IROCKER

If this question has already been asked than I apologize for being repeatitive and please direct me to the right thread or info.

I have an 87 IROC-Z with a 350 TPI and 700R4. I thought about trying the ARAP bin on my car, but will this work? I'm not sure if the ARAP was designed for a MAF or SD setup. If the ARAP is not applicable, are there any recommendations? A friend of mine has all the burner equipment needed, so I'll be getting him to make up the EPROM for me.

needanother1

You can try ARAP on your car. Be aware that your '87 has the cold start injector, and ARAP is for like an '89, without the cold start. I simply have the electrical connector on mine unplugged for now. They do make plug kits so that you can remove the cold-start injector for good, if you wish. In order to get quick start-ups especially when cold, you'll have to make some changes to the "crank fuel PW vs. Dist reference pulse" table. In the unmodified ARAP bin, it doesn't give the engine any fuel until the eighth pulse from the distributor, which will produce a long crank before the engine fires.

You should also keep in mind that the spark advance tables in the ARAP.bin are rather agressive, and were intended (I think) for aluminum heads. To be on the safe side, you might take the values down 8-10 degrees on the high load areas to see how your car reacts.

That's my opinion anyhow. Someone more experienced than me may have some better advice.

Jason

primo

Make sure to disable VATS.

goneracin

You can use the arap bin for an 87. Like others have said, you have to disable vats, remove the cold start injector, and you also have to change a flag for the fan opperation. It is reversed in the newer bin file. ARAP has a buttload of timing in it. I have burned many many chips working with the timing tables. The fastest way to get the timing might be to get a copy of the aujm bin, copy the timing tables straight from it into the arap bin.

IROCKER

All very good advice guys, thanks!

needanother1: That's what I figured I'd do with the cold start injector, is just disconnect it for now to try it out. I curious, what would happen if it was left plug in? Rich condition? Code thrown?

Primo: Thanks.

Goneracin: What is the AUJM bin and does it offer any performance? Or is it just a stock bin used to get the timing table from?

goneracin

AUJM is, I think, an 89 350 bin. Has a more real world timing table. You can just unplug the cold start inj, but if it ever develops a leak, its gonna run very rich. I would remove it if you are going to stay with the later model ecm file ($63 vs $32). Its not needed, and can cause a problem.

IROCKER

I'm curious what happens if you leave it plugged in? Do you get a code thrown? Leaking?

Morley

No code but it may flood the engine on start. If you want to leave it in place and hooked up, just remove the crnk fuse from the fuse block, all that fues does is run the coldstart system.

jo88gta

I found the ARAP BIN's timing a little extreme for daily driving as well. Tried the AUJM and found it way to mild for daily "performance" driving. The one that worked best for my car was APYP which appears just about in the middle of the ARAP and AUJM timing tables.

Each car will be different, but I took the ARAP BIN and swapped the timing tables from the other two until I got a good starting base. From there I used the scanner and tweaked the table for optimal performance. Actually, that seems to be a never ending task.

Just something else you can try.