q2blaster

what would cause my car to start running rich all the time.

To give you a brief history, I had my good chip sent off to my tuner and while it was gone I had a junk chip in the car so I could move it around,car seemed to run fine but the check engine light was flashing rapidly, I decided to chance it and drive it to work, made it about half way when it quit. It wouldnt idle and i just made it home. Cheched all plugs and they were black. I got my chip back from my tuner and installed it and replaced all the plugs, still running very rich, where should i start looking? Is it the maf? Car was running fine except was a little rich wot, which is why after a coiuple dyno runs I sent the paperwork and my chip back to get changed. Dont think its the tuning.


[SPOILER]My car is an 85 L98,4+3, 262 extreme energy comp cam 114lsa, bowtie heads, 24lb svo injectors, 35lbs fuel pressure.

q2blaster

[QUOTE=q2blaster]what would cause my car to start running rich all the time.

To give you a brief history, I had my good chip sent off to my tuner and while it was gone I had a junk chip in the car so I could move it around,car seemed to run fine but the check engine light was flashing rapidly, I decided to chance it and drive it to work, made it about half way when it quit. It wouldnt idle and i just made it home. Cheched all plugs and they were black. I got my chip back from my tuner and installed it and replaced all the plugs, still running very rich, where should i start looking? Is it the maf? Car was running fine except was a little rich wot, which is why after a coiuple dyno runs I sent the paperwork and my chip back to get changed. Dont think its the tuning.


My car is an 85 L98,4+3, 262 extreme energy comp cam 114lsa, bowtie heads, 24lb svo injectors, 35lbs fuel pressure. :confused

byebyeL98

Did the check engine light continue to flash once you put the good tuned chip back? Any codes?

I would start with the O2 sensor. If you have a scanner, check to see if it is going into closed loop mode. You can also verify O2 cross counts. The overly rich condition (from the old chip) might have really fouled up your O2 sensor.

q2blaster

the engine light doesnt flash anymore with my good chip, no codes flashed when i jumpered it, I dont have a scanner, I guess I will have to get one.

byebyeL98

Even something as simple as an Auto X-Ray Scanner will be able to provide you with a lot of good info (BLM / INT numbers, O2 cross counts, open/closed loop mode, knock counts, temperature the ECM is seeing, timing, etc.). I think it would really help us pin point why the engine is running so rich now.

0ski_dwn_it

Is your o2 sensor working? This would have the car to run ReAL rich

CFI-EFI

When the check engine light came on, flashing or not, a code was set. Unless you have cleared the codes, they are still "set" in the ECM. Check them and follow your factory service manual to trouble shoot them.

RACE ON!!!

SunCr

Agree with everything posted. Spend a 100 Bucks or so on an inexpensive scanner and if you have the budget, the Shop Manual can be invaluable though to understand how it works, pick up Ben Watson's Chevy Fuel Injection at Borders. A dead 02 sensor, however, isn't going to make it run so rich as to foul the plugs or produce black smoke. Assuming the fuel pressure is correct for your injectors (in fact it looks a little low), I'd suspect that the ECM thinks it's lean so it's adding fuel and that flashing Check Engine Light may be a code 44. If so, it may have a vacuum or exhaust leak or the air pump circuit might be faulty or the fuel pressure is too low. You might also have a valve train problem depending on how you adjusted the valves or you may need a better tune for the cam (though I'd think that the stock ECM wouldn't have a problem with it).

q2blaster

Replaced o2 sensor, bought cable, car wont communicate with laptop, super rich, I think the ecm is junk, what do you think,

P.S.
I would like to drive this car a little before the snow comes,im trying not to whine but running out of patience and finances for the car for the year. Any suggestions would be very appreciated.

rodj

How is your plumbing ahead of the TB?
I had this same problem several days ago ('87 L98 ), developed a air leak around homemade smoothbore adapter between TB and MAF.Was bleeding air directly into TB .
Clouds of petrol smoke .Average fuel at cruise would go from 12 suddenly to 45-60 (metric).Would cough and then die .Had to clear ECM to get it to start , similar symptoms to yours. Also thought it was O2 sensor.Finaly got home , checked codes.
Was throwing Code 33.
Put old flex on , checked all connections , problem fixed.Worth a look.

byebyeL98

You definitely need to see what the ECM is seeing, or reading. From what you've posted, I don't THINK there is anything wrong with your ECM. Replacing the O2 sensor wouldn't do anything if the car isn't going into closed loop mode.

I would highly recommend posting in the scan and tune section in order to get the scanning/communicating issue resolved. There is a LOT of knowledge over there. List exactly what type of laptop you have, the cable you bought, and the software you are using. Once you get a real time scan, we can definitely help pin point the problem.

Hang in there!

Morley

Check your regulator for fuel insde of it (pull the vacuum line). Next do the leak down test on the fuel system, might be bad injector (s).

q2blaster@work

Closed loop flag is checked, rich flag goes on and off. What #'s do you guys want to see. Never datalogged before, just tell me what and ill post it