After lucas fuel treatment, my car backfires over 1000 rpm and stumbles at idle

ASSISTANCE Stock Engine-Bay Components
1

i have a 91 rs

i poured a bottle of lucas engine treatment into my gastank at a little more than 3/4 of a full tank. the car ran well for about 4 miles. while on the freeway, the car started shuddering and cutting off. i managed to pull off of the freeway. after i was in a safe area, i tried to turn the car over. it would idle for a second then cut off. it would stay alive if i gave it gas but would backfire and not go over 1200 rpm no matter how far i step on the petal. after getting home, i went ahead and filled up the entire tank, shook the car a bit and started it. same issue.

i am assuming that the problem is due to the fuel treatment and am thinking that the problem will become less severe if i let the car idle long enough and burn the excess un-dilluted gas out of the line. am i correct in assuming that the additive caused the problem? i also got a code 43 after running the car for about 30 minutes.i currently have the car idling in my back yard.

thanks in advance!

2

[QUOTE=gilcontr;1710669]i have a 91 rs

i poured a bottle of lucas engine treatment into my gastank at a little more than 3/4 of a full tank. the car ran well for about 4 miles. while on the freeway, the car started shuddering and cutting off. i managed to pull off of the freeway. after i was in a safe area, i tried to turn the car over. it would idle for a second then cut off. it would stay alive if i gave it gas but would backfire and not go over 1200 rpm no matter how far i step on the petal. after getting home, i went ahead and filled up the entire tank, shook the car a bit and started it. same issue.

i am assuming that the problem is due to the fuel treatment and am thinking that the problem will become less severe if i let the car idle long enough and burn the excess un-dilluted gas out of the line. am i correct in assuming that the additive caused the problem? i also got a code 43 after running the car for about 30 minutes.i currently have the car idling in my back yard.

thanks in advance![/QUOTE]

try draining the gas

my bro used to use that treatment every oilchange in his DA" which is mine now and its always been fine

3

i idled the car but there was no change. i am sure that the fuel consumption while in idle is nowhere near street and freeway driving. only new thing i noticed was that the car can sometimes get into a good idle when it is put into reverse. pressing the gas causes a misfire, though.

so maybe i can get away with just draining the gas from the rail and filter? the rest of the gas has been more dilluted than the gas that was sumped.

thanks for the suggestion. i’ll probably end up doing that tomorrow.

4

i checked it today and let some gas out of the line. it seems to idle ok in forward and reverse (automatic tranny) but sometimes stubles. idles ok at just over 1000 rpm. idles rough in neutral and park. will backfire and stumble after stepping on the gas. is it possible that the gas is still an issue? can it be something on the fuel rail?

5

gas shouldnt

try replaceing sparkplugs mabe there fouled out

6

i’ll try that right now!

7

well, the plugs were full of soot but the contacts were still clean. i replaced them anyhow with some ngk’s i had. same issue. i did find the problem, though. turns out that the distributor rotor came loose from the shaft. the screw that held it in place was nowhere to be seen. i took some parts off of a spare distributor i had around and fixed it. problem solved. thanks for the help! you pointed me into the right direction!:rockon: