OK, here is the deal. I have an 87 Camaro LT that was originally a 2.8 V6. Currently is has a 92 Camaro 305 LB9 engine. The TPI is a mixture of 86 and 89 parts. The intake manifold is from an 89. I managed to acquire it because the 86 manifold wouldn't work because of the different center bolt angles. Since 89 vehicles didn't use a cold start injector I had to locate an 89 driver side runner. The ecm is from an 86 as is the ecm wiring harness. The distributor is an 86 with a hardened gear because of the roller cam setup. Now this engine is running great, but because of the lack of a cold start valve it starts a bit rough. So this brings me to my question. 89 was the first year without a coldstart valve. What did GM due to make up for this? I assume that they changed the injector pulse width for the first minute or so that the engine is running. Now I know that 90 was the first year for speed density, so I figure 89 is somewhat unique. I also did some checking and 86-89 uses the same computer. So I am thinking what I need is an 89 chip with some custom variations for things like the fact that my cam is different. Any thoughts would be greatly appreciated.

[This message has been edited by cdartz (edited February 22, 2001).]

 

You have two options.

1) Use your 86 intake.
I know of alot of guys that have gotten over that center bolt angle problem by elongating the holes and maybe grinding the surface to fit the head of the bolt.

2) Get a 89 Chip
I'm not near as knowledgeable about ecms as the guys on the Prom Burning site but, from what I gather you could plug a 89 chip into your 86 since they have the same ECM ID (Would someone please verify this, I'm not positive!). I'd like to get rid of my cold start valve also. The 89's and later the regular 8 injectors to provide extra fuel during start up.


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87 IROC 350
Mods: 3:42 Torsen, pocket ported 083 heads, complete Edelbrock exhaust, Most free mods, Most little mods, aluminum d/s. Edelbrock STB, boxed rear suspension pieces, urethane bushings everywhere.
Stock cam, chip, runners, base, and trans
13.94@103mph, 2.25 60'
Recent stuff: SSM sfc's, Homemade relocation brackets, Ported SLP runners, ported base, EGR!
Current/future projects: homemade torque arm, and 27x10 Hoosiers (need wheels!), and Prom Burning
Planning new engine build, possibly 383 w/ TFS 23*

 

CDARTZ...one problem you may have using an '89 PROM which some people forget about is VATS. 89 cars had VATS and therefore it is programmed into the PROM itself. I'm not saying you definitely will have problems, but you may. Stan is correct in stating that GM added an enrichment cycle on startup to take the place of the 9th injector. either manifold can be used, it's just a matter of elongating the center bolt holes for use on later/earlier heads. Now you said something about an 89 PROM with some custom programming? Well, IMO, that is what you would need. You can have all the benefits of no cold start injector, plus have VATS programmed out of the PROM and then compensations made for whatever cam you have and other mods. I believe you can order a non VATS PROM from GM also. May be around 150. I'm digging this out from my memory so someone may be able to verify this.
Best of luck

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-Bill

-=ICON Motorsports=-

Modertor TPI board

Looking for 86/87 Turbo regal
1991 Z28 SOLD

 

Check this post out from the Prom Section about changing to a 89 $6E calibration.
https://www.thirdgen.org/messgboard/...ML/000602.html


------------------
87 IROC 350
Mods: 3:42 Torsen, pocket ported 083 heads, complete Edelbrock exhaust, Most free mods, Most little mods, aluminum d/s. Edelbrock STB, boxed rear suspension pieces, urethane bushings everywhere.
Stock cam, chip, runners, base, and trans
13.94@103mph, 2.25 60'
Recent stuff: SSM sfc's, Homemade relocation brackets, Ported SLP runners, ported base, EGR!
Current/future projects: homemade torque arm, and 27x10 Hoosiers (need wheels!), and Prom Burning
Planning new engine build, possibly 383 w/ TFS 23*

 

Hey thanks guys. I think that was just the info I was looking for. I know someone who can burn me a chip, so now I know exactly what to let him know that I need. Thanks.