Engine Swap From 2.3 SOHC to 2.3 DOHC HO

Ok... My Boy freind and i swaped engines between a 90 beretta 2.3 DOHC HO and a 93 Olds Acheiva 2.3 SOHC. The 2.3 DOHC HO is now in the 93 acheiva. We can not figure out why it wont run right... The computer thats in it ( for the 2.3 SOHC) will not give the car enought gas and power to run right...We gfound out that the injectors were differnt so we changes those. But when we put the computer in the achieva for the 2.3 DOHC HO it wont fire.... Please help this is getting so annoying....Thanks

You will need a computer from the 2.3 DOHC to make it work properly. The computer from your old engine is not designed to properly power the newer HO engine. If you can't find a computer change out the PROM that is in the current one with one from an HO motor equipped vehicle. This should cure the problem although a complete computer would be better.

we have tryed to use the computer from a 2.3 DOHC HO engine and i have tryed putting the prom in the original computer and it wont fire. Any other sugeestions?

Plus the 2.3 DOHC HO only came in 5 speed and we put it in an automatic.

The transmission should not have anything to do with it. You need to check everything in the wiring and sensor connections to make sure that you are getting spark, fuel and etc. If you have none of this you will need to find the problem before it will start. I would start with the ignition side first to make sure you have spark. If not check all connections to the ecm and the cps. If there is spark check for fuel. You may not be getting any fuel to the engine. You can try starting fluid to see if it will fire, if it does then the fuel system is the issue. Check the fuel pump if that is the case. Also the injectors you changed may be causing the problem. It is possible that they will not provide enough fuel to run the car or they were wired different than the ones you removed. Just some ideas on what to look at.

Ok thanks...Ill try that, the thing that really confuses me is that it will run ( just acts like its starving for fuel) with the computer from the 2.3 SOHC but when u put the 2.3 DOHC computer in it it wont start . But ill check into that if you got any more ideas let me know....

How is the trans telling your H/O ecm/prom that your in park?

The sohc ecm/prom wont run the dohc ignition module and the injectors are differant .

The H/O ecm may have to wired for the park/neutral switch, or you may need to track down a H/O auto chip, you would want a chip that is the same year as the ecm your going to use.

Some year prom and ecm's dont work together, I think 90-91 were differant than 92-(93)94 so those year prom and ecm's parts are not interchangable, a 93 H/O prom isnt going to work in a 90 H/O computer.

edit: was just thinking, could also be related somehow to the clutch switch wiring may need to be bypassed as well.. the H/O ecm isnt going to allow the car to start if that isnt closed.

edit: was just thinking, could also be related somehow to the clutch switch wiring may need to be bypassed as well.. the H/O ecm isnt going to allow the car to start if that isnt closed.


Can you tell me how to do that and where it might be loctated at?
I think that might be my problem.

The wiring for the clutch switch would be part of the 5 spd car's wiring harness I believe, in a 5 spd car the clutch must be depressed all the way which closes a switch located on the firewall to start the car, in an automatic the car must be in "park"(some will start in neutral as well)if you swapped the wiring harness out when you put in the dohc motor there should be some wires somewhere that are not connected, if you kept the automatic engine wiring harness then I think the computer would be looking for the closed clutch switch circuit becuase it is a 5 spd ecm/prom, and hence needs the clutch switch closed, not the car to be in "park".. little confusing, most people go from an auto to the 5 spd., I think a H/O automatic prom would be your fix, but Im not sure they are still available, the H/O motor came in auto and in even 4 door(Grand am, Calais Intl.) but it was very, very rare.

I THINK what you may need to do is find the correct pins on the H/O ecm for the clutch switch and make it so that circuit is closed, OR it could be that the H/O ecm/prom combo isnt able to see that the car is in park because the wiring isnt there for it(depends on which harness you used I think),again I am not 100% on all that.

I dont know the swap that well to give any detailed steps, there are several active members on www.quad4forums.com that have swapped from auto to 5 spd and I am near sure someone there will have your answer, go there and make a post or just search the site, it is the #1 place to find info on the quad 4 motors. Hope you are enjoying your H/O power soon, even if limited slightly by the auto trans.