Good day folks!! I got this 87' fc with a hks PFC fcon with fcd, full rb exh.,hks to4e.my problem with this car is it's running wayyyy to damm rich! So bad I did a 35 mile trip with just a shy below half tank and by the time I got there it was empty!! WTF !! The previous owner said the o2 was brand new,it looks new! What's your input on this! I can smell raw gas when at idle!

 

check the fuel line and make sure its not leaking. check to see if o2 sensor is hooked up, check to see if your coolant temp sensor is bad, check airflow meter.

 

As usual, Cygnus beats me to the punch.

Some day I shall have my revenge, Sir Cygnus!

:shakesfist:

 

 

Like a hatter, my friend.

Like a ******* hatter..... Care for some of my special tea?

 

jesus.

how are your injectors?

 

rebuilt by RC

 

Are you sure your fuel level sending unit is operating correctly? Have you checked your pulsation damper, as they are notorious for leaking and causing engine bay fires? We lost an 87 TII due to such a leak.

 

Which one is the coolant temp sensor?

 

On the back of the water-pump housing, right below either the filler cap, or the bend, depending on what you're driving.

 

So it has a T04E turbo and the only fuel control used is an FCON? Did you make these modifications to the car, or did a previous owner? In order to not pop with that setup, I would expect a high-flow fuel pump and some larger injectors. Whether or not the car has an aftermarket FPR to control such a pump (stock FPR gets overwhelmed), or reasonable tuning with the FCON are some things I would consider right away.

 

interesting interesting interesting.

 

Realistically, the turbo, itself is an ALMOST irrelevant factor in this equation.

The original post stated that it was raw fuel, at idle - There-in removing the turbo from the equation (the only time THAT would come as a factor is when it's under boost).

Since it's dumping hella rich ALL the time, specifically at idle, I would start from the bits that're actually under affect of the idle state:

Don't forget that there're several different little factors that go into an even AFR, at idle.

Cygnus' post - as much as it kills me to say this (since that guy's been beating me to the punch for YEARS), is where you need to start.

Since I didn't see if you had an A/F gauge, or not, I'm going to suggest you get one.... 'Course the FCON> FCD has an visual output for it.

Idle the car for a few mins, let it get past the initial. high-RPM startup, and look at your AFR. (post idle number!)

Since you're dealing with an aftermarket tuner, I'd say check your maps. It almost sounds like your duration is set a little long - good setting for interstate, top-end pulls.

 

I purchased the car with those mods already installed!it has a cosmo fuel pump,injectors were rebuilt from rc,it's only running 10psi. I'm looking at the mega squirt pnp for this setup.

 

the previous owner had a afr guage installed but never hooked it up! I already ran the wire back into the car all I have to do today is wire it in to the guage.

 

When was the last time you pulled the fuel-sender and checked the fuel filter?

 

I never did! Where is the pump located?

 

In the tank. It's the fuel sender. There's a panel with several 10mm (I think) bolts. Make sure you're outside and/ or have a GOOD fan blowing through the car. When you pull the access panel to the tank, it'll REEK of gas.

The sender has a sock on it, in-tank, and the second filter, if so equipped, is kind of below the master-cylinder, on the firewall.

While the sender's out, get a good flashlight (by good I mean a WHITE beam - LED lights are great for this) and shine it into the tank. You may see a bit of crap, crud and sediment, trucking around the bottom of the tank.

As well, if you have one of those nifty magnetic thingies, you can put it down in the tank and see how much metallic crap you pic up. Chances are, there's rust and **** in there, as well.

 

Cosmo fuel pumps will behave pretty well with the stock FPR; I was mainly thinking of the commonly used walbro 255. Walbros and other similar pumps are great for raising fuel pressure at idle and under vacuum, which means extra fuel dumped into the engine.

Depending on wheel size, a T04E turbo can produce 3-400 whp, which is far more than stock 550cc injectors can support. You mentioned the injectors were rebuilt by RC, but I would expect to also find that they're larger than stock. If the previous owner installed larger primaries and secondaries, but did a horrible job of tuning with that FCON, you could be looking at lots of extra fuel being dumped in.

 

well I changed out that damm coolant temp sensor and like a dumb *** forgot to disconnect the positive battery terminal and blew the damm main fuse when I was removing the alternator to get to that sensor.I replaced it and it worked!!No more running rich,starts everytime,runs smoother!thanks guys for your fast responce and input on this!Im about to check the fuel pump filter and drag the tank for rust and un-wanted junk in tank!

 

Gigetty.