Sometimes it will, most times it wont

[SHOwener1986]

I have a 93 atx and it wont start most of the time. And when it finally does start it runs terrible and will soon stall. I bought it off a guy for 500 bucks cause he couldnt deal with it. He had alot of things checked to no prevail. I took it cause I have another SHO to swap parts off of. What could it be??

 

[shofun93]

Start with all your regular stuff plugs, wires, plug well seals, and put in a FULLY charged battery. Also pull the codes for us and we will get a better idea.

 

[91 SHOplus]

Do a search here on "firing order". The helms/chiltons manuals list it incorrectly. Others have posted the correct order.

 

[trueSHO]

Like Shofun93 said, make sure you have a good, fully charged battery, alternator maybe? The fuel pump may also be a problem, and i'm not sure if an SHO has a fuel pump relay, but if it does, check that out before you spend the money for a fuel pump, it would be cheaper, but like i said i dont know if they even have a fuel pump relay. other wise, plugs, wires, firing order. This could give you a big headache if it hasn't already.
Now that I think about... my buddy had a 91 that wouldn't start for a few days, then never had a problem with it again, so...

 

[Mr Anonymous]

Grounds, grounds, grounds. Check the integrity of the ground strap connection from the firewall to the intake, make sure the two bolts are in place securing the crossover tube, and make sure all four screws holding the DIS module are in place. Also check the negative battery lead to the block and the aux ground to the fenderwell.

 

[Mels]

'Wener, where in CT are you?

 

[SHOwener1986]

one more thing, when it stalls it wont start again. any help? I havent had it tested with a diagnostics computer.

 

[SHOwener1986]

Im down on the shore...New Haven area. in reply to Mels

 

[CrispySHO]

same thing happened to me... turned out to be short in Crank Position Sensor Wire...
i would recommend replacing it =] although its hard to get at... after i replaced mine it has run just fine for past almost 2 months

 

[Sho-N-Go]

Does the CE go out while cranking? was the firing order right?

 

[SHOwener1986]

Where is the CPS located and what does CE stand for. Help a noob out! I have another SHO to steal parts from and the firing order is correct with no oil in the wells. Also it has the correct amount of fuel pressure.

 

[SHOwener1986]

Ok guys I got the codes pulled and it came up with 118, and 636. The computer said 118 is the coolant temperature Sensor, and it didnt tell me what 636 was..Help what is code number 636?

 

[Sho-N-Go]

Does the CE go out while cranking? was the firing order right?

CE = Check engine light it should go out while cranking

 

[khanartist]

Very important, does the fuel pump prime after it has stalled? I just went through two weeks of chasing an intermittent stall problem, that turned out to be the fuel pump relay cutting in and out.

 

[SonicRiot]

There definately is not enough info given to diagnose this car!

You need three things to make a car run: Fuel, Fire, and Compression.

-Run a diagnosis on the charging system and battery.
-Visually inspect all plugs and wires. Pulling the plugs will be very telltale in your diagnosis. Carefully inspect each plug for color, gap, carbon, etc. You can TRY arcing out the spark on the block. I have done it, but it is dangerous. So it's at your own risk...
-Run a diagnosis sequence on the DIS system with a multimeter. PheonixSHO has a good, clear procedure to follow.
-Make sure the firing order is correct.

If all passes, you have fire. Next, inspect the fuel delivery.


-Sounds obvious, but check the tank for amount of fuel
-Visually inspect the fuel lines from the tank to the rail. Listen to the pump prime and depress the schrader valve on the rail to check for pressure. If possible, check the pressure at the rail with a gauge.
-Check the injectors for heavy deposits. Ohm them out as well to check for excess resistance or internal shorting.

If the fuel system passes, you have fuel. Next inspect your engine internals and timing.


-Run a compression test. You will need a compression gauge. Put it in place of the spark plug and DISCONNECT the DIS module. Crank the engine over at least 3 times and observe the compression on the gauge in EACH hole. If the compression is extremely low in EVERY hole and is around the same value in EVERY hole, then your timing is off. Inspect the belt and re-time the engine.

-Next, run a leakdown test. This requires shop air and a leakdown gauge. Bring the piston to TDC on powerstroke. If you hear hissing:
-Out the intake: bad timing or a burnt or broken intake valve (EXTREMELY UNLIKELY, but possible if detonation occured)
-Out the exhaust: burnt exhaust valve or bad timing (but you will hear the intake as well if the timing is off)
-Out the dipstick or oil fill cap: Rings, baby. Time for a 3.2L swap and buildup.
Do this with EVERY hole.






Hope this helps. It's difficult to diagnose a car, but remember these basic principals during a no-start condition. It will save a lot of shooting from the hip and prevent wasted money on thrown-in parts.

Good luck.