why does my car burn fuel richly and my tactmeter fall on 0 while im driving .this causes my car to shift hard when i put it in gear and when this happens my car idles high and smoke comes out of the


Asked by Aug 15, 2013 at 12:02 AM about the 1999 Cadillac Seville STS FWD

Question type: Maintenance & Repair

i changed my egr vale and my o2 sensors plus wires and plugs but its stills burn fuel rich
and my tactmeter while im driving stucks on zero and when it starts to work again while
im driving and the car cuts off. but the engine runs great

9 Answers

okay the air intake temp sensor will play a key role in the richness of the mix...perhaps yours is faulty...also the ambient air temperature while telling you what temperature may also be linked to the data for analysis by the ECU...would start with replacing the IAT sensor~....and take it from there~

1 of 1 people found this helpful.

looks like the "air charge" temp sensor may play a key role here too~

1 of 1 people found this helpful.

the TPS is what tells the computer where your foot is....they do wear out and need replacement...if sending errant signals to the computer could very well do what you are describing....check the diagnostic trouble codes before we start throwing parts out there~

1 of 1 people found this helpful.

you can get a simple scanner to read your OBD-II codes for under twenty~

2 of 2 people found this helpful.

Have the codes read, write then down then come back here for more help with diagnosis.

1 of 1 people found this helpful.

there are no codes showing up

there would not be if it were a bad fuel pressure regulator~


OK then it's going to be more difficult to diagnose, first of all make sure the vehicles grounds are clean and tight, don't forget the sensor and ECM grounds, if no problem is found there then I suspect a fuel delivery problem, either the regulator is sticks intermittently or the ECM is changing the injector pulse width at random. If you have a code reader does it have "live data" mode? If so then you need to hook it up and drive it till it acts up and see what the sensors and outputs are reading to see where to go with further repairs.

the high idle would indicate a vacuum leak...the reduced performance could be attributed to a lack of regulation~ examine please this vacuum connection and performance of your fuel pressure regulator...looks something like this~

1 of 1 people found this helpful.

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