Will a 88 computer and chip work in an 85 SE V6 with no wiring mods? (Page 1/1)
cvxjet MAR 26, 04:16 PM
I have an 85 SE V6 that I have converted to a 3.4 F-body and Getrag 5 spd.......It does not run completely happy.....full out it goes great, but in slow to stop-n-go traffic it has jerky throttle response...I have switched out every sensor and also swapped in a new/rebuilt 1985 computer which had little effect.

I have an 88 computer and the chip for it.....Do I have to move any wires around or is the computer and chip just a plug and play?
Raydar MAR 26, 06:59 PM
If your 88 ECM has a manual tranny chip in it, just plug it in. As long as you don't mix up the chips, you should be good.

Don't be surprised if it acts completely the same, though.

Have you adjusted your TPS? It might need more of a "pump shot" (or the electronic equivalent.) I've seen that before.
Also check your timing. I had the best luck, setting mine by ear.

[This message has been edited by Raydar (edited 03-26-2019).]

cvxjet MAR 26, 09:53 PM
Raydar....Which Injectors did you use? I was given a set of bigger injectors (I believe the ones for the F-body 3.4....My computer would not run them right. I ended up using the original injectors. One of the reasons I wanted to switch to the 88 computer is that it supposedly is set up so it can run the later injectors.

By the way, just to clarify....I mean a 3.4 F-body Long-block under the original Fiero induction system....
Dennis LaGrua MAR 27, 12:05 AM

quote
Originally posted by cvxjet:

I have an 85 SE V6 that I have converted to a 3.4 F-body and Getrag 5 spd.......It does not run completely happy.....full out it goes great, but in slow to stop-n-go traffic it has jerky throttle response...I have switched out every sensor and also swapped in a new/rebuilt 1985 computer which had little effect.

I have an 88 computer and the chip for it.....Do I have to move any wires around or is the computer and chip just a plug and play?



The 85 V6 computers are different than the 86-88 ECM's and the chips use different programs but your problem is probably not the ECM. Jerky throttle response sounds like a fueling or ignition problem.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
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fierofool MAR 27, 08:09 AM
I developed a jerky start with my 3.4 and found that it was a bad transmission mount.

Regarding fuel injectors: I am running a Bosch injector that was recommended by an injector company. They have served me well, but we know from scans Raydar has done on the car that it is running lean.

Previous experience with the Mustang 19# injectors in another car proved to run rich, but liveable. The second car with the 3.4 got the original 3.4 Rochesters and they would put a diesel to shame.

I worked extensively with another PFF member to find the correct injectors for the 3.4 upgrade. After trying several different injectors, we finally settled on the bosch 0280150415 injectors. They are a Generation 2 injector. Being second generation of the injectors I am running. The injectors are pintle injectors that were upgraded to a 4 nozzle spray. This increased the flow from 16# to 17# at 43.5 psi (3 bar). This is the exact requirements for the 3.4 and matches the flow and pressures of the original 3.4 Rochesters. What makes these injectors correct for our upgrades is that they are pintle style injectors instead of disk style like the Rochesters. Our stock ECM's can operate them properly.

BTW, injectors do not flow as much as they are rated at. The standard pressure used is 43.5 psi. A 15# injectors flows less than 15# and a 16 flows less than 16. Don't be misled by the flow rating of 16.76# for these injectors. Most 17# rated injectors only flow about 16.66#

https://www.injectorplanet....cts/bosch-0280150415

https://www.ebay.com/p/Fuel...15/74581539?thm=2000

[This message has been edited by fierofool (edited 03-27-2019).]