Okay, This isnt Very impressive.. a L05 with the Ultimate TBI Mods.. 1 5/8 Headers with 3" Crossover and 3'' to the rear. Everything Listed is For a 350. TPI Fuel pump, Fuel Injectors(TBI), Caprice ECM with a Custom Chip from TBIchips.com, I also Lifted the Injectors 1/2 Inch. I was told the AFR wasnt quite Right. Once the Engine hit 4500rpm It was spitting/coughing/choking... and it all went down from there. we made two Runs... Kinda sketchy. So I drove home, and went over what ive done. and realized I didnt Change the ESC Which was the original 305 ESC, So I went around Looking for one. and ended up buying a New 350 ESC. It revs up and shifts at 5500 Rpm. But Looses quite a bit of power at about 5000rpm.. I think the ****193 Heads may be the culprit. However, The ESC doesnt Change anything for the AFR does it? So How can I get the AFR where I want it?

 

Invest in Prom Tuning equipment and learn how to make DIY chips.

 

Oh no... Thats like Level 4. Im on level one.

 

Dont expect your stock cammed engine to make any power above 4500rpm. until you do a cam change and some other type of tuning Intake etc. Thats really not bad for a basically stock engine,

 

Okay, Say I Get a LT1 Cam in there. I think I have a Roller cam. Not sure. What is that cam going to do for me?

What about a LT4 Cam? I dont want to go overboard on the cam.

 

I would also uprgrade your manifold if you havent done so already?? as well as an ignition upgrade and a good exhaust system. If you do all that plus prom tuning you would probably pick up close to 40hp or more at the crank. That could be a gain of 25 or more at the wheels. This is just a questamate though.

 

Already got the Prom Tuned for what ive got, and the exhaust has been upgraded. Intake is Stock Cast aluminum.

Would Not having the IAT hooked up Cause an issue?

 

The engine is also rich, so taking some fuel out may add about 10 HP. It looks like your making around 200 or so now. Id say dump the heads and cam, they're not helping. In stock form, the swirl ports are at the bottom of the barrel. The flow even less than standard smog heads.

 

Definitely start tuning as soon as possible!

 

Dump the cam for sure, the swirls are not all that bad. The intake flow is less than some of the smog era heads, but they have smaller 64 cc chambers and the swirl speeds the burn. The exhaust ports also flow very well for a stock casting. These extra 3 things mean that I have seen 300 FWHP on several stock swirly casting 305/350 engines and 225ish HP on a 4.3. The cam and the tuning are the real offenders.

 

What Would you do if you had a Engine that would Start Pinging and sputtering at 4500Rpm? I tried timing... Still pings and sputters. gets worse in when trying to advance, and the idle gets rough when heading toward retarding and the engine is sluggish. Fuel, Ive filled up with Shell V-power. messed with the timing. Still pinging/sputtering. So I Bought Lucas. Gave It a Good strong dose. drove it 50 miles. nothings changed. Messed with the timing.. still getting that 4500rpm pinging/sputtering.

 

I would get into prom tuning and fix the problem. Seriously your giving up an untold amount of power from that canned tune. You can see that the AFR isn't even in the ball park and your pinging shows the timing is way off. You would probably make more power with the stock chip.

Also I wouldn't even dream about going any further with mods untill you can tune what you got.

 

You know what BMmonteSS, I dont know your real name.. I have a feeling its Mike... or something.. lol Anyway. I did 5 Hours of Searching Computers and Chips and what you guys have found to work best. well I came across my own thread.
https://www.thirdgen.org/forums/dfi-...ome-stuff.html

If you Read what RBob stated at the end there.

"I don't believe the '89 Caprice had VATs, but you may want to try the ECM before going to the track. Just in case it does. If it does the injectors won't fire.

You should be able to run the 350 injectors with the LO3 ECM. The BPC is a ratio of displacement to injector flow. The displacment has been increased, putting in the larger injectors will bring the BPC ratio back in line."




I did that tonight. I hooked up the Original L03 ECM, with the stock Chip/prom. Started it up, sounded like it had a misfire. So Turned the distributor towards retard. and it idles a bit smoother 650rpm- in D,R, and Park. same idle all gears. So I took it for a ride. Not One Ping, but I did get 1 sudden thump at WOT. However I dont Take off at WOT very often.... very rare.. Unless Drag racing.. So anyway. I left the 350 ESC Hooked up. Not sure if i should change that back to the 305 for now. However, I have Found There is alot of Tuning to be done with that 350 Computer/chip..

Thanks, Nick Hall

 

My name is Bronson, and if you look at the top of the TBI forum you'll see a sticky called "come in for a free tune" this is a step by step guide to get you started tuning.

Swaping computers and sensors is like trying different carburetors instead of changing jets....it works but rarely in a good way.

 

well it got rid of the pinging. Which Made Me Happy! I Understand the Carburetor/Computer swapping thing.. who wouldnt.. lol Yea, I gotta get all the stuff so i can start tuning and Find some Hidden HP/TQ...

 

Well, for starters you are way on the fat side, the bogging etc. will largely go away when you start fixing that AFR. That cookie cutter chip is definitely doing you no favors, it may be a decent base line to play with, but nothing more. 11:1 AFRs would be suitable if you were running a supercharger or a turbo, but no way if you are running a N/A engine. I wouldn't be looking to throw more parts at it until I had that issue fixed, if you buck up now and start tuning your own PROMs it will also help you optimise for future modifications too, such as that cam or new heads. One stupid question before blaming the chip all the way though, have you checked the fuel pressure yet? I know it's sorta silly, but at the same time you are running a TPI pump so I figure I'd ask. I've never had any problems with my 307M Walbro on a basicly stock TBI setup, but that doesn't mean you don't have like a pinched line or somehting.

 

No I havent Checked the Fuel pressure. The pump kicks on and sounds strong... Wouldnt a Kinked line give me less Fuel/Fuel pressure at the TBI Unit? and im running a bit rich.. Right?

 

 

Yea I know I'm running Rich... But could a pinched line really mess up my Volume of fuel at the TBI unit, and make it run richer? I wouldnt think so.. Its Chip time Thats for sure..

 

hell my 90 caprice LO5 with 305 h.o. heads ,long tubes and dual exhaust ,lt1 cam pod spacer and ported TBand a tbi.com chip made this on the dyno



so your not doing to bad

 

Yea, I put the 305 injectors back in with the 305 Computer. Its Got more power with that setup. I think the 350 setup was giving just a bit too Much Fuel, Get a puff of black smoke at startup/Reving.. Im not ready for the tuning thing, but I know, theres alot of power hiding from all of us. Im in an Electronics class Right now learning about all that Electronic stuff. So I'm kinda going through my school classes, and peeking at the Tuning threads, Figuring out how much longer till i can Try to make my own Chips/proms.