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back fire into intake

3012 Views 8 Replies 4 Participants Last post by  Fordgazm1
I was leaving for work this morning and when I went to shift into second gear I heard this poping into my intake then I lost some power for a few seconds then everthing was cool. What causes this.

Just to let you know I have an 88 LX 50 5spd. the motor has 220k and has never been open.:sterb:
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if it keeps happening you may have a burned intake valve
I use to have this really bad hesation when in second gear and the pedal all the way down. It was like was lifting off the pedal then putting back down. I changed the o2 sensors and that went away but now I got that back fire.
what is the timing set at ?
Last time that I checked it was at 12 but I'm going to check tomorrow, just got me a timing light. I'm also going to do a compression test just to see how my 220k motor is doing. I'll let you know. Dose anyone know what would be good compression on a 5 liter?
What your really looking for is equal readings from all the cylinders . With that many miles I'm gonna guess that the timing chain is stretched and is causing a valve timing issue thats letting it pop through the intake . You can maybe temporarily fix the problem by dropping the timing down to 8-9 degrees , but Thats more of a band aid . do the compression test and if it comes out good then you may just want to replace the timing chain . or you may just want to rebuild it .
Im going with timing also. I did the tuneup/timing when I got mine, had it at 15 degrees running 87 (yeah i know very smart :-D) it ran great for awhile. When i was having "fun" I heard a pop and felt a quick shudder, ran same b4 as after. Backed it off and not a pop since.
Well I checked the timing yesterday and it was set at 6 btc. I set it back to 12 btc. the car runs a lot better now with better power and better acceleration through all the gears and no pops. I also just noticed that this whole time i was getting back fire through the mufflers that now have gone away with the timing change. After I finished the timing was looking around and noticed that the bolts to the starter were backing out. What causes something like that? I made sure that they are tight now but I will be keeping an eye on it.
My starter did that too . I just tightened it back up . yeah through the exhast is not enough timing . through the intake is too much .
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