# Suggestions for best coil, plugs and wires for 87 Dakota 3.9L **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [April 10, 2024, 4:27am UTC](https://community.cartalk.com/t/suggestions-for-best-coil-plugs-and-wires-for-87-dakota-3-9l/194696 "2024-04-10T04:27:48Z")\ **Posts on this page:** 1\ **Showing post:** 14
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [April 10, 2024, 10:27pm UTC](https://community.cartalk.com/t/suggestions-for-best-coil-plugs-and-wires-for-87-dakota-3-9l/194696/14 "2024-04-10T22:27:14Z")
Calif smog testing … been there, done that! … lol … What part(s) of the test are the most burdemsome to pass for you? HC? NO? In any event, suggest to take a look at this thread for a 92 Corolla with HC readings near the limit. The 92 Corolla is fuel injected, so doesn’t exactly apply to your Dakota, but it does have electronic ignition w/distributor so probably still worthwhile. > [@92 Corolla High HC Emissions](https://community.cartalk.com/t/92-corolla-high-hc-emissions/84622): > > Every two years here in Calif I have to do an emissions test on my 92 Corolla (4AFE engine). Every year I just barely pass the HC limit. I just had this test done last week. So I should say “Every year I barely pass, until now”. Here’s the emissions data showing I failed: HC’s at 15 mph measures 140, max allowed is 130. FAILED. HC’s at 25 mph easily passes with 67 measured, max allowed 105. PASSED. CO and NO easily pass at both speeds. PASSED. %CO2 =15, %O2 = 0.1 to 0.2 (Not part … Quick summary: I discovered these definitely helped, roughly in this order - Retard ignition timing 2 degrees from spec - Fresh engine oil - NGK V-Power spark plugs (reduces HC) - Remove carbon gunk from distributor cap terminals and ignition rotor. - Or even better, install a new cap and rotor & new wires. - Try to clear as much gasoline from the evap canister as possible. Done by doing a lot of driving. Definitely do not fill the gas tank just prior to the test. You don’t want extra gas flowing into the engine from the canister during the test. - I’ve used a “guaranteed to pass” type of gasoline additive sometimes, and sometimes not, just prior to taking the test. Not clear if it had any effect. My biggest and most surprising finding was that a slightly clogged air filter helped reduce HC levels more than any of the items above. I think that’s b/c of the specific configuration of a 92 Corolla though, which uses the “speed-density” method to set the air/fuel mixture. So a slightly clogged air filter probably wouldn’t work – and would probably make matter worse – with a carbureted vehicle. BTW, I think cars 25 years and older shouldn’t require tailpipe emissions testing, except perhaps just visual inspection to make sure all the emissions parts remain installed. Here’s to hoping our Calif politicos finally see the light on this issue. They’re up for re-election this year, so now is a good time to lobby them. . --- _[View the full topic](https://community.cartalk.com/t/suggestions-for-best-coil-plugs-and-wires-for-87-dakota-3-9l/194696)._