Hi Folks,

My 95 yukon started backfiring when I do a moderate acceleration. It's a 5.7L gas engine. It started abruptly, not something that slowly got worse.

It does not seem to do any backfiring/sputtering until it warms up. Cold seems ok.

Thinking that it was ignition related (losing spark & extra gas dumped in the TBI), I replace all 3 of the ignition related parts. Reset the timing to 3deg, and it starts fine (it always did tho).

But, it still sputters and backfires a lot. I've noticed that the tach will 'flutter' driving 'normally', but will really move around when it backfires. Almost like it's losing spark.

I've checked all of the vacuum hoses, and all are solid (replaced a couple). Also replaced the O2 sensor (it's got 245k miles on it & never replaced).

I have not replaced the fuel filter, and <really> don't want to replace the fuel pump. (just did that on my 94 yukon). ugh.

Any ideas or comments would be appreciated.

Thanks,

Tim

 

What 3 parts did you replace?

 

Hi Mr. S,

Replaced the ignition coil, pickup coil, ignition module, rotor & disty cap.

(also O2 sensor... never been replaced)

Tim

 

Hello, our 94 Chevy 1500 is doing the same. Did you ever figure out the fix for it? Thanks

 

Try this I thought it was ignition related to but it wasn't I took my tbi off and basically rebuilt it mainly I focused on the injectors replaced those and now it's got "*****" again