99 4.6 in a 97gt

[98Mayhem]

Does the computer have to be changed to a 99 also?

 

[CanadaStang]

Nope. Just use all of your electrical components from the 97"
As well as the fuel rails.

 

[98Mayhem]

I didnt think so. Here is the deal. I installed a 99 motor in a 97 5-speed gt. The car will crank and run great for about 5 minutes, then it starts having dead spots in the throttle. It gave me 2 codes which were p1152, and pp1132. I cleaned the contacts to the main o2 harness where i disconnected it for the install plus i cleaned the maf. The codes have not returned, but the car still is doing the same thing. I got a new maf just to make sure that wasnt the problem, but it still is doing the same thing. I checked fuel pressure also, and its where it needs to be. Im at a brick wall here, so any help, or advise would be greatly appreciated.

 

[Gearbanger 101]

The problem with the '97 computer, is that it's calibrated to work with a return fuel system, where the '99 is not. That's what's throwing a wrench into things! The fuel pump in the '99 is different than the one in the '97 as well as the computer calibration and returnless fuel lines.

 

[98Mayhem]

My bad i should have clarified that im using all the 97 equipment. The only thing that is 99 is the longblock,flywheel,valve covers, and intake.

 

[98Mayhem]

Well i had an idea. When the engine was out i washed out the engine compartment. In doing so water got down into the main computer harness. I disconnected it and used a blow gun and some water came out. I drove it for awhile now and it seems to be fixed. I will let ya know.

 

[Gearbanger 101]

Well i had an idea. When the engine was out i washed out the engine compartment. In doing so water got down into the main computer harness. I disconnected it and used a blow gun and some water came out. I drove it for awhile now and it seems to be fixed. I will let ya know.

I had the same problem getting water in my computer one time. The easiest way and safest to dry it out was to just put in in the oven, at low heat.

 

[CanadaStang]

Well i had an idea. When the engine was out i washed out the engine compartment. In doing so water got down into the main computer harness. I disconnected it and used a blow gun and some water came out. I drove it for awhile now and it seems to be fixed. I will let ya know.

Good to hear!!! A lot of people have had problems after washing engine/engine bay, mostly from getting water into the recessed plug holes.
How's she perform with the new engine?

 

[HIGDON]

I had the same problem getting water in my computer one time. The easiest way and safest to dry it out was to just put in in the oven, at low heat.

And this is safer than compressesd air how??? Heat is one of the top killers of electronic parts. Even at low heat, I would never put my ECU in the OVEN.

 

[Gearbanger 101]

And this is safer than compressesd air how??? Heat is one of the top killers of electronic parts. Even at low heat, I would never put my ECU in the OVEN.

Well, for one I'd take low heat over high pressure air that will potentially blow the electronic components of your ECU to pieces. And considering the amount of heat it would take to effectively degrade your electronics, you should be more concerned about the number one killer of electrical components and that’s a sopping wet computer. For the amount and the duration of hot and cold conditions these ECU’s go through in a lifetime, 20-min in the oven on it’s lowest setting won’t kill it. (Been there, done that…..nothing but positive results)! Air dry is fine, but the longer it stays wet and open to the elements, the greater chance there is of extensive corrosion.