Help tough start... running rich?

[jvc93//klze]

I just picked up a 93 White SHO. Its the 3.2 ATX.


It is difficult to start and seems to run rich. The car starts eventually but takes some time to get running. It will start for a second and basically stall. I have found that giving it a little gas helps it start. It occasionally backfires when trying to start it. It likes to start for a second then die.


Additionally the tach works intermittently. It starts right up when the tach doesn't work. When the tach works it seems harder to start. The car also studders when it is first started. After it warms up it gets its SHO power back.

I changed the camshaft position sensor. It had no effect. What else could be the problem?

 

[johndallara]

SHO issues

run the codes, of course.

Might be a bad IABP valve (which won't throw a code, I don't think).

Also if it is running rich at start, but clears up after a 20-30 seconds, might be leaking fuel injector seals. Mine did this, esp when engine hot left sitting for a while (pressure from rails leaks into intake, super-rich mixture at start-up, confuses computer). My 95 ATX did this.

JD

 

[jvc93//klze]

The only CEL code is for the oxygen sensors.

I'm trying to keep the repairs as inexpensive as possible.

 

[jvc93//klze]

I tried running premium fuel and the car runs better, but still has hard starts.

 

[Kens1992mtxSHO]

How old is the gas in it?

*EDIT* you beat me to it lol.

Spark plug wires in the correct order?

 

[jvc93//klze]

Gas is good and plugs in correct order.

 

[jvc93//klze]

The spark plugs are old. I may try changing the plugs and wires. I also heard something about a fuel pressure valve possibly being bad. Ill have to look into it.

 

[1bad98SHO]

Check resistance across the coolant temps sensor with known values. Sounds like a bad Coolant Temp sensor to me.

 

[jvc93//klze]

Check resistance across the coolant temps sensor with known values. Sounds like a bad Coolant Temp sensor to me.

I've had a bad coolant temp sensor in another car. I'm pretty sure the coolant temp sensor would only affect the car's starting on warm or cold starts. In my case it intermittently has trouble starting when the car is warm or cold.