Does a 98 PCM work with a 99 Engine!

**9t8z28** · 01-13-2007, 05:51 PM

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** · 01-13-2007, 06:16 PM

nope they are different.

**1fastcamarosss11** · 01-13-2007, 06:17 PM

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

**9t8z28** · 01-13-2007, 06:21 PM

Originally Posted by 1fastcamarosss11

nope they are different.

What is different?

**1fastcamarosss11** · 01-13-2007, 07:42 PM

Originally Posted by 9t8z28

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** · 01-13-2007, 07:49 PM

Originally Posted by 1fastcamarosss11

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** · 01-13-2007, 07:57 PM

Originally Posted by 9t8z28

Why then, did GM change the injector size?

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

**12secSS** · 01-13-2007, 09:39 PM

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** · 01-14-2007, 01:50 AM

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** · 01-14-2007, 05:13 AM

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

**1fastcamarosss11** · 01-14-2007, 04:45 PM

Originally Posted by 9t8z28

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

just hardest to tune.

**9t8z28** · 01-14-2007, 04:48 PM

Originally Posted by 1fastcamarosss11

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** · 01-14-2007, 05:06 PM

Originally Posted by 9t8z28

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** · 01-14-2007, 05:07 PM

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

**1fastcamarosss11** · 01-14-2007, 05:12 PM

Originally Posted by 9t8z28

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** · 01-14-2007, 05:13 PM

Originally Posted by 1fastcamarosss11

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** · 01-15-2007, 04:46 AM

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

**12secSS** · 01-15-2007, 06:43 AM

Originally Posted by 1fastcamarosss11

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** · 01-15-2007, 07:39 AM

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** · 01-15-2007, 12:38 PM

Originally Posted by 12secSS

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.