Help Needed: First High Throttle Shift Misfire, Code 36, Low Oil Level Light Flashes - SES

8
0
1
Buick Ownership
'95 Roadmaster Sedan
Thread starter #21
In one post, you and some others mentioned the "Oil Level Sensor" and other post, the "Oil Pressure Sensor"! WHICH ONE IS IT? Neither one would cause random misfire! You apparently have an electrical issue somewhere in the positive or ground system feeding the ignition system.
Someone did mess up wiring so is most likely not totally related to the sensor however data is showing a voltage spike from that circuit, hence the light and the misfire. Seems to think the pressure is low enough to cut fuel.

Its complicated. But more tests to come. :)
 

Zeroboostbuick

Active member
354
75
28
Location
S.W. Ontario Canada
Buick Ownership
2018 Regal Sportback - 2010 Yamaha R6 (track bike) Past cars: 92 LeSabre, 98 Regal, 02 GrandPrixGT
#22
Friends parents had a Jag that was acting up electrically and other stuff... Ended up being the ECM electrical connection was corroded.

Also... I'm not sure how the fuel pump works on the RoadMaster... but most fuel pumps have low and high speed, and sounds like it might be the high speed portion of the fuel pump that might be acting up ???

Again, I have no clue about the optispark, but is there a specific way of installing it ? maybe something small was missed ???
 

glennb49

Buick Newbie
12
0
1
Location
Beaver Dam Wi.
Buick Ownership
53 Skylrk, 94 Roadmaster wagon
#23
Rob replaced the knock module on the body computer under the air cleaner, with the one off his Fleetwood. It started and did not stall out or shut off air when he power braked it up to 3K!! took it for a ride but then ran really rich once oxygen synsers kicked in. Rob put my knock module back in and it was back to the same symtoms! Could this be the fix? sure seems to be! Rob said to get a knock module the same part number as mine, top row is 16188309, bottom row is I083351. the 3351 is the number that is different on them. Do I start looking in the salvage yards at every LT1 or does only a 94 Roadmaster work. On way home from picking up car from Robs if I just drove it normaly it did not cut out, air stayed on! just when I trumped on it as though to pass it cut out! so its behaving better what with all that Rob did. Now will it pull my camper with out cutting out and shutting off air? Im on quest to find a part no. 3351 knock module!!
 
4
0
1
#24
I'm having the same problem on my 95 rdmst changed plug opti and water pump. The code from the climate control is say 26 which is right bank o2 sensor. Would the o2 be the problem
______________________________
 

Dirtybob

Junior Member
51
8
8
Buick Ownership
95 RMS
#25
It would definitely replace the O2 sensors, but I've never had a bad O2 cause a miss fire before.

I recently replaced my opti with one from this seller on ebay Optispark reconditioning service with data that it works | eBay
but I didn't have an OEM opti to send in for rebuild so I got one of his 'other' optis for sale.

After installing I noticed the car was still running a bit off and was logging KR all over the place. Did a little research and it seems that not all optis are correctly indexed (i.e. when replacing the bearing). Fabbed up a timing pointer with some junk I had laying around the shop and marked TDC #1 on the balancer using a piston stop. My timing light was showing about 4 degrees advanced from what the logger (pcm) was commanding.
It would've been better if I had done this before replacment so I had a basis for comparison (no idea if the old opti was also indexed wrong). After adjusting the timing tables the car is back to it's old self.
Not saying this is your problem but this is something I think more people need to be aware of, could save you many headaches. If your new opti is indexed too far retarded on the timing your car will run like poop...

CIMG2020.JPG
 

Zeroboostbuick

Active member
354
75
28
Location
S.W. Ontario Canada
Buick Ownership
2018 Regal Sportback - 2010 Yamaha R6 (track bike) Past cars: 92 LeSabre, 98 Regal, 02 GrandPrixGT
#26
It would definitely replace the O2 sensors, but I've never had a bad O2 cause a miss fire before.

I recently replaced my opti with one from this seller on ebay Optispark reconditioning service with data that it works | eBay
but I didn't have an OEM opti to send in for rebuild so I got one of his 'other' optis for sale.

After installing I noticed the car was still running a bit off and was logging KR all over the place. Did a little research and it seems that not all optis are correctly indexed (i.e. when replacing the bearing). Fabbed up a timing pointer with some junk I had laying around the shop and marked TDC #1 on the balancer using a piston stop. My timing light was showing about 4 degrees advanced from what the logger (pcm) was commanding.
It would've been better if I had done this before replacment so I had a basis for comparison (no idea if the old opti was also indexed wrong). After adjusting the timing tables the car is back to it's old self.
Not saying this is your problem but this is something I think more people need to be aware of, could save you many headaches. If your new opti is indexed too far retarded on the timing your car will run like poop...

View attachment 11932
Great response about indexing the optispark. As this is probably what most folk do wrong and can't figure out what is wrong after replacing the optispark.
 

glennb49

Buick Newbie
12
0
1
Location
Beaver Dam Wi.
Buick Ownership
53 Skylrk, 94 Roadmaster wagon
#27
after pulling my camper on a test run the car did pretty well and did not cut out and air stayed on until I tromped on it, then misfired and air shut off till next key cycle! When I got home backing trailer up driveway it starting surging again. Got trailer parked and unhooked, when started wagon up it would not excelerate and would kill. Let cool and tried again, now it starts and kills, Let cool more, now it wont even start!! Is my new fuel pump taking a crap? Rob has given up! Have new guy Mike bringing fuel pressure gauge over Sunday to see how fuel pressure is! Im getting so frustrated with my wagon!
 

glennb49

Buick Newbie
12
0
1
Location
Beaver Dam Wi.
Buick Ownership
53 Skylrk, 94 Roadmaster wagon
#28
went out and pulled fuse on fuel pump relay yesterday morning, it was good. turned on ignition and heard fuel pump running. Cranked engine and it fired right up. let run for several minutes and shut off. restarted and now wont excelerate again! Mike will hopefully come today and well check fuel pressure upon cranking and running and when it wont excelerate!
______________________________
 

glennb49

Buick Newbie
12
0
1
Location
Beaver Dam Wi.
Buick Ownership
53 Skylrk, 94 Roadmaster wagon
#29
We found no fuel pressure when cranking , unhooked fuel return line and there was no gas present when cranking so pressure regulator is good. Looks like have to drop tank again and see what up with fuel pump! Can hear pump running but no pressure, collapsed hose , bad pump?
 

glennb49

Buick Newbie
12
0
1
Location
Beaver Dam Wi.
Buick Ownership
53 Skylrk, 94 Roadmaster wagon
#31
waiting on Mike to drop tank and see whats up! Looks like it will be next week what with Iola starting Thursday 12. Ill have my 53 Skylark in blue ribbon! Wish the wagon was as simple as the nail head!
 
354
75
28
Location
S.W. Ontario Canada
Buick Ownership
2018 Regal Sportback - 2010 Yamaha R6 (track bike) Past cars: 92 LeSabre, 98 Regal, 02 GrandPrixGT
#32
Kinda really sucks if you have to drop the tank to access the fuel pump.

Wish you had a access panel in the floor like most sedans and SUV's nowadays.
______________________________
 
4
0
1
#33
So I replaced both of the lower o2 sensors( broke 3 extensions and 1 ratchet) seems to have fixed the miss fire but nothing changed with the "coughing" and throwing a low oil light then "ses"light could it be a vacuum leak some where?
 
12
0
1
Location
Beaver Dam Wi.
Buick Ownership
53 Skylrk, 94 Roadmaster wagon
#34
it was out of gas!! my new sending unit was sticking and showing 1/2 tank when it was empty! That Knock module I installed seems to make a difference to the better. Yesterday while driving on freeway it started to stumble when I used turn signals just like yours Skymonkey! not every time though. this car just continues to get more frustrating! Ill have to get an ignition switch?
 
Your email address will not be publicly visible. We will only use it to contact you to confirm your post.
Top