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Effects of 87 octane in BPT

Posted: December 22nd, 2007, 7:09 pm
by Cpl_Bryant
Hey guys, its been a while since my last post. My brother has been putting 87 octane into my BPT MX-3 for almost a month now. Today it crapped out on him in the middle of holiday traffic. Yay. So among the other problems I discovered, he said he's been putting in the cheap gas. What are the long term effects of this? I would think he would have noticed something by now?

Posted: December 22nd, 2007, 7:54 pm
by JWMotorsports
Depends on the tuned state of the car. If it was tuned to run on 87 octane you'd be ok. If not then it could detinate under boost. If detinated lightly for a long time it will eventually wear the engine out. Things to look at are the spark plugs. Pull them out of each cylinder and look at the electrode and the insulator around it. If it is whiteish with tiny metal speckles on the electrode and insulator then it is a good possibility your engine failed from detination. Other checks you need to do are compresion test, look at the oil level (cut open oil filter with a tube cutter and inspect for metal shratenal), is the oil milky looking, & perform a leak down test. These are good indicators of the engines condition and will be the core data you'll need to analyze what happend to the engine.

So, does the engine turn over at all? If it does then is the timing belt still in one piece? Is the spark plugs sparking? Are the plugs wet if you remove them after cranking it over for a while? These are the basic things you need to check to find out if it is engine failure or maintenace failure.

Posted: December 22nd, 2007, 8:21 pm
by Cpl_Bryant
Yeah the car was running, but now only cranks. I pretty much screwed up the timing by removing the cap and rotor and all the wires from the cap. I need to reset it to Top Dead Center and reallign the rotor to cyl 1. But its night time and cold, so I had to leave it in a friggin Autozone parking lot. I hope it doen't get towed before I can work on it tomorrow. What a PITA. I don't even drive this anymore. I have a Mazdaspeed6 :D

Posted: December 22nd, 2007, 8:35 pm
by JWMotorsports
Timing and plug order makes a world of differance!

Distributor cap, reading it clock wise, should fire 1-3-4-2...if you get it out of order you'll have a nasty miss. When you set it to TDC make sure your on the end of the compression stroke which is the beginning of power stroke. With the timing cover removed the cam gear timing marks should be "I" at 12 o'clock on the intake cam, "E" at 12 o'clock on the exhaust cam, and the balancer timing mark should be at 0 degrees (TDC). Remove the spark plug and using a flash light you can visually confirm if the No. 1 piston (closest to crank snout) is a TDC. Then of coarse with the engine in this possition you simply remove the disty cap and align the rotor tip with where the cyl. no. 1 plug wire terminal will be upon reinstalling the disty cap.

Hope all turns out well for you!

Re: Effects of 87 octane in BPT

Posted: January 28th, 2008, 7:49 pm
by SpikeDerailed
Remember when putting wires on cap the dist turns counter clockwise, you probably know this but I have seen a bunch of people make this innocent mistake.