I don't think the CAT can break up on it's own. It can plug up if it was using leaded gas, that was an option back when unleaded first showed up.
Location: Leonardtown, MD
Posts: 9,086
My VIN: 03572
I don't think the CAT can break up on it's own. It can plug up if it was using leaded gas, that was an option back when unleaded first showed up.
Location: Northern NJ
Posts: 8,649
My VIN: 10757 1st place Concourse 1998
New Jersey used to be very tough but not on old cars anymore. Back when I used to have mine inspected they failed me once because they couldn't test the gas cap! They didn't have the proper adapter. Eventually they exempted Deloreans from that test. BTW leaded gas would contaminate the cat so it wouldn't work but did not plug it up. What plugs a cat up is too much hydrocarbons (fuel) getting into it.
David Teitelbaum
Posts: 1,322
A cat can definitely break up on its own. I had one do it. But it didn?t break up nice and clean like that. It broke out the center couple inches and clogged up my muffler to the point that the whole motor ran hot. (Again this was not on a Delorean)Originally Posted by Bitsyncmaster
Location: Leonardtown, MD
Posts: 9,086
My VIN: 03572
Good to know. I've had a couple cats start to rattle but that turned out just the large block of honeycomb lost it's seal around the metal. Otherwise it looked good inside.
Location: Renton, WA
Posts: 142
My VIN: 10332
Club(s): (PNDC)
Does the DGO cat need a heat SHield/Wrap?
Posts: 1,322
I have to admit that I ran out of gas on the highway. I was towing a helicopter with full tanks of av-gas. Av-gas is 100LL which stands for Low Lead, but in fact, it is very high in Lead. Of course, you know what I did, dumped the Av-gas in my truck. It was about 1000 miles later when I started having heat trouble. Ended up burning a valve.
Location: lincoln ca
Posts: 242
My VIN: nov 81 6900-
...
Location: lincoln ca
Posts: 242
My VIN: nov 81 6900-
failed again.. not near as bad.. not gross polluter. The cat made a huge difference. just not enough...
If its running lean im told that may be hurting my numbers
can someone clear up dwell settings? The higher the numbers mean the engine is running rich correct? if i want it to run richer the swing would be say 20-28? lean would be 12-20? is that right?
Ive adjusted timing and put in a cdc detergent thats supposed to help lower co2. Im going to drive it for a week or so and run through that tank and try again.. They didnt charge me this time because i think they felt bad.
Location: Leonardtown, MD
Posts: 9,086
My VIN: 03572
Your numbers are using dwell reading on an 8 cylinder scale. If your meter has 4 cylinder you use the book values (double those numbers you stated). You really are not changing mixture when the lambda is running closed loop. Your adjusting the center of the lambda system so it stays running closed loop under most variables. The stock narrow band O2 sensor holds the mixture at 14.7 air fuel ratio (AFR).
Now with your lambda centered (normal 40 deg dwell 4 cylinder scale), when you press the wide open throttle your dwell jumps to 53 deg and the engine runs rich because it is not running closed loop.
Location: Northern NJ
Posts: 8,649
My VIN: 10757 1st place Concourse 1998
Just turning the mixture screw doesn't always get you the results you are looking for. If you have a bad/dirty injector or a valve that needs adjustment, (or something else that needs fixing) no amount of adjustment of the mixture screw is going to do it.
David Teitelbaum
Posting Permissions
Dave M vin 03572
Reply With Quote