[Frankthetank]

hey all i just bought an mq short with a 350 edelbrock in it. it runs with a holly 600 carby on gas and petrol. the exhaust systems has two dump pipes coming out just in front off the rear tires. im to scared to drive it on the road beacuse it has such an incredibly loud backfire as soon as you get off the gas. how can i stop this excess fuel waking my whole suburb???
i have noticed two spark plugs that seem so pulse in and out of the block???? what is that all about???
its only runnin the original mq 4 speed gear box what options do i have there ( i have a old gq sitting here with a new clutch and gearbox, will that fit staight in ???
my inicators dont work yet hazards doo??
hopesomeone can help cheers ALL

 

[neRok]

lots of reading for you in my website (link in sig)

i presume you have a 350 chev thats been reco with lots of edelbrock parts or something? pulsing spark plugs, that sounds suss. probably the wrong thread to the heads or they have stripped the thread or something. best pull them out and find out. they are probably causing you back firing issue too, although with a few cylinders down it wouldnt be running very good.

when i was buying spark plugs for my 305 chev, turns out there are few different types for the smallblock family. this may also be causing your problems.

you can bolt in a 5 speed MQ (MK) box, requires different driveshafts though. also need to suss out if yours was a petrol l28 or p40 or diesel sd33 originally, they have different input shaft lengths which need to be matched to work with your bellhousing/adapter system. info on my site. your GQ wont go in without a LOT of work and a new bellhousing. more info on my site.

your indicator relay is probably stuffed.

some more bad news for you, when you take it off road you will find your holley is crap and will make it flood and stall on hills. solution is run it on gas up hills, but you will loose some power. or change to straight gas and get tuned to suit (regain max power) but you will loose mileage. or get a quadrajet carb, which dont have problems with hills.

 

[MQ MAD]

Indicators not working,but hazards do ???
Replace the combo switch in your steering column
Ensure that you get the correct one for your model,as the MQ and MK are different

Edelbrock ???,Im takin it has an Edelbrock inlet manifold ???
Dump pipes are suppose to bark and carry on
Take it to an exhaust shop,get them to have a look
Could a simple fix like extending the pipes to the rear or putting a tad quieter mufflers on it

 

[Jelmer160]

I would exchange the indicator/hazard relay's first. Just to be sure it isn't a relay.

 

[MQ MAD]

Could replace the flasher units also,under the dash near the brake pedal area

 

[stag hunter]

check your timing

 

[troyboy]

lol

 

[gqpatrolz]

I also have a GQ shorty with a 350 in it.
Check exhaust manifold gasket that there are no leaks. I had the backfiring caused by the leaks in the gasket. Also check the timing. Length of the pipes may also be a problem. I run to a single large pipe out the back.
Comments on the Holly are correct. On hills the carb is no good with the floats and a loss of fuel. I run a Quadrajet which has no signs of that problem.