Xenodrgn

Ok, I'm having what I think is intake backfire, whenever it happens, it feels like the gas pedal is reaching a hard spot, and then it'll pop and the pedal will be normal... is it intake backfire? It only happens when it's cold, and not all that often, (maybe once or twice a cold start)...

Could it be caused by the fact that I'm running rich (or weak spark) or is it strickly timing?

When I adjusted the timing with a friend (valadictorian of his automotive class, works for BMW and he can't even legally drink yet...) we set it to 10*, stock spec. for my engine (says so on the sticker)... we disconnected the EST, but still got advance... we figured the EST did something else, and didn't think much of it...

Should I go out and turn the distributor clockwise a little more?

Gimme some suggestions please! :-P

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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

Xenodrgn

I should also note that I get 15 MPG... tops... with no mods... so I know it's not lean...

If the timing was way retarded (pun intended), could it cause my plugs to be fouled (soft carbony)? The loss of MPG? Make me think that the O2 is bad?

I'm anxious to hear you answers! I feel like I'm finally on to something...
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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

[This message has been edited by Xenodrgn (edited September 01, 2001).]

Xenodrgn

WTF? No answers? I figured this would be an easy one for you all... or perhaps you're all getting sick of my b*tching... :sniff: I see how it is...

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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

mystikkal_69

iTrader: (2)

Well i don't know too much about 2.8FI system or have had a similar problem. First do you get any codes? Second How long ago has a tune up been performed? plugs, rotor, cap, O2 Sensor, etc.... If no codes then look for vacuum leaks around the throttle body bellows. Since your gas mileage is suffering and if no codes present i would change the o2 sensor. worked wonders for me. I'm just trying to help here.

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88' IROC-Z, 350 TPI, 700-R4

[This message has been edited by mystikkal_69 (edited September 02, 2001).]

Xenodrgn

Tuneup was done about 4 months ago... a few thousand miles... cap, rotor, plugs, O2, intake gaskets, injectors checked, fluids, clean IAC and TB and intake, set timing to 10* (stock)(mark could be off a few degrees?)...

I'll play with the timing a little more, and worst comes to worst I'll spend my paycheck on getting the O2 cut out and a new Bosch one welded in... (threads stripped) (as well as new cap/rotor, and plugs...).

mystikkal_69

iTrader: (2)

how many miles on the engine? a far off possiblity could be a loose timing chain. have you tried running the engine with the timing a little more advanced base timing than stock...say 5*? or more. does it still backfire as bad or at all? or does it get worse? sorry to here that man. stripped threads really suck.

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88' IROC-Z, 350 TPI, 700-R4

Xenodrgn

145K... and I have a feeling they were hard miles... I don't know about the timing chain... after I get back from school tomorrow I'll play with the timing a little more... I'll let you know results.

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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg

mystikkal_69

iTrader: (2)

LOL. Hard miles. Sounds like me. Well let me what happens with the tests.

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88' IROC-Z, 350 TPI, 700-R4

Xenodrgn

All problems solved!!!

I changed out my Bosch Standard Platinums with Standard AC Delco's... gapped to .45

I bumped up the timing (advanced it... turned counter-clockwise)... pulls hard, idles smooth, no hesitation...

WOOO!!!

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1985 Camaro SC - 2.8L, auto.

http://www.xenodrgn.f2s.com/Frontright.jpg