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I am willing to try anything at this point. Bought the car not running figuring I could get it going but have had no such luck.
Yellow 1986 Oldsmobile Ninety Eight Regency 3.8L V6 Auto 88,000 Miles
Cranks over but will not start
What I have found
-Has no spark
-Has no injector pulse
What I have replaced
-Computer
-Ignition Control Module
-Coils
-Crank Sensor
-Cam Sensor
What I diagnosed
-Injectors all have 7 ohms resistance
-Harmonic balencer key way is good and tone ring looks good
-Ohmed out wires going to both cam and crank
I have a running BLUE 1986 Oldsmobile Ninety Eight Regency that I bought in great shape that is now having backfiring issues when you snap the throttle and randomly loses spark and wont start. I bought the no start YELLOW Regency and swapped cam sensor, crank sensor, and ICM from both and the BLUE to the YELLOW and the BLUE one is still acting the same and the YELLOW one still has no spark. Im lost and im up for opinions. Im trying to get the YELLOW one running as the intake box is broken im guessing due to back firing just like the BLUE one is doing so in hopes of getting the YELLOW one to start and finding the problem im guessing it has the same issue the BLUE on has only its completely failed.
This video includes both cars for a reference of what they are.
How is the wiring on the main culprits like crank sensor and cam sensor (like not just at the sensor and plug, but the whole way to wherever it goes) ?
I ohmed out the wires to the cam and crank sensor to the ICM and they had low resistance with no open circuits. I also pulled the wire loom back all the way and visual inspected the wires and they all look fine.
As far as codes the battery has been disconnected for several years so any codes up to the point that I owned it are well gone. The service engine light comes on when its keyed on so I know the computer is working. How will I know if it has codes and how do I get them?
It will flash an [I am a happy computer] code first then will list out any other codes it has stored. all codes are 2-digit and have pauses between each code. When it returns to [I am happy] it has completed and started over again. It will do this as long as your paperclip is there and it has power. The [I am happy] is 12 , so flash pause flash flash pauuuussssse next code.
Well I found the problem. The cam sensor magnet was broken off. Not sure what happened first the bolt loosened up and the magnet took out the chain guide or the chain guide broke and hit the magnet. All I know is I have a mess and have to decide if its fixable.
Question is do I need
-Cam sprocket due to plastic chipped off all around it
-What is the disk on the front of the cam sprocket do and do I need a new one?
-Anything else other than timing chain guide kit, and a few gaskets.
Well I just ordered and will be here tomorrow a timing chain kit with both sprockets, Timing chain tensioner, and a timing cover gasket set. A whopping $55. I already had the magnet as I was doing an amazon order and seen it was only $5 so I bought it without knowing if it was even bad. Should have the car up and going for $60.
Are the cam and crank still in time, i.e. the timing marks like up? These are supposed to be interference engines, and GM'* choice to used the V8'* style, pot metal and nylon camshaft timing gear condemned most of them to an early death in a rough, 90 degree V6.
The other bad news is most of the nylon heads right to the oil pump pick up. The good news is the oil pan is probably shockingly easy to remove. It is in the A-body, which has a very similar engine cradle, but slight motor mount interference. I didn't even remove the starter! The other good news is the timing cover will be much easier to install with the oil pan off.
This is the odd little brother of the 3.8, the 3300 (a lot of improvements,1992 model).
That is the 'cam button' on the end of your camshaft gear. It is one way of control camshaft end play.
Well its been a busy day but I had time to do a compression check. Anyone care to share what they should be and were the timing marks are one these things.
I can't caution strongly enough that it is very important to keep ANY debris from the pressure and suction ports from the oil pump through the front of the block. Very easy to kill a Buick or old Cadillac engine with timing cover gasket debris. Small debris in the oil galley and can block lubrication that you won't find until shortly after the engine is running.
The oil galley ports are on the bottom right of the cover in the picture below;
The 3300 and 3800 of this era had the same timing cover, but the 3300 is not drilled out for the camshaft position sensor, as it was only a MPFI engine rather than SFI like the 3800.
I can't caution strongly enough that it is very important to keep ANY debris from the pressure and suction ports from the oil pump through the front of the block. Very easy to kill a Buick or old Cadillac engine with timing cover gasket debris. Small debris in the oil galley and can block lubrication that you won't find until shortly after the engine is running.
The oil galley ports are on the bottom right of the cover in the picture below;
The 3300 and 3800 of this era had the same timing cover, but the 3300 is not drilled out for the camshaft position sensor, as it was only a MPFI engine rather than SFI like the 3800.
I will make sure to clean them out good thanks. I took the cover off and im taking it into work for a good cleaning.
10-04-2018, 09:49 PM
1986 Oldsmobile Ninety Eight Regency No Start
