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Discussion Starter #1
I have 2 1990 sevilles in excellent shape. car 1 has 81000 miles and car 2 has 111000.

Car 1 just started, with air off, while sitting at a traffic light, idling for 30 second it just stalls, no bucks or jerks sometimes I don't even notice until I try to go. It will start right up runs good at all speeds but everytime I stop for 15- 30 sec. or more it just quits. Any ideas on what to look for. I am a 74 year old retired mechanic, but this has me stumped so any help would be appreciatted.

Car 2 runs rough and on heavy acceleration I have no power and it blows 2 7.5 fusesfor the injection mounted on the let front corner of the engine dept. I replace fuses and it runs good and idles good but no power and it blows the fuses if I drive it over 30mph. runs like the catalitic converter is plugged up but it looks good, I can't figure out why it keeps blowing fuses. 2 diff. mechanics have put it on a machine that says the engine is full of carbon. I tend not to believe that because the spark plugs are so clean there is no build up[ on them. Thank you in advance for any help you can give me in directions or suggestions to go.
 

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94 Eldorado, and a 99 ETC
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3,887 Posts
ok... hmmm.... I'm pretty sure that your cars still have the OBD system. Have you gone through and checked the codes? If not you can do so by pressing and holding the OFF and warmer (red) buttons until the displays light up. When it displays "ECM?" you can simply turn the key off to exit diagnostics mode. Afterwards post them up here and someone will help you with them.

Car 1: Do you hear a "ticking" noise from the ISC (Idle Speed Control) motor when you shut the car off? Is the TB (Throttle Body) clean and gunk free?

Car 2: Generally a blown fuse means there's something wrong with the circuit (ie. it's shorted to ground). Really, the task is finding where exactly the short to ground is. You need a multimeter and a wiring diagram to help you hunt for the short.
 

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1985 Cadillac Sedan DeVille (83k miles)
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Hello Bimmer-02! I have no clue about the car 2 problem. Regarding car 1, you might want to have the TPS switch (also known as TPS sensor) replaced. This controls throttle position and will not set off a code on the OBD-I system when it fails. I replaced this on my car after over a year of guessing. You might be able to replace it yourself but the part and labor is under $200. Though this problem with car 1 could be with the mass airflow sensor, it is probably the trottle position switch/sensor. Hope this helps...
 

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Discussion Starter #4
These are the codes from car 1 with the stalling problems:
EDO49 current
EO75 history
EDO98 history
B120 history
RO34 history
RO26 history

Car2 with short reads:
EO52 history
RO34 history
552 history

Can you tell me the location of the TPS and the position of the airflow sensor?

Thank you very very much for your help. I hope someday I can help someone else.
 

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93 Sedan Deville 4.9L
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These are the codes from car 1 with the stalling problems:
EDO49 current
EO75 history
EDO98 history
B120 history
RO34 history
RO26 history

Car2 with short reads:
EO52 history
RO34 history
552 history

Can you tell me the location of the TPS and the position of the airflow sensor?

Thank you very very much for your help. I hope someday I can help someone else.
FYI for anyone who sees this, the TPS (throttle position sensor) is located on the back side of the throttle body, right near the egr vavle on a 4.9 and most likely 4.1, 4.5. It is connected with 2 screws and has 1 3 prong electric connector going into it.
 

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94 Eldorado, and a 99 ETC
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3,887 Posts
Car #1
P049 (E049)----- Air Injection Reaction (AIR) System Fault (probably what is causing the stalling issue. I don't know much about the AIR system though)
P075 (E075)----- Intermittent VSS (Vehicle Speed Sensor) Signal
P098 (E098)----- High RPM P/N to D/R Shift Under ISC
B120 ----------- Twilight Sentinel Delay Pot Circuit Problem
R026 ----------- Driver Initiator Circuit Open
R034 ----------- Dual Pole Arming Sensor Ignition Feed Open

Car #2
P052 (E052)----- PCM Memory Reset (Battery died or was unplugged)
R034 ----------- Dual Pole Arming Sensor Ignition Feed Open
B552 ----------- BCM Memory Reset Indicator (Battery died or was unplugged)

I actually think this one is probably a bad injector or two which are causing the fuses for them to blow.
 
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