Cranks, but wont start...just replaced fuel pump. :(

[Speedie13]

Some of you might already know that my new SHO died on me a few weeks ago on the way to work. For those of you who dont, my new 93 3.2mtx and I were on the way to work when I lost "power" I guess you would say (not electrical power....more like forward momentum). I turned a corner and was getting back into the throttle when the pedal just started heading towards the floor and the car wasnt going any faster, i downshifted and gave it gas again with the same result, the car rolled a little ways and then died. Not to throw any wild ideas out but Im pretty sure the oil light flashed at me while the car was dying.
FWIW ive seen the oil light flash at me before on my 95 when I slip the clutch and **** it.

Anyhow, I ordered a new fuel pump and installed it tonight. Car still wont start....just cranks and cranks and cranks. I hear a few clicks when I turn the key on but no humming sound from the pump like my 95 has when i do that. The thing is though that I tried three other cars tonight (a Gen2 RX7, 90something Civic hatch and a 91 Civic Si) and none of them made any noise from the pump but all started and ran no problems.

So im left with nothing. Im stumped. I am leaning a bit towards a starter but would I still get a constant cranking with no start or would it not crank at all? And to me it just feels like the car isnt getting gas or something. All the lights come on, i have 100% full power.

I usually have a pretty decent handle on whats wrong since Ive had lots of things go wrong with my 95 but this one really has me stumped and since i most likely spent money on a fuel pump i didnt need im not too amped about spending more on parts that wont fix the problem.


Any advice is greatly appreciated.

 

[Speedie13]

Ok well after reading a few more threads I have developed a few more ideas...

CPS - Could cause the no starting but cranking problem??
No Fuel Pressure - I might check the valve on the rail to see if I have any

I think thats it so far....any thoughts?

 

[projectSHO89]

Was it a right or a left turn that you went around and the car died?

Did you check the inertia switch in the trunk (left side, hole, push red button down).

Quit hanging parts on the car. Need to diagnose it first.

If the fuel pump is not heard, it's not running. There will be no fuel pressure until it does run. Until your fule pump runs, the engine will never start.

Sounds like your starter is woring just fine.

Steve

 

[SHORANGERBIRD]

-Also dont forget the multi function relay up front that powers the pump. if it ain't workin', pump wont work...

 

[Speedie13]

Thanks for the input guys

I talked to a few guys at work about it and Im going to check the pressure and spark. I will check over what you suggested as well. Thanks again. I will post some updates later this week.

EDIT: I was turning right. Havent checked the inertia switch or multi-function. I just wanted to get some input before I started messing with other things.

 

[bertha66]

When my 93 SHO's fuel pump relay went out, I diagnosed it by running a hot leed from a keyed port on the back of the fuse box to the infeed line on the inertia switch to bypass the relay and put power to the pump and the car would run.

 

[Super Matty P]

where is the fuel pump relay located? I looked in my computer at work and couldn't find an available aftermarket relay for the fuel pump.

 

[SHORANGERBIRD]

-Core support, under plastic cover with labels on it....

 

[SHO#7]

where is the fuel pump relay located? I looked in my computer at work and couldn't find an available aftermarket relay for the fuel pump.

It is part of the IRCM. Which is mounted to the core support. Under the Vaccum hose route charts.

You can check to hear the relay by grounding one of the pins on the EEC port. ( Where you check your codes. )

The EEC has four slots on top and two on the bottom. Ground the top right one and that will trigger the fuel pump relay. ( I assume the key must be on )

_ _ _ _ <---- This one

_ _

Mike

 

[Speedie13]

UPDATE: I worked on my car a bit more today, with no real results... I did however try some things:

Checked the Inertia Switch - it was up, pushed button down.
Grounded out top-right EEC port - All I heard was clicking from up front when I turned key to ON.
Checked for Spark - Had it, no problems there.
Dropped tank again and checked all lines and connections - all seemed to be fine.
Disconnected fuel line from Fuel Filter to Pump, turned car over - no fuel coming from the pump.

The pump still doesnt hum when I turn the key and I (obviously) have no pressure at the fuel rail....so....whats next?

 

[bertha66]

Try as I said earler, hot wire the pump though the inertia switch and see if the engine runs.

 

[Speedie13]

well well well....how very interesting...

Ok so after I reset the inertia switch, tried grounding the FP on the EEC and all that business I decided to take out my NEW Walbro fuel pump and hook it up to a power source to see if it would kick on....Well WTF!?! The pump does NOTHING, well except get hot after a few tries.

Hmmm....defective pump?

So I decided just for the **** of it to try my old (the original) pump on the power source and guess what? It fires right up and after about 6 tenths of a second I have it off the power source and have a working fuel pump

Let this be a lesson, dont just buy something until youve tried EVERYTHING, unless of course you have the money and WANT to buy things of that nature.
So anyway now the car starts up just fine and runs great, with just a small amount of time to get it started after it sits for a while. Still probably cranks more than it should, but I will deal with that issue later.

With my luck I should have just automatically assumed the new pump was bad and tested it out right from the start...silly me.

Now I guess my question becomes....What would cause an inertia switch to just turn off? I thought they were for accidents and things like that....not making right turns

Anyway thank you all for your input, it was very useful!

 

[projectSHO89]

Now I guess my question becomes....What would cause an inertia switch to just turn off? I thought they were for accidents and things like that....not making right turns

A right hand turn causes the objects in your trunck (if any) to thump against the left wall of the truck, often tripping the switch.

Steve