Greetings,

As the title says i have problems with my 92 *cough* Roadmaster and would appreciate some help. It has a 350 and I assume the TBI system is roughly the same as a Camaro ( I do own a 87 Camaro but it has a Quadra jet carburetor so it won’t give me any TBI problems )

The problem started with the car surging and then stopped. It was possible to crank the engine but it did not fire up. When we checked under the hood there was a crack in the ignition coil and there was electricity jumping from the crack to the metal frame that surrounds the coil when we tried to start the car. Quite nice lightning show but definitely not working as intended.

After replacing the ignition coil the car still don’t fire up. It does not even try to start, the engine is just cranking.

The things we have checked so far are:

-The fuel pump buzzes for 2-2,5 sec when key is turned. I have not tested fuel pressure yet since I do not have a fuel pressure gauge and they are not growing on trees in my country.
-Tested with a new fuel pump relay, no go
-If I pour fuel into the throttle body the car starts and runs with normal idle until it have burned the fuel. Pumping the gas pedal does not make the injectors spray any fuel.
-When engine is cranking fuel is dripping from both injectors. Keeping the gas pedal floored or pumping it makes no difference.
-Tested with a new MAP sensor, same problem
-I have checked the ALDL codes but it is only flashing code 12 the entire time.
-I have tried to use a test light to see if the injectors get signals but got no light at all ( it might also be that I failed completely getting connection with the test light ).

Since the car starts when fuel is poured into the throttle body I assume that ignition is working as it should and that it narrows the problem down to either fuel delivery or injector performance. This leads us to the questions:

- What can be the most likely part to cause this kind of behavior? TPS, fuel pressure, fuel pressure regulator, grounding, coolant temp sensor, Santa Clause?
- Is there an easy - and fail proof - way to check the injectors and injector signals?
- Is there any other sensor signal needed to the ECM before it activates the injectors?

Any tip and ideas except "Throw a match in there and call your insurance company" is highly appreciated.

/Peter

 

The best thing to do is go and rent a fuel pressure tester. I just had the same thing happen to me. The pump would come on but no pressure. There is a small rubber hose that connects the fuel pump to the sending unit inside the tank. That hose was had basically desinigrated and the pump was just pumping fuel back into the tank. Until you check the pressure you want be able to trouble shoot much further.

 

Ok, thanks for your help.

I will start with getting hold of a pressure gauge then and see where this takes me.

 

Update please? Mine is having the exact same problem, all the same tests, except I just redid a bunch of wiring (and yes, I did check 30 thousand times to make sure it's right).

 

very common problem