Hi guys, i have some questions for you. first off i bought a 87 trans am with a L98 (body was finished) so i took the engine and put it in my 86 camaro wich had a 305 tpi before. will a L98 work with the wirring of the LB9?. because i have all the L98's wireing in my garage (not the computer though). also the L98 when it was in the trans am had a MSD ignition system. it is still hooked up the the L98's original harness. would i see any differance in performance if i swaped it back to the L98?. also my L98 if pritty ruff at idle, it doesnt shut off and runs very good and make good power. but at idle it gets very frustrating it just vibrates alot, so i put it on N and it vibrates less.

 

The wiring itself should be same or similar. However, you will need to find a prom chip for an 86 350 TPI, auto... or burn your own.

Depends on which MSD ignition your talking about? 6A box, coil, wires, what?

Sounds like you have a vac leak.

 

its a 6A box only, and where could i find a "chip" or get one burned?

 

The 6a seems to only help in the very high RPMS from my readings. So if you plan to run the motor constantly above 4k or so, use it. If not, the stock will work fine.

First you need to see if the 86 came with a L98. If so, look in the parts section, or tpiparts.???. Burning one yourself would be best as you can adjust it for your motor, in your car, to your driving. Cost more up front, but is worth it in the long run. Go to the DIY prom board on this site.

 

My god i dont understand anything about proms and prom tunning. is a prom the chip in question? and what do they meen when they say burning your self one? what can you adjust and how.

 

Prom=Chip in computer, and item in question.

Burn yourself one= editing the into, and you burn an image of that tune into the chip. Then you install it into the computer. Some easier then others.

What can you edit? Honestly depends on what PCM, engine, and other info. Main thing is the fuel table chart(VE). But you can adjust many other things.

 

thanks you dale. very good info!

 

I would think your best/easiest bet would be to just buy a complete computer/chip off ebay or somewhere like that. I just bought one off a guy on another forum for $60/shipped from Canada to the U.S.
I would think one for an 87/88 f body w/L98 would be what you need.
I don't think f bodies even came with a 350 until 1987, but vettes did before that.
Someone on here should easily be able to clear this all up for you.

 

they started the tpi in 85 but i think the l98 was producted in 85 also but was only available to the public in 86. but do i need to get a 87 chip or a 86? because my l98 has the valve cover bolt on the side and my LB9 had them on top.

 

l98 350 first came out in camaro 1987 85-86 camaros had 305s corvette had l98 350 starting in 85 up

 

It would be more for the ECM/Wiring that you have rather then the motor itself.

 

Using the ecm and prom from the 87ta shouldn't cause any problems, try that to see how it runs and then upgrade it later if you think it needs it.

 

Good luck with that.

 

Corvette...........

I would just use a computer/chip from any 87/88 L98 from an f body, they are everywhere.

 

As I said later. I dont know if one came in 86. I also dont know what years, what ecm came on what motor tell the 91/92 models.

He needs to find out what ECM he has. Then find, or make a prom chip for that motor, for that ecm/wiring.

 

From '86 to '89 ALL the TPI's used the same ecm regardless if it was a 305 or a 350, the only thing different was the programming on the chip.

The ecm from your 87 t/a donor car will have no problem running the 350 that you swapped into the 86.

 

i do not have the 87 T/A its bin scraped and striped. and what differances would i see from running my 305 chip and my 350 chip?, performance??. and what will the knock sensor change?

 

Your car shouldn't run too badly with the 305 chip in it, but you won't get the best performance possible.

If you still have the chip from the 350tpi use that instead. Barring any mechanical problems the motor will run the way it was designed to.

If you still feel you want to upgrade afterthat, there are a lot of aftermarket chips available, do a search here for more info on those.

 

well i find my 350 makes very good power. just ruff on idle. i think i will order a stage 1 jet chip. will i see a big differance from the 305 chip to the jet chip or will it just fix the idle problem?. also i checked my timing and it is very advaced, mabey 2 inches away from the metal degre plat. i tryed putting it at 8 degrees and it runs way to rich. but runs good when it is advanced... could this be affected by the 305 chip?

 

When your checking your timing, are you disconnecting the timing wire?(or whatever the 86/87's have to have done to remove the computer advace).

 

^^^^^ I was going to ask the same question^^^^^^

Also the timing should set at 6 degrees.

the timing bypass connector comes out of the large wire loom on the passenger side firewall near the ac unit. It's one wire with a weather pac connector on it it looks kinda like a fuse holder. Setting the timing properly will probably take away some, if not all, of the roughness.

The only real difference between the chips is the injector constant
the 305 chip is looking for 19# injectors while the 350 chip is set up for 22# injectors. The ecm should be able to compensate for the difference.

If you haven't done so already, I would suggest a new set of spark plugs, and double check your wires to make sure none are crossed or damaged.

 

Dont worry guys i did my home work. yes i did disconect the advance thingy. also my spark plugs are about 1 months old and my spark plug wires about 3 weeks. il start by changing the chip and i also have a full Accell distributer kit in my Trans am. like wires every thing. i will give you guys some news with the power differance. mabey take it to the track. see how a stock L98 does with the chip.

Jazz