Running Rich

[Ttype6]

When I start my car it starts right up and,very shortly after starting,it gets rich and starts chugging. There is alot of black smoke and the chugging is bad enough to make the car shake. After a short period of time the S.E.S. light comes on and sets a code 45,rich exhaust. As long as the car stays at an idle,the light stays on and it wont go into closed loop. No matter what I do,the o2 mv. stays around 940. If I turn down the fuel pressure the numbers drop into the high 800 range and the retun to 940. It goes into closed loop while driving,but will return to open loop and turn on the light when you return to an idle. It always stays around 940 and yet the crosscounts are 195. Block learn is 100. If I disconnect the mass air sensor it's still 940.

 

[ThikStik]

That happened to me and it was corroded contacts on ecm at plug ins. Could be many things...MAF, tps, stuck open injector, ecm, faulty fp reg...very rare. Probably too chronic to just be an exhaust leak.
good luck

 

[Mr. T-Type]

what are your MAF and TPS readings at idle?

 

[Ttype6]

Originally posted by Mr. T-Type
what are your MAF and TPS readings at idle?

6 gps. and .42 Volts

 

[PhilM]

I second the corroded PROM pins! I spent a week trying to find prob, guy on here gave that advice, sure enough that was the prob.

Also, the socket on the ECM could need retensioned, this would cause the same effect.

 

[ThikStik]

Philm,
Can you say, how long your rich episodes were? And did it set code? Mine was totally gremlin like. It would be running perfect and just freak out leaving engine exgtrememly rich, showing cec, and then clearing up with no stored code. Sometimes it would run fine for months before doing it again. I used around a gallon of fuel in about 1 minute once.

 

[Ttype6]

Originally posted by ThikStik
Philm,
Can you say, how long your rich episodes were? And did it set code? Mine was totally gremlin like. It would be running perfect and just freak out leaving engine exgtrememly rich, showing cec, and then clearing up with no stored code. Sometimes it would run fine for months before doing it again. I used around a gallon of fuel in about 1 minute once.

As I said in at the beginning of this thread,the o2 mv. is always around 940. As long as the motor is running,it's always around 940. S.E.S. light stays on at an idle and sets a code 45 rich exhaust. There is no period of time,while running,that it's not rich.

 

[Ttype6]

I have two E.C.M.s and two computer proms. I checked all computer wiring for opens,shorts,continuity,resistance,and propper voltage and grounds. All are ok.

 

[ThikStik]

have you pulled plugs?

 

[Ttype6]

4 different after market M.A.F. meters were all bad. Installed the Mass Air Flow Translstor and Mass Air Flow Meter from Full Throttle Speed and Style.Problem solved. If you have the factory computer and do'nt have these products,you're probably not running as good as you could.

 

[ThikStik]

Originally posted by ThikStik
That happened to me and it was corroded contacts on ecm at plug ins. Could be many things...MAF, tps, stuck open injector, ecm, faulty fp reg...very rare. Probably too chronic to just be an exhaust leak.
good luck

My first guess. Your welcome.

 

[VadersV6]

Originally posted by ThikStik
That happened to me and it was corroded contacts on ecm at plug ins. Could be many things...MAF, tps, stuck open injector, ecm, faulty fp reg...very rare. Probably too chronic to just be an exhaust leak.
good luck

Sorry to pull this old thread up, but this seems similar to a trend my car follows. Not as severe, but similar. When you say corroded contacts at the plug ins, are you referring to the contacts where the harness plugs in, or the pins in the chip/chip socket, or all of the above?
Since putting on my 50's and extender, my engine has always run very rich at idle. Ive fixed every other possible source, but Im still stuck on having to set the BLM parameter at 1 to get a reasonable idle BLM. Even then, its about 105-110 at idle. My injectors arent sticking, and my O2 sensor is good. All other sensors are working and/or adjusted.
When I took off my ls1 MAF and translator, the BLM's immediately jumped up into a better range, but still not right. When I had my trans and ls1 on, I would have to set it to 10% lean, on top of having the BLM parameter at zero, just to get it right. Cruise BLM's have always been good. Its just the idle thats an issue.

 

[ThikStik]

Sounds like your problem invovles MAF or translateer since it started then. But to answer, It is ecm plug in that got real corroded. It happened in just a few months too. That was what caused my temporary fits of severe richness that would last 45 sec or so, but a cracked Dside manifold may have been why otherwise too rich.

 

[Matt Sando]

check the egr valve

 

[VadersV6]

I took the LS1 MAF and translator off over a month ago. My EGR valve is good. The ECM plug...this is where the harness plugs in?...not the chip plug, right?

 

[ThikStik]

The male pins on computer were squalid, one was corroded in two. And of course the female ends of the harness were in need of contact cleaner. No not inside of chip carriers. Water easily targets this top ecm area.