pop and crack at high rpm

[dsl kicks gas]

friend of mine wanted me to drive his truck to see why it cuts out and pops and cracks at 3500+ rpm......im thinking gov springs were not put in right.....not cranked down tight enough. because all the 4ks i have put in will turn 4300-4500 and his is lucky to hit 4k. looking for you alls input.



truck is
96 180hp
191 dvs
5x.012 injectors
16* timming
this was all done by the previous owner, im going to look at it tomorrow night, check stud protrousion(how ever you say it) and bump the timming up a little more and check to make sure the dv;s are 191's


it runs good, but acts like a truck with 3k's........could it have shimmed 3ks?

 

[BrettWINspeed]

It could be a fuel pressure problem, but more likely than that would be timing. 16* is a little low for 5x.012's, 191's and high rpm.

 

[red dodge2]

it would reset the timing to about 18* and see what that does.

 

[Scooter's Roofing]

or more

16* has never done much above 3400rpm or so for me

 

[dsl kicks gas]

i didnt get to mess with it today. ill try bumping the timming tomorrow. how much will it clear up the smoke? it smokes like a freekin train.

 

[Scooter's Roofing]

full boost/high rpm smoke? it will help...

 

[94 12valve]

or more

16* has never done much above 3400rpm or so for me

I agree my favorate is 22* runs and starts great.

Do you have head studs? or are you running the stock headbolts?

 

[dsl kicks gas]

i run 26 on my truck with studds and .020 over gasket,


his truck has stock bolts

 

[Todd W]

Mine did the same thing until i replaced the mechanical fuel pump for a fass.

 

[loganp]

First guess is timing, second guess is low fuel pressure. I guess it would be easier to change the fuel filter and stretch out the overflow valve spring first, then bump up the timing. Minimum 18*, 20* would be better if he wants to run up there all the time. Try over torquing the stock head bolts, see if you can tighten them down to 130 ft/lbs without stretching them too much.

EDIT: I DON'T SEE 60 PSI VALVE SPRINGS LISTED THERE, YOU ARE PROBABLY ALSO FLOATING VALVES!!!!

 

[Scooter's Roofing]

Mine did the same thing until i replaced the mechanical fuel pump for a fass.

it could be a fuel issue, but I've run 5x14's w/ a benched 215 pump and had no problems running up to 4,000rpm... 100% factory fuel system (had to replace the lift pump after a B20 fill up, and I replaced the OFV as preventative maint at ~180k)

 

[Todd W]

it could be a fuel issue, but I've run 5x14's w/ a benched 215 pump and had no problems running up to 4,000rpm... 100% factory fuel system (had to replace the lift pump after a B20 fill up, and I replaced the OFV as preventative maint at ~180k)

On my set up I ran 2 different mechanical fuel pumps and a new overflow valve. Same both ways, what was interesting was on the dyno it would run fine to 4000 no problem, but on the street once I got on it hard at 3400 it would sputter like crazy. I gave up and just replaced the thing with a fass and haven't had any more troubles. This was also on a benched 215 pump. I would say it is definatly chearper to try timing before purchasing a fuel system though, my timing was fine so I went the fuel route.