hitman

Hi guys. The knowledge base here is awesome and I know somebody here can point me in the right direction.

The TPI is running rich as hell. The emissions sometimes smell like rotten eggs and sometimes it smells like fuel. The check engine light turns on intermittenly so everytime I try to take it someplace to scan the code its not throwing one.
I have been plagued with problems lately. The A/C clutch froze so I put the AC delete pully. The thermostat housing bolt on the intake stripped out and the the car was beggining to overheat. The state inspection has expired and I cant get legit till I have these items fixed (minus a/c).
What would cause a TPI to run so rich? Oh yes, I tried the cruise control one day and it wouldnt work. When I tried replacing the thermostat, I could see where liquid (most likely fuel) was running down the passenger blade opening.
Come on guys, I know you had to have come across this before.
A little background. The car was parked for a bout a year and just before it was parked the car got a new ign module, coil pack and cap/rotor set. The cats are Magnaflow and are about 2yrs old. I know I have at least 1 new o2 sensor. I am just stumped.
Help me out fellas. Money is tight and right now this is my only means of transportation. I cant afford to buy another car.

Oscar

I would start by replacing the O2 sensor and go from there.

O2 sensor can cause a world of problem's, can make the car run rich or lean, can send false signal's, etc. 02 sensor can be bad even though you do not get the engine light.

Rayvan

My car was doing the same thing. I replaced all the fuel injectors.
Give "Fuel Injector Connection" a call and he'll set you up...

770-888-1662

http://fuelinjectorconnection.com/shop/

<3myZ

80% of the time you just need new spark plugs, I ran through az emissions really rich (failed) changed my spark plugs and wah lah, passed with flying colors.

pa_richardson

Couple of other things to check is the Fuel Regulator take the vacum pipe of it and prime the fuelpump if fuel comes out the diaphram is split.

Also check you have not got a trapped or blocked fuel return line this will raise the FP and make it run rich...an old fuel filter can cause similiar problems

Also check the Pickupcoil this can send false readings also making it run rich i had that problem..

Hope this helps...

Trust me i have been there with this running rich problem mine has run so rich it floods itself on tick over...

Viprklr

iTrader: (5)

An old/plugged fuel filter will typically cause a lean condition.

An additional check for you would be to take either an automotive stethoscope or a long screwdriver and while the engine is running, put the end on each injector and your ear to the other end of the screwdriver. Listen for the ticking of the injector opening and closing. This will tell you if you have a sticky injector. It should be a smooth consistent tick.

Hopefully your cats don't get plugged before you get the problem resolved.

Oscar

Just one thing to add. The OP mentions sometimes a smell of rotten egg. A bad O2 sensor will do that, which is why I first recommended the O2 sensor.

1tpi

Rotten egg can be bad cats

TexasSilhouette

iTrader: (4)

The smell (rotten Egg) is from the converters getting hot trying to burn the excessive fuel.

Fouled plugs are a symptom of running rich, not a cause of it. #1 most unnecessarily replaced part ever.

O2 Sensor can lead to a somewhat rich mix but what you have is way beyond somewhat.

Sticking injector is possible, not likely but possible.

Blocked/pinched return line would do it (high fuel pressure).

Fuel regulator diaphragm is a real good candidate. Look for fuel in the vacuum line.

Fuel filter, not a chance.

Noisy Pickup coil, not very likely but a slight possibility.

All fuel injectors failing together (inanimate conspiracy), extremely unlikely. One, maybe two is possible. If the case the effected cylinders will show fuel fouling on the plug. Usually injectors plug up and cause a lean condition.

Defective coolant or air temp sensor reading below zero, good choice.

I'm not a proponent of the "throw new parts at it" diagnostics. So if money is tight resist the temptation to throw new parts at it without some attempt at diagnostics.

If you are getting a bunch of extra fuel the source should be identifiable.

Is it so rich it runs rough, visible smoke from the exhaust?
Is it rich cold and hot or just one or the other?
When the scan tool was connected, did they take a look at the sensor outputs?
Are they all within range?
Was the O2 voltage pegged?
Does it do this all the time?

hitman

Thanks for the input all. The cats are new and the rotten egg smell hasnt happened often. Since I know the O2 sensor os old I will start there just because it probably needs it. At the same time I will go ahead with the spark plug changes just becuase I cant recall how many miles I have on them.

I haven't been able to get the codes scanned but the odd thing is that the codes would flash first thing in the morning, on the highway and even in traffic. Even more odd is that ever since I removed the fried A/C comressor and added the a/c delete pully, the car has not thrown any codes. The emissions do seem slighty rich, but with out a proper emissions scanner I don't know if its truly rich or just smells rich compared to other (newer) vehicles.

Is it so rich it runs rough, (no) visible smoke from the exhaust? Yes, black carbon on driveway
Is it rich cold and hot or just one or the other? Both
When the scan tool was connected, did they take a look at the sensor outputs? Was not scanned
Are they all within range? IDK
Was the O2 voltage pegged? IDK
Does it do this all the time? No

LUVN'NOS

Don't throw parts at it, i did that and got no where. I had a problem very similar, and it was a loose electrical connection at the ECM, unplug your ECM completely and check inside and plug it back in, and make sure all connections are snug, it fixed my problem that was similar to yours, but i'm no expert by any means, hope you have good luck with car!

Sam Evans

I've got an 88 formula 350 showing 538,000 miles on the odometer..had it for over 20 years…anyway the first time it ran rich was a computer failure @ 269,000 miles.. My friend had a wrecked IROC so we swapped computers and that fixed the problem. With the computer failure I'm talking about running WAY rich like 4 miles per gallon and black smoke. Years later I'm running rich again so since everything had over 350,000 miles I started replacing parts…computer…tps..coolant temp etc. But when I pulled the plenum to change fuel injectors I found the problem…a bad fuel pressure regulator….gas poured out of the plenum! If I didn't have an MSD6 with new GM platinum plugs along with a giant Jacobs ultra coil from back in the day I don't think the car would have ran. I'm getting the Holley adjustable regulator for the old tune port and I should be done for awhile…Can't believe GM wants over 800 dollars list for the Air Meter!!! I can get one wholesale but it's still $400 plus. It was a lot easier fixing the rear end that finally died..Put in used one from a 97 SS and it died after two days..ordered Eaton TrueTrac chuck and that was the end of rear end problems.

Jersey89GTA

iTrader: (1)

Put an ohm reading on the injectors. Should read .015 or above -

I had 3 out of 8 bad ones and it was rich and felt like a grizzly bear under the hood, smoke, shake.

Buy a multimeter at harbor freight for $7.99 ... go on youtube and search
Fuel injector OHM test.

Its cave man simple

I did new injectors, plugs, distrib, wires - smooth as silk now.

Sam Evans

I've already replaced the injectors because they were so old and had 350,000 on them.. But again it wasn't an injector issue..it was the fuel pressure regulator diaphragm that was allowing fuel to be dumped into the intake plentum. I don't mind replacing everything when there is so many miles on the car. Should have the holley fuel pressure regulator in by tuesday and with everything replaced this Tune Port WS6 Formula 350 will be rollin fat for another 10 years before I have to mess with it again.

Sam Evans

Installed Holley adjustable fuel pressure regulator and set pressure to 47 psi and running rich problem finally solved. The fuel pressure jumps up to 60 psi for a spilt second if you rev the engine. Put in new MSD distributor… and all GM coolant temp/ TPS sensor/ computer and 23 pound injectors along with new GM fuel pump a few months ago. New Bosch O2 sensor and new fuel filter. Before all this craziness the rear end finally died with over 500,000 miles…put in used one out of 97 SS and it when out in 2 days…Put in Eaton True Trac with BMR torque to fix that..Factory torque arm was broke and only had one hole left to attach to the rear end. Getting transmission flushed in a few days and put in some Amzoil oil and filter after the fuel regulator was installed today. Did I mention putting in new drag link and tie rods ends a few months ago? Also blocked off EGR system and put in some LS1 fans and shroud.. Air pump was removed along time ago and the catalytic convertor was removed over 20 years ago. I think I should be done for a few years !!