Biuck Lesabre 1989 backfire

GUY TREMBLAY

MEMBER
1989 BUICK LESABRE

My buick has 185000k it sart very good I the morning even by -25 celcius. But then until it reach normal running temperature it wont accelerate and it will backfire unless I go very smooth on the acelerator. Even when the the engine is warm if I try to accelerate up hill going about 40 miles per hour it will backfire trough the trottle body.I have new plugs, new wire, new pvc valve, injector cleaned, maf sensor is clean, but not checked (dont now howto check with a multimetre). Sombody told me it could be timing chain to loose and it could be check whitout dissmanteling anything?Or it could be the magnet on the tensioner inside the timing cover that could be gone. If you could help me that would be appreciated.

1 Reply

JDL

MECHANIC
16,098 POSTS

You can check codes by using a jumper wire between the A & B terminals at the datalink connector, usually along lower edge of dash. Then turn key just till the dash lites come on, no further. The mil on the dash start flashing, you count the flashes to get the codes. Your looking for two digit codes. Also, use a gage and check proper fuel pressure, also see if pressure will hold for a bit with everything off. If pressure drops like a rock, then you have a fuel pressure leak. From the sound of it, your fuel trims maybe too rich, for some reason.

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