I got my new cam in and the car runs realy rough still. It seriously lacks power and will barely stay running. I was thinking maybe I did the valve lash wrong, are they're any other ideas as to what it may be?

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!

 

What Valve springs are you Using ?


It could be the lash, But if your using the stock springs forget about it...




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60 Ranchero - Project ( Money Hole )
85 Sport Coupe LG4 - Daily Driver

Just another Hot Rod kid, or thats what they all tell me.
Livin' the Stereotype

 

Dan, here's what I'd do...

First recheck the valve lash, and while the rocker covers are off, reverify #1 is at TDC on compression, along with the valves closed.

Next take a look at the balancer, make sure the ring is within a few degrees of "0".

Now go back and double check the plug wire routing.

Disconnect the EST line and set the base timing to 6 or 8* BTDC to start with, and see how she run's.

You mentioned in another post backfiring...was it through the intake (usually timing or reeeaally lean) or through the exhaust...afterfire.. (usually real late timing or running too rich)

Reagrding adjusting the rockers, if you're going by the book, just set'em once...it's not uncommon for the lifters to bleed down, and seem loose when you go to recheck'em.

 

Its an exhaust backfire, and I think the car is running really rich, you can smell raw fuel everytime you shut it off and also you can smell fuel while its idleing.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!

 

I forgot to mention that the springs are new. They are the TPIS springs that they suggest using with the ZZ9 cam, since my LT4 HOT Cam is very similar to the ZZ9, I got those valve springs, good to .540" lift.

 

btt

 

Honestly Dan, i think you are going to find out that you'll need a eprom to make it run like you expect. Then again, you do have a fairly good amount of mods, so you probably have alot to gain from a new eprom. As far as getting it to run decent...I'm sure you can achieve that to some extent...Send my vote for the lash... Check out this if you haven't
https://www.thirdgen.org/messgboard/...ML/001544.html
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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Problems every other day with the car (probably not a mod, but to me it sure makes a difference)

[This message has been edited by branz28 (edited February 27, 2001).]

[This message has been edited by branz28 (edited February 27, 2001).]

[This message has been edited by branz28 (edited February 27, 2001).]

 

Easiest and best way is to get a Service Manual and follow the trouble-shooting procedures.

Backfiring and rich makes me think ignition timing.

Are you getting any codes?

There are a LOT of reasons that this could be happening. The only way to sort it out if you don't have diagnostic equipment is to start checking things (process of elimination). There's no way that anyone can pin-point the cause without checking all the possiblities. That's was a shop will do and charge you plenty for doing it.

If you take your time, be patient and check all the things that I and others have posted you will find the cause sooner or later.

Do the easy stuff first:

Ignition timing (make sure the ETS wire is disconnected and the battery is disconnected for 30 seconds (min) when you're done to clear the SES code)

Spark plug condition and gap - Look very closely for any tiny hairline crack(s) that may have occurred when they were installed. While the plugs are out, do a compression check on all 8. I always pull the ECM and injector fuses, the BAT wire at the distributor to keep from loading the engine with gas. The difference between the highest and lowest reading should not be greater than 10%.

Lifter preload - One lifter that's too tight can cause a very bad idle since that valve will be held open and won't seat properly.

Plug wires - crossed or internally broken

Vacuum leak - use a vacuum gauge and the reading should remain relatively steady with no sudden drops.

Injectors - You can touch them with your hand and feel for a ticking/clicking. An ohm meter can tell if they are all within spec. A leaking injector will require a fuel pressure gauge installed on the rail.


To go beyond this, you'll need a diagnostic program like Diacom or a ScanTool.

Of course, it's possible that the cam was installed one tooth off (maybe this is where guys get the "distributor installed one tooth off" misnomer from), but that would be the last thing I investigated.

Chances are that it's something simple.

Hope this helps.

Jake

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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9