QuestionQUESTION: A , trouble cold idle at 15 degrees or colder very rich mixture.
B. replaced o2 sensor, water temp sensor, map sensor.
C. After car runs 2-3 minutes clears up.I live in Minnesota.
ANSWER: Hi Neil,
Have you tried to get any fault codes: using the ignition key,
"On-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. The watch the check engine light that remains "on" to begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat to assure an accurate count. Then group the numbers in pairs to form the 2-digit fault code numbers.
Then write back or go to www.allpar.com/fix/codes.html for a list of codes.
Let me know and we can go from there. A very rich mixture makes me wonder if you have a leaking fuel injector. Take a look at the spray as it impinges on the throttle plate win you first start the car. See if it has drips and whether is continues to drip after it is shut off or dies.
Roland
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QUESTION: HI: I sent the injector out to be checked,cleaned.No codes show up, I have had it checked by 2-different shops, no idea,also replaced the cyl. head and all vacume hoses replaced .
ANSWER: Hi Neil,
By 'no codes' I assume nonetheless that you are getting the 55 code.
You might want to change the o-rings on your injector when you get it back if it has no problems. So again, see if the spray pattern is very fine with no dripping while running or after shut off. Also you might want to verify 12 BTDC at idle after warmed up and with coolant temp sensor unplugged. Other than those it appears you have changed/checked all item related to cold start mixture. How about the throttle body butterfly plate and side-passage: have you cleaned both sides of the plate and the side passage?
Roland
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QUESTION: HI: On the injector I replaced all the orings, took the idle control out, cleaned it also cleaned the butterfly also. Last thought maybe the injector is having problems when it cold only????
AnswerI haven't heard of temperature sensitive injector performance, Neil, but take a visual check on the spray pattern. Interestingly in the earlier 2.5 and 2.2 TBI there was a throttle body temp sensor (signal went to pin 21 of the SMEC), but that was not used on 91-94 vehicles. That is the only other mixture item, but you don't have one.
Roland
