OKAY. I'm new to the world of camaros. All my buddies have 5.0 foxbody 'stangs so....

I bought the following about a week ago for $5500:




1989 IrocZ28
Originally a 305TPI Auto

Powertrain Info
350 c.i. 1 piece seal truck block
New .030 forged federal mougal pistons. Approx compression is 9.9 : 1
Block and Crank were magged.

New Crane Hyd Flat Tappet Cam, .450 lift, 238 dur.
New Crane springs, keepers, retainers, pushrods, and double roller timing set.
New Proform 1.5 ratio roller rockers.

New melling high volume oilpump
New high volume water pump
New chrome oil pan and timing cover

Vortec "Ramp" style Heads
Ported and Polished. 5 angle valve job.

TPI is still stock parts, but has a killer powdercoat job, ask for pics.
PCMs For Less custom chip

700r-4 with B&M Stage 2 shift kit
Mild Stall Converter
Engine and Tranny have less than 15000 miles on them. Body has under 160,000.

Other Chassis info...
Hotchkis Frame Connectors
B&M Tranny Cooler
Ceramicoated Shorty Headers, Custom 3" exhaust with Flowmaster Muffler
Deleted Air pump
3 core copper/brass higher capacity radiator w/ dual electric fans


Problem:
when starting for the first time (cold start) it takes a few seconds to turn over and once it finally does fire I can only keep it running by giving it gas. The idle immediatly drops to around 400rpms and bogs out if I don't give it gas. I can drive the car and the engine runs fine after a couple minutes. I drove the car for a few hours and shut it off and on about 10 times in a 4 hour period and didn't have one problem.

I'm thinking this has something to do with the IAC valve or one of the a/f regulators/sensors. Any suggestions?


Also:

Any suggestions on mods?

I've never heard of a Crane cam this guy says this car has with dur and lift he has listed...is this just me or could I use a better cam?

i'm thinking the kid who did the build on the engine with his "shop instructor" did a shotty job and he had no paperwork. The car runs and drives fine and a mechanic checked it out and verified most everything...I'm just worried something is not quite right..

Lastly...being that the approx compression is almost 10:1 I'm assuming nitrous is my only option if I want a real power adder. Any input on this? Should I stick with the 2.73 gears or upgrade to 3.73s even if I do run nos?

Once again I'm new to this...so please be patient. Thanks in advance to anyone with input.

 

slick car!!!
Sounds sweet. Is this a board members previous car? Looks familiar.

Yea, those 2.73's are brutal, toss 'em. With TPI though, you don't want to go too high, 3.42's would work i'd think, but 3.73 would just leave you in a cloud of tire smoke... (not really a good thing ).


You know, I thought the same thing about that cam, 238/? with .450" lift seems REALLY tame as far as lift goes... Perhaps a circle track lift limit cam? not really a good match for a TPI motor. That's a roller block isn't it? (1pc seal..) So you could go to a factory roller setup, but you'd need to change a fair bit. Maybe just a more agressive (more lift), with less duration, for the cam. That'll run better with TPI.

I'm guessing you need a fair bit of computer tuning for that cam, and motor setup. Not my area of expertise, but there are boards for prom tuning, they can help you more there I think. That stuff is probably all you need to get it running right.

yea, even nitrous is dicey, since you have no ring gap specs or anything. I think a 100HP shot max, as a wet system. Drop down a plug heat range or two if you go that route. But I think you'll be happy powerwise once it's running right.


rock on, and welcome to the boards!

 

ok, making the same post on 3 different forums is annoying. Don't do that. you'll get different opinions on each thread, and have no idea which direction to go. Everybody gets confused, and it just gets messy.

Stick with one thread. First i'd say get it to idle right, with all the parts in it as is. Get it running best. Then check it's power output at the track. Then look into upgrades, staying N/A first. Then toy with the idea of forced induction like nitrous.

 

I would check all the connections in your runners. air may be getting in and causeing it to run lean. then when it heats up it expands and seals it. just an idea.

 

I doubt you have Vortec heads, i bet they are just crappy truck center bolt valve cover heads. Do you have a new base for the tpi?

 

Sonix - Yea sorry about posting three times. I jsut seen people get BASHED over and over for posting questions that don't relate to the forum. I figured to answer any of the questions adequately one would need a little backround info on the car to give any solid advice...so I posted the nitrous question under 'power adders'...the idle problem under 'misc engine' and 'rebuilt engines' simply becaus e this car does have a new built engine.

Honestly, I don't mind different opinions...at least then I could weed out the bad advice from the good with the help of others.

I'm definitely going to focus on a complete tune up, a trip to the track and to the dyno before adding nos. I just replaced 6/8 spark plugs with bosch platinums +2 and 8.8mm accel wires and an air foil. I'm gonna go ahead and do the oil change with mobil1 synthetic with a performance oil filter and fuel filter tomorrow...not to mention a new PVC valve.

My friend has all the tools and bells, whistles and lights to help me advance my timing. So I'm gonna do that as well tomorrow.

ME Leigh - if by base you mean plenum then yes. It is stock. from what I was told the entire TPI unit is stock.

One other thing...

So I cannot find a way to get 2/8 spark plugs removed. I believe they are the plugs for cylinders 6 and 8. the problem seems to be the header pipes...they are so close it almost impossible to get to enough room to torque the plugs. I tried a swivel socket wrench...shorty deep well socket with a shorty socket wrench...I even tried just a regular wrench to turn the socket. I couldn't fit anything in there. Any suggestions or should I just leave this job to the shop?

P.S.
Someone told me upgrading from stock injectors (I think 19#...correct if wrong) to say 26-30 lbs. injectors is a complete waste. Is this true?

P.S.S.
What should I advance my timing to with all the mods listed? Is compression easy/cheap to get verified by your local auto shop?

P.S.S.S.

what about that ram-air from fog lights using a/c ducting mod listed on this site? Is this worth it compared to simply upgrading to K&N filters or should I just upgrade the entire intake pipe to filter and spend about $200 more??

Again. thanks in advance.

 

You say that the engine was a 305 before.... Are the fuel injectors still the same stock ones that came with the 305? If so, they are too small for your new 350 engine. That may be why it's so hard to keep it running after a cold start....

The 305's came stock with 19# injectors, 350's came with 22# injectors. With your high compression pistons, you may even need to go up to 24#, in which case you will also need to get a new PROM burned with the higher injector constant.

One more thing: The 305 ECM should have also had a PROM swap to go along with the 350 engine swap. Did that happen, or are you running the wrong PROM for your engine?

 

To be honest I'm not sure what prom is running although I am pretty sure there are 19# injectors.

 

Most likely still has the 19lb PROM too then. You could open the ECM box and read the label on the PROM. It will show something similar to APYS 9350, which you can then cross reference to find out which type of car it belongs to.

I'll bet your burning lean.