Question
emission 001
QUESTION: Roland,
Having trouble passing emissions test with a 1994 plymouth Sundance 2.2L engine:Compression test:1-117,2-116 ,3-112,4-107
1st test: --HC standard-.80measured 1.09failed,
CO standard15.00-measured6.06passed
NO standard 2.50--measured 2.62 failed
Changed air filter--washed throttle body with carb cleaner while running engine new dist cap,wires & plugs & rotor.
2nd test HC measured 1.05 failed
CO measured 6.30 passed
NO measured 2.14 passed.
New thermostat & new temp sensors.
3rd test: HC measured.90failed
CO measured 4.2 passed
No measured 1.93 passed.
Rolans--Not sure what to do next --I sent you the graph of the test and It appears to me that it is failing @ idle & when the throttle is backed off. I do notice some very fine fuel droplets kinda bouncing around the butterfly valve on the throttle body? leaky injector--mabe a oxygen sensor thats a little off? I have NO fault codes.
I will appericate all suggestions,thanks,
Den
ANSWER: On the fault codes, I assume that you do get the 55. Correct?
I would look at three possibilities:
The injector: while exactly what constitutes very fine fuel droplets is inexact, also I would watch while a helper turns off the engine to see if the drops continue after cut off, which it should not do. The spray should be very fine at idle, but I don't know if bouncing droplets is a sufficiently bad symptom. Driping would be. Unfortunately the tbi injector lists at the dealer for about $150, but I had to replace mine once so far in my '89 2.5L because I saw driping quite obviously.
The ignition timing might be off: Warm the engine, then disconnect the coolant temp sensor on the side of the thermostat housing (the fan will come on) then check the timing to see if it is 12 BTDC.
The catalytic converter: could be worn out but that would be the last resort.
I hope that you can pass on the next try. Let me know of your progress.
Roland
---------- FOLLOW-UP ----------
QUESTION: Roland,
I just checked the codes & come up with 12,22, 33 & 55
I don't have air cond so 33 is out It seems I always get 12 battery feed to Smec but 22 coolant sensor--will have to check this further--NOT getting check engine light.
Roland,
I've read a number of your helpful answers to asked questions and want to say THANK YOU--It's very kind of you to help people--I wont be able to check this out for a couple days but will keep you informed.
Thanks Again,
Den
AnswerHi Den,
Yes, the coolant temp sensor, if reading lower than actual temp will certainly cause a too rich mixture. That will probably solve your problem. As you probably know, it should read 700-1000 ohms when the engine is at operating temperature. Anything significantly higher than that would raise the HC.
Roland
