Does a 98 PCM work with a 99 Engine!

[9t8z28]

When I bought my car, ( 98 Z28 ) it came with an engine out of a 1999 Z28.
Heres what I don't understand. The (98)PCM is set up for 28lb. injectors, but the (99) engine comes with 26lb. injectors. How is this making my engine run? Theres no check engine on. Would they have had to tune it? What difference does it make with them being 28lb. and 26lb. ? How can I tell the difference between?

[1fastcamarosss11]

nope they are different.

[1fastcamarosss11]

that small of an amount on the injectors wouldn't matter, or even really be to noticable.

[9t8z28]

nope they are different.

What is different?

[1fastcamarosss11]

What is different?

from what i have read, in 98 the pcm can go either auto or m6, 99- 02 has to have one or the other. hence m6 pcm with m6 trans.
but i also read recently that there is an adaptor for that. someone will clear this up i'm sure.

[9t8z28]

that small of an amount on the injectors wouldn't matter, or even really be to noticable.

Why then, did GM change the injector size?

[1fastcamarosss11]

Why then, did GM change the injector size?

probably because it was cheaper and that little bit didn't effect much. :yup: :)

[12secSS]

The 1998 ECM will only work on a 1998 Engine Harness, it has nothing to do with the engine. The previous owner possibly swapped the injectors from the 1998 car to the 1999 engine.

Also a 1998 PCM will work on a manual or auto, it is in the prgram and can be flashed to either. Same thing with a 1999-2002 PCM ... you can use them on either auto or manual, it is just a simple reflash for the proper trans.

Basically, don't worry about. :)

[LS1-68]

I´m gonna do tune, I need engine control only .
Does it matter which car computer comes, if it´s gonna be reprogrammed? Supposing that, harness is fixt for given sensors.

Do all ls1 ecm:s have same internals, or is there more differences than programs?

[9t8z28]

Well, from what I have heard, the 98 PCM is the worst one!

[1fastcamarosss11]

Well, from what I have heard, the 98 PCM is the worst one!

just hardest to tune.

[9t8z28]

just hardest to tune.

What do you mean by that? What will be the difference in tuning my 98 PCM compared to a 99> PCM?

[1fastcamarosss11]

What do you mean by that? What will be the difference in tuning my 98 PCM compared to a 99> PCM?

tuner say it is harder to tune the 98's, and some charge more.

[9t8z28]

Is it posible to convert my car to a 99 PCM? What would it take?

[1fastcamarosss11]

Is it posible to convert my car to a 99 PCM? What would it take?

i would guess just wiring, check the tech section here i think someone has done it but i can't remember.

[9t8z28]

i would guess just wiring, check the tech section here i think someone has done it but i can't remember.

Thanks man! You've been a big help!

[98Camarod]

If I had to guess why the injectors are slightly larger it is probably due to the slightly larger cam in the 98.

[12secSS]

tuner say it is harder to tune the 98's, and some charge more.

I would not go to a tuner that says that. Tuning a 1998 ECM is no different then a 1999+. Many of the fastest cars were running OEM 1998 computers back in the day. I do not charge extra for a 1998, because they are not harder to tune. Granted, there are some tables that are not available to 1998 as there are to 1999+, but you can still tune the idle, part throttle and WOT just that same and with great results.

[9t8z28]

Allright. The next step is to find someone good to tune my car on the EastCoast. Bolt-ons exc.exc. Anybody know of a good tuner near Philadelphia?

[Wesman]

I would not go to a tuner that says that. Tuning a 1998 ECM is no different then a 1999+. Many of the fastest cars were running OEM 1998 computers back in the day. I do not charge extra for a 1998, because they are not harder to tune. Granted, there are some tables that are not available to 1998 as there are to 1999+, but you can still tune the idle, part throttle and WOT just that same and with great results.

Finally someone who knows what they're talking about, from experience, regarding the 98 PCM. Thanks for the input.

[Wesman]

Allright. The next step is to find someone good to tune my car on the EastCoast. Bolt-ons exc.exc. Anybody know of a good tuner near Philadelphia?

Thats what I'd like to know too. After I do Headers and Exhaust, I'm going to try and get it tuned. Seems like all the tuners are out West though...

BTW: Hows that true dual exhaust you fabbed up coming?? Are you going to be producing them? I was very impressed with the prototype, come Spring I'd like to buy that system from you if at all possible :)

[12secSS]

If you guys are close to Trenton, NJ look up foff667 (Bill). :)

[9t8z28]

Thats what I'd like to know too. After I do Headers and Exhaust, I'm going to try and get it tuned. Seems like all the tuners are out West though...

BTW: Hows that true dual exhaust you fabbed up coming?? Are you going to be producing them? I was very impressed with the prototype, come Spring I'd like to buy that system from you if at all possible :)

You talking to me WESMAN?

[Wesman]

You talking to me WESMAN?

Yea, sorry should have made that more clear ;)

[9t8z28]

Yea, sorry should have made that more clear ;)

I found a guy to tune my car. He's close to Philly. I will know more when I get in contact with him. I will let you know.
As far as the true duals, they are on hold. Basically, I made the proto-type and a couple of hours latter after it was finished, some dude cut me off on the road. Demolished the car. The proto-type exhaust made it though. Since I started the project, it is up to me to finish it. Well I have been out of work on disabillity since the accident on August, 11. I will be going back to work in about a month and I will keep in touch with the progress of the true-dual.
What headers are you going with?

[Wesman]

I found a guy to tune my car. He's close to Philly. I will know more when I get in contact with him. I will let you know.
As far as the true duals, they are on hold. Basically, I made the proto-type and a couple of hours latter after it was finished, some dude cut me off on the road. Demolished the car. The proto-type exhaust made it though. Since I started the project, it is up to me to finish it. Well I have been out of work on disabillity since the accident on August, 11. I will be going back to work in about a month and I will keep in touch with the progress of the true-dual.
What headers are you going with?

I'm really sorry to hear about that man. Best of luck in your full recovery.

I'm most likely going to go with the XS Stainless Steel headers from eBay. Normally I wouldn't buy eBay parts, but many people have had good experiences with those, and you can't beat them for the price. So as of now, thats what I'm figuring on.

Like you mentioned, keep me updated on the progress through PM's if you can. I'm definitley interested in purchasing that system from you, it looks great. I'm looking at doing the exhaust as soon as the weather changes, probably in March or somewhere around there.

That tuner sounds promising too, we'll keep in touch.

[9t8z28]

Yep! I'll PM ya. I am going with the same headers. I might do a ball flange instead of a collector reducer or a slip-fit. I'll hook ya up.

[Wesman]

Yep! I'll PM ya. I am going with the same headers. I might do a ball flange instead of a collector reducer or a slip-fit. I'll hook ya up.

Sounds awesome, I think the ball flange is a great idea.

Thanks again :)

[Street Lethal]

I do not charge extra for a 1998, because they are not harder to tune. Granted, there are some tables that are not available to 1998 as there are to 1999+, but you can still tune the idle, part throttle and WOT just that same and with great results...

Agreed.

Heard similar things about the infamous '98 PCM when I bought my car, and laughed the very night I installed the heads and cam. Been tuning engine's ever since the advent of TPI, and tuning the '98 went very smooth, even with the more aggressive LSK lobes.... ;)