ability to hold it. My guess is it drops rapidly indicating a fuel leak under the upper intake manifold. Probably the "nut kit" (fuel lines) or possibly the fuel pressure regulator. Here is a guideline for checking fuel pressure:

Fuel pressure is not monitored by the On Board Diagnostic (OBD) system. Therefore it cannot set a Diagnostic Trouble Code (DTC), or illuminate the Service Engine Soon (SES) light. For example: If the engine will not run, or stalls, due to insufficient fuel pressure, no DTC’s will be set and the SES light will not come on.

Fuel pump operation:
The fuel pump circuits are designed to activate the fuel pump relay continuously any time the key is in the START position. When the key is in the RUN position, the fuel pump relay remains activated provided the Powertrain Control Module (PCM) is receiving a signal from the crankshaft position sensor. If the engine stalls, or is not running for any reason, the PCM will deactivate the fuel pump relay after approximately 2 to 3 seconds. The 2-3 second ON time is commonly referred to as “fuel pump prime”.

Fuel pressure test:
This test checks the pumps ability to build pressure, and the systems ability to hold it. Install the fuel pressure gauge to the test port near the distributor. Turn the key to the RUN position but do not start the engine. While the fuel pump is running, fuel pressure must be 60-66psi. After approximately 2 to 3 seconds, the fuel pump will shut off. Fuel pressure must remain between 55-60psi for several minutes. A drop in pressure below 55psi indicates excessive leak down.

Diagnosing leak down:
External fuel leaks include everything from the pressure line connection at the fuel pump, through the fuel filter, and up to the line going to the injector assembly. Internal fuel leaks can occur at the check valve in the fuel pump assembly, the fuel pressure regulator, the fuel lines under the upper intake manifold, or a fuel injector. Accurate diagnosis for pinpointing the cause of an internal leak, and testing the fuel pumps maximum output pressure requires the use of additional test equipment to isolate each component. In some cases it requires the removal of the upper intake manifold.

Here is a link to an adequate, inexpensive, fuel pressure tester: http://www.harborfreight.com/cpi/cta...emnumber=92699


Post your results and we can continue. Hope this helps.