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73 & 74 Eldo Convt, '93 Fleetwood Hearse, '86 Fleetwood Limo
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5 Posts
Discussion Starter · #1 ·
I bought a 1992 Eldorado with the 4.9.
It has 50,000 miles, the car just runs beautiful. No leaks, no hiccups.

But I can't get it to pass smog. I've replaced a lot of parts and had the car serviced. It passes as high RPM, but runs a little rich at Idle. I'm very frustrated, but I don't want to give up on it.
The shop I had the work done at suggested I replace all of the injectors, but it doesn't seem to have a problem at all.

Any help and suggestions would be greatly appreciated.
 

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Administrator
2002 F55 STS, 2014 Explorer XLT, F-150s
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74,536 Posts
Have the car scanned at any parts store. Post the found OBD1 trouble codes and their definitions here.

Stop throwing parts at it.

Welcome to CF !!!
 

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Registered
73 & 74 Eldo Convt, '93 Fleetwood Hearse, '86 Fleetwood Limo
Joined
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5 Posts
Discussion Starter · #3 ·
Have the car scanned at any parts store. Post the found OBD1 trouble codes and their definitions here.

Stop throwing parts at it.

Welcome to CF !!!
It's not pulling any codes, no warnings. Nothing. The place I took it to was completely dumbfounded.

Best to cut my losses at this point?
 

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92 Fleetwood 2dr cpe - FWD, 96 Seville SLS, 02 Seville
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1,154 Posts
Post the smog test output for idle and high rpm.

Use the onboard diagnostics and post sensors, 02 voltages and fuel trims at idle and high.

Let us know which parts are replaced and released.
 

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Super Moderator
2010 DTS
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88,454 Posts
Just a shot in the dark, but check to see if the EGR tubes down in the TB bore are carboned closed.

Auto part Wheel Tire Automotive wheel system Rim
 

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Registered
92 Fleetwood 2dr cpe - FWD, 96 Seville SLS, 02 Seville
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1,154 Posts
Another shot in the dark:

Original 4.9 fuel injectors are problematic. One might be leaking causing richness at idle. At hi rpm, the fuel trim is able to compensate.
 
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