I'm looking at buying this camaro, it's an 88 with a 355, well, it keeps popping through the exhaust. He's gone through 2 distributors, it's got a 750 holley double pumper, street dominator intake, headers, flowmaster, it's got about 100 miles on it. And he can't figure out why it does it and neither can i. The distributor has one of those spring kits in it. It used to have a gear drive but he swapped it out for a good chain. It's got the stock heads though. Could he have done something to them? warped them or done something to one of the valves. Could it be bad plugs? I really want this car but I don't want it if i can't figure out what's wrong with it. Thanks for any help that you can give me.

Also when I asked him what cam was in it, all he know's is that it's 3 over stock. could someone point me in a direction to find the specs on it, or am i just gonna have to put a new one in to know exactly what it is. Also, it has posi, but i dont' know about gears, could someone give me a rough extimate on what the gears might be for an 88 z28, 700r4. Thanks again.

Wally

 

Are there any exhaust leaks, the pressure loss could cause a backfire. Also check to make sure the choke is adjusted properly. Bad plug wires could also cause it. I would take them all off one at a time. This happened to me twice as they laid on the headers and completely cracked through. But this also cause a bad miss and acceleration problems. I'm not sure what gears you have in it though. An easy way to check if the car can run is get up to 70 mph in D not OD and whatever you are taching say like 2730rpms then you have 2:73 gears and so on. The only way I can help you with the cam is to know what the specs on the original cam and look in summit at there cams, then just go down the list 3 part #'s and that should be the specs on it.

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"Rice burners are like tampons...Every pu$$y has to have one"
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

 

if i understand what you're trying to say correctly i believe you have excessive fuel entering the exhaust and is being burned there. check the float level, the jets, the timing and make sure the basic tune up is correct and in good condition.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

my car pops through the exhaust when I'm coasting in a lower gear/higher RPMs(only when slowing down though). My friend's 93 formula does the same, but only after he gutted the cat. I think flowmasters pop like this also( I think my 85 with an 80 series did)

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'86 IROC 5-speed
305 LG4
edelbrock performer rpm intake
edelbrock 600 cfm carb
msd pro billet hei distributer
'95 3.23 rearend
hotchkis rear suspension
PST front polygraphite suspension
"speed kills. buy a f@&d, live forever."

[This message has been edited by iroc5speed (edited October 07, 2001).]

 

Some mufflers I do believe make a crackle pop kind of sound, but if the exhaust is popping as in a slight backfire then that's not normal.

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"Rice burners are like tampons...Every pu$$y has to have one"
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

 

It's got hooker LT's, and flowmaster. He's got a 650 holley that we could throw on there too. But it did it with the 650, the 750 and TBI. He's put two different distributors in, the wires are fine. The plugs i'm going to change, and i'm going to run a compression check to see if it's wrong in the heads or something. But other than that i don't know where to go from there. And it's not the muffler cause it doesn't sound like that. Vacuum leak? Could that spring kit be advancing it too far? Vacuum advance not right? Could the old computer from the TBI be doing something? Thanks again.

Wally

 

definitely check ur valves and see if u have a stuck valve or the timing might still be off. also try goin a little leaner on the gas. i had excessive fuel flow into mine when i bolted on the holley 750and it ran like crap so check the mixture and make it a tad bit leaner.

 

definitely check ur valves and see if u have a stuck valve or the timing might still be off. also try goin a little leaner on the gas. i had excessive fuel flow into mine when i bolted on the holley 750and it ran like crap so check the mixture and make it a tad bit leaner.

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86 berlinetta
350cui w/.30 over
.526 hilift cam
hooker supercomps
3" duals
edelbrock streetmaster
holley 750 dp
bad asshauler

 

Well I would:

1. Check the timing, also see if he can tell ya if it did it before he swaped the tioming gears out.. it the cam was moved and wasn't degreed correctly when put back in that would cause some issuses...

2. Breaking dist. is not good.... That could be just a cheapo part or the gears ont he cam being messed up from a forced installation or just someone not knowing what they are doing replacing the springs

As far as the popping goes is it a bang or a pop cause depending ont he exhuast it could just be normal back pressure noise.. If I were you I would wait to see how the engine breaks in a little more.. cause 100 miles is kinda fresh, I would wiat at least 500 miles that is a decent breakin time... that way you will get less suprises

Also try jetting the carb down 750 is kinda big for a fresh stock headed and vavled engine...


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PMD Power
ICQ 70557275
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79 T/A 455 WS6
91 Firebird LO3

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