1996 850 Base NA Severe Misfire after smooth running

zupta82 · Post by **zupta82** » 27 Feb 2019, 04:38

Sorry, by the way I did check under the distributor cap for oil and moisture, and it is bone dry. I’m thinking this has to be a main 12v battery problem or ground problem. The first time I checked for these I had continuity from the negative battery cable to back both ground straps and no resistance on my meter so I’m guessing it can’t be a short. I also checked for continuity at the positive battery cable all the way to the thick B+ cable at the alternator . Keep in mind I had the battery totally disconnected and removed fro the car when doing this

Post by **abscate** » 27 Feb 2019, 04:57

Better way to check the cable.

Install the battery. Turn on electrical loads like headlights And fan on high.

Measure voltage across battery, record

Measure voltage from starter lug and negative post. Be careful with that test probe as if it touches metal it will melt.

Record second voltage. They should be within 0.1 V

Method 2..even more exhaustive..repeat measurements while cranking

Method 3 start car , put on lots of electrical loads like full headlights, fan. Measure temperature of positive cable over 5 minutes with IR sensor

tardcart · Post by **tardcart** » 27 Feb 2019, 16:09

have you checked the timing hasn't jumped? what work were you doing before the problem started if any?

zupta82 · Post by **zupta82** » 02 Mar 2019, 13:38

I checked the the battery exactly like abscate said. I also checked the voltage during cranking and it was about 0.840v for a second then it settled to 14 volts, so i’m guessing the charging system is working and the battery cable is at about 52 degrees after 5 minutes and was not warm to the touch. I replaced the timing belt with a new full kit tensioner,water pump,pulley,etc 4 months ago. I did notice that the car wasn’t as peppy as my father 850 of the same mileage. I was thinking of testing for the catalytic convertor with the use of a vacuum gauge can someone please tell me how to proceed with this

tardcart · Post by **tardcart** » 02 Mar 2019, 16:24

If its caused by rich fuel mix (wet plugs) check fuel isn't being sucked in from the fuel pressure damper vacuum line. I think the NA's are famous for this.I dont think its the exhaust. It would run smooth and quiet at idle. also some more information on circumstance preceding problem helps such as I filled the tank with an old tank of gas that may have water in the bottom and three days later...

Post by **erikv11** » 02 Mar 2019, 17:24

zupta82 wrote: ↑02 Mar 2019, 13:38 ... I replaced the timing belt with a new full kit tensioner,water pump,pulley,etc 4 months ago. I did notice that the car wasn’t as peppy as my father 850 of the same mileage. ...

As tardcart suggested, actually check the timing. Get the front end in the air, put the crank on the mark and see where the cam sprocket marks line up. Bit of a hassle to test but it's free!

zupta82 · Post by **zupta82** » 02 Mar 2019, 18:01

If it jumped timing would the valves be bent??

Post by **wizechatmgr** » 02 Mar 2019, 18:02

zupta82 wrote: ↑02 Mar 2019, 18:01 If it jumped timing would the valves be bent??

Depends on how far it jumped. You'd know if they hit...

zupta82 · Post by **zupta82** » 02 Mar 2019, 18:08

Ok I will check!!

Thank You

zupta82 · Post by **zupta82** » 03 Mar 2019, 07:55

Do you mean the fuel pressure damper under the car next to the fuel filter

1996 850 Base NA Severe Misfire after smooth running

Re: Severe Misfire