Hey guys,
My truck starts fine when cold, but is hard to start when warm. After 15 or 20 minutes it's fine.
Once it does start, the motor revs, then slowly comes back to idle. It also stinks like it's been flooded.
New wires, plugs, cap and rotor.

I'm thinkin' my fuel injectors are leaking?

'90 TBI 318

TIA!

 

I don't know why this helps, but I 'think' I stumbled into something.
If I hold my accelerator to the floor, then crank the motor, it'll start.

???????

 

Flooded....

 

Yep, that's what I thought to begin with, but the fuel injectors aren't drippin'.

 

maybe the ethanol is evaporating in the injectors when it sits hot? i avoid gas with ethanol but it cost me about $10 more per fill up.

 

Check for codes and check the fuel pressure

 

"Once it does start, the motor revs, then slowly comes back to idle." This is normal engine operation.

You might want to check out the Evaporative Emissions System. Hard warm starting and strong fuel smell are both symptoms of this system being faulty. There are 3 solenoids on top of the rear of the passenger side valve cover. The one closest to the firewall controls this system. The solenoid is controlled by the SMEC. A faulty vacuum delay valve on top of the canister will also cause this.

The best thing about having TBI is the fact that you can actually see how well or poorly the injectors are working.

 

Well, I rechecked the TPS last night and it's got 4.65 volts with the throttle closed!

I'm off to get another one and will report back.

Thanks for all the input guys!

 

Now I've got a headache.

I replaced the TPS in the store parking lot and checked the voltages, everything was OK.
Get home, try to clear the codes, recheck voltages and I've got 4.65 (throttle closed) again!

Something up-stream causing this?

 

Nope, just two bad BWD TPS's. Bought one from Autozone (Delco) and it's fine (so far).

Now I've got a very low RPM stumble. No codes. Time for more 'searching'.