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-   -   new cam,,, runs like crap ! (https://67-72chevytrucks.com/vboard/showthread.php?t=435110)

jitteryguy 12-11-2010 09:48 AM

new cam,,, runs like crap !
 
I plan on a road trip in the Dually when I go home on R&R, It's been need'n lifters since I bought it and I bought a cam kit right befor I left ,,, so I had a neighbor install the cam and lifter's,,,,,,,,,,,,,,,,,,,,,,,,
first thing to go wrong was the fan explode'd while he was set'n the time'n ! took out the water pump and the new radiator I had just install'd.
second thing (minor) was the vacum line on the modulator broke, it would'nt shift on the first test drive.
Now, the vacum line, fan, water pump and radiator have been replaced , it starts right up but when ya rev the engine it pops back thru the throttle body ?
the neighbor and my girlfreind have replaced the plugs, cap, rotor, plug wires, readjust'd the valves ?
she sent me a video of it be'n start'd the first time and it was run'n good till the fan explode'd. he's check'd every thing I can think of, ya'll got any idea's ?
it's a Comp Energy cam, 260 duration-440 lift.

smashingchuck 12-11-2010 09:58 AM

Re: new cam,,, runs like crap !
 
Sounds like a timing issue or maybe the cam duration is too steep for the tbi computer?

LONGHAIR 12-11-2010 10:39 AM

Re: new cam,,, runs like crap !
 
My concern is in the first statement, "It's been need'n lifters since I bought it"...
Why? and how would you know? If the lifters are "worn", this is a far bigger problem than you think.

Chuck brings up a good point, are you sure that this cam is compatible with the TBI? Wouldn't it at least need a "chip flash" to see any real gain anyway? Computers are not usually very happy about their parameters being messed-with.

jitteryguy 12-11-2010 11:36 AM

Re: new cam,,, runs like crap !
 
Quote:

Originally Posted by LONGHAIR (Post 4343687)
My concern is in the first statement, "It's been need'n lifters since I bought it"...
Why? and how would you know? If the lifters are "worn", this is a far bigger problem than you think.

Chuck brings up a good point, are you sure that this cam is compatible with the TBI? Wouldn't it at least need a "chip flash" to see any real gain anyway? Computers are not usually very happy about their parameters being messed-with.

the lifter's would bleed down over night, take a while the next day to pump back up enough to quit rattle'n, when I change'd oil they would pump up quicker than when it was get'n due the next change.

when I bought the cam , I didnt realize there may be an issue with the TBI and the cam. even now I wonder bout it, this a very mild cam, plus the fact that it ran fine the first day. how would I know for sure if they are compatible? I look'd in the newest Jeg's catolog and it dont have any foot notes or nothen bout it !
I'm hope'n for a time'n issue he has over look'd !

jitteryguy 12-11-2010 12:28 PM

Re: new cam,,, runs like crap !
 
I look'd on Compcams.com , it dont say anything about the computer or TBI issue's, it does say I cant run stock valve spring's ! I'm wonder'n now if it has broken a valve spring or somethen ?

thirdstreettito 12-11-2010 12:40 PM

Re: new cam,,, runs like crap !
 
Did you remember to do the 20 minute 2K rpm break in? Then of course replace the oil/filter. That thing will heap of trouble if it isnt broken in correctly.

spudz 12-11-2010 12:47 PM

Re: new cam,,, runs like crap !
 
With todays zinkless oil..... When breaking in a flat tappet cam...you MUST add break in oil suplement...

S10Fan 12-11-2010 12:49 PM

Re: new cam,,, runs like crap !
 
Quote:

Originally Posted by spudz (Post 4343885)
With todays zinkless oil..... When breaking in a flat tappet cam...you MUST add break in oil suplement...

Amen!

ZDDP is cheap insurance!

wyattglock 12-11-2010 02:34 PM

Re: new cam,,, runs like crap !
 
I have been thinking about swapping the cam in my 454 tbi. I called Summit and told them my setup, and with a grain of salt, they recommended a Comp Cams. Cnat remember the exact one off hand. But they did say that it would be compatible with the stock computer and engine setup. Although I think a reflash would still help it out. Give Jegs a call or email and they will help you out. Be specific on what you have done to the truck so far and they can get your best match.

jitteryguy 12-11-2010 02:44 PM

Re: new cam,,, runs like crap !
 
ya, they used the aditive and ran it for bout 30 minutes at a little above idle and changed the oil again, it ran good the first day till the fan explode'd.
I told my girlfreind to take it to buddy's shop monday if the neighbor has'nt got by then. I order'd the recomend'd valve spring's just in case, mabey it has snap one or somethen ?
suck's to be 10,000 miles away from your truck and know it's not run'n right ! I wonder if would qualify for "family emergency leave" ?

pig rig 12-11-2010 04:01 PM

Re: new cam,,, runs like crap !
 
that cam dosnt sound like its to big to screw with the vacum enough to freak the ecm out I start with checking to see if the timing is a tooth off but if it ran good while braking it in you may have broke a spring (you might get luck and spot that with valve cover off) also if you didnt add any thing to the oil for break in you might have flated a lobe
jegs/summit wont tell you if a cam is compatable with your ecm because you can tweak some stuff to make it conpatable but the cam companys will if you take with the tech. dept.


just a heads up just because it sez its works with a computer controled engine dosnt mean it works with all the other stuff you've changed that are compatibal with a comuter controled engine. when I BUILT my engine I started with the idea that if I keep every thing conpatible it will work fine! wrong! what a turd, so after a step learning curv I ended up talking with a guy that could reprogram my ecm.
when I first talked with him he put all my spects in to his computer and with a little math he said I'm leaving 150 to 200 hp on the table cause none of the sensors were in their perameters
lets just say it runs like skulleded dog now

wyattglock 12-11-2010 04:08 PM

Re: new cam,,, runs like crap !
 
Quote:

Originally Posted by jitteryguy (Post 4344030)
suck's to be 10,000 miles away from your truck and know it's not run'n right ! I wonder if would qualify for "family emergency leave" ?


The Family emergency leave idea is a good one! I dont know if I would have thought of that when I was in the Corps, but it doesnt hurt to ask. Just make sure your platoon sergeant is in a good mood when you do!
BTW, as was said before, if you are wondering about the compatability of the cam with the ecm. I should have also put that the cam companies are one of the best sources.

Thanks for serving and get home safe!

S10Fan 12-11-2010 04:25 PM

Re: new cam,,, runs like crap !
 
Several things come to mind.............Are the cam/crank marks properly aligned?......How are the lifters/rockers adjusted?.............Did the installer follow the manufactures written break-in procedure?...........If it were me, I'd have them close the hood, park the truck and eagerly await my arrival. If and that's a BIG if the cam has lost a lobe (improper break-in) that motor needs to be shut down asap! Those metal shavings that were formerly a cam lobe will end up everywhere, especially between bearing surfaces! Ask me how I know. LOL!


And a big huge thank you for your service to the good old USA!!

jitteryguy 12-31-2010 11:56 PM

Re: new cam,,, runs like crap !
 
well, they pick'd up the truck from the shop last night . runs like a champ ! turn'd out to be a ground issue, I aint clear yet if it was a bad wire or somethen left loose/off ?
I had em replace the Hydro booster, power steer'n pump and all the hose's while they had it .
wednsday my girlfreind will pick me up in Nashville with it then straight to see Trevor at Tennessee tire & wheel to pick up my 22's .

S10Fan 01-01-2011 08:08 AM

Re: new cam,,, runs like crap !
 
Quote:

Originally Posted by jitteryguy (Post 4380835)
wednsday my girlfreind will pick me up in Nashville with it then straight to see Trevor at Tennessee tire & wheel to pick up my 22's .


Coming home?

:ennyd:

68 TT 01-01-2011 11:35 AM

Re: new cam,,, runs like crap !
 
Quote:

Originally Posted by jitteryguy (Post 4380835)
well, they pick'd up the truck from the shop last night . runs like a champ ! turn'd out to be a ground issue, I aint clear yet if it was a bad wire or somethen left loose/off ?
I had em replace the Hydro booster, power steer'n pump and all the hose's while they had it .
wednsday my girlfreind will pick me up in Nashville with it then straight to see Trevor at Tennessee tire & wheel to pick up my 22's .

Welcome home.

Glad they got if figured out for you.

It will definitely need to have the chip tuned to match that cam. It is way bigger than a stock TBI cam so the factory tune is quite a bit off. It may run OK but it is going to be down on power and can get dangerously lean on the top end. With a proper tune to match the cam it will be much stronger and you won't have to worry about burning a hole in a piston when you are out having fun with it.

jitteryguy 01-01-2011 04:48 PM

Re: new cam,,, runs like crap !
 
Quote:

Originally Posted by S10Fan (Post 4381103)
Coming home?

:ennyd:

come'n home for 19 days, then back here for 8 more month's


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