cat coverter

[svotta]

On my 1990 Lumina with 86k. My exhaust started to smell weird about 3 months ago. Now when my car heats up after 15 minutes or so it stalls out. I know its original. A mechanic said it could be clogged and when it heats up the back pressure chokes the engine so it dies. Another guy told me it's the fuel pump. He said fuel pump because it runs fine until it heats up and the pump is overheating. did anyone else have this happen to thm or know which one it is?

[danielsatur]

1) Any muffler shop can do a back pressure test on your catalytic converter, and a fuel pressure test can be performed on your fuel system.

How old is your fuel filter?

[svotta]

I have no clue. I doubt it's been replaced. I got the car november 2008 with 74k miles. and it now has 86 thousand. the exhaust from the cat back was new when i got it.

[danielsatur]

I heard of a dude spending $3.5K for parts + service, because of a bad fuel filter causing random misfires.

http://www.lincolnforums.com/forums/...showtopic=5675

[svotta]

really?? I'm having the car checked tomorrow anyways. the engine light does not come on and the shop already scanned the computer for codes and none came up. so it has to be something stupid and cheap. A new fuel filter is like 15 bucks and a new fuel pump is 100 and a new cat converter is 130. so if it's anyone of those its not too bad. And if the shop says its a fuel pump i'm bring ing somehwre else to see if they say the same thing.

[danielsatur]

A plugged catalytic converter will not throw a code, it usually chokes the enigne out, but a blown cat will throw a PO420 or P0430 type code.

1) The muffler shop can do a catalytic converter back pressure cheap, the fuel filter needs tobe done anyways!

[svotta]

the entire fuel system needs to be done. The tank has rust and the lines are rotted but no leaks at all. When i first start the car it runs awesome then after 10-20 minutes it starts to sound like its choking. then it will die then restart then a minute or so later die again. Then when it cools down its fine for another 10-20 minutes. The exhaust is very quiet. It could be clogged from being 20 years old right?

[daffysmiles]

when vmy catalytic converter went bad in my 93 euro it was easy to spot. i pulled into driveway looked under my car and it was glowing red hot.

[kevinb70]

you absolutely have to test items in suspect, rather than replace without a true detection of a part failure. whoever said it was fuel pump without a pressure test is gambling with your money. even OBD-II codes can be misleading.

your issue sounds similiar to one post here recently. i think max mentioned possibly faulty ignition module or ignition coil can cause that condition (runs when engine cold, wont run with engine hot) however i cannot confirm that as my 98 w/184k has original ignition coils and ignition module.

which could be tested with spark tester connected to an old (working) plug wire, pop wire off at the ignition coil, plug old plug wire onto coil (easier to reach than plug boots), ground the spark tester.

if you have a timing light, you can plug the timing light to each of your 6 plug wires... a good spark will strobe the timing light (course you can't set timing with it!)