Hello all!!!! i have a very funny car for you all. it is a 1984 Fiero with a caddy 4.9 motor in it. ok here is the kicker. it has some mustang in it. The computer system is a ford 5.0 H O MAF EEC IV from a 1990 mustang. it does have 2 new O2 sensors.
Ok the problem i am having is it idles rough as heck and likes to stall. also every time i start it up i let the motor run for a good 2 min and then take off. when i get on the highway it seems to starve for gas. what would cause this?

here is a bad video that i took. not enough light. http://www.youtube.com/watch?v=LofqWiOdMu0

any info would be much helpful. thanks

 

wow, trippy!!! You're a little lucky, have both cars, but never in the same body, lol...anyway's, not sure how you got the stang ECU to work with the caddy motor, but I know the stang injectors was a popular upgrade for the caddy motors. I htink you're gonna have to give alot more specs about yoru combo, but the best thing is, can you run a wideband meter? Also a fuel pressure gauge (the caddy fuel rail has a standard port to check fuel pressure) and check the readings while driving, also check for spark issues too.

 

Im not sure what all specs you need for this build?? im not the one who has built it so i am kinda lost. im not to big on computers and it sucks because i am sooooo lost. as for the spark. i think it is getting good spark. it dont backfire at all. 90% of the time (im old school 1/4 mile) when you have back spark it wont run good and will backfire.
i do have know how on motors but like i said only old school.

 

if its never been tuned, it would be a really good place to start

 

no it hasnt as far as i know. when i talked to the builder he told me its a stock reman computer.

 

step #1... find a mustang tuner
Step #2... Get that thing tuned

 

ouch they cost a chunk of $ that sucks because all i need it for is one time and to pay 300+$ for one is unreal

 

Thats why it's priced how it is.

 

Well i checked the classifieds and i cant post in the wanted adds till im a member for 30 days and have 50 posts. i only like to post if i can help others or if i need help therefor im not into being a post hog.
if anyone has a tuner they would rent out or sell for cheap i would love to know
also if i dont find a used one or such what kind of tuner should i look for? there are so many of them with all different prices. i just need something easy to fallow but at the same time price is a big issue.

 

apparently you misunderstood what I was telling you. You need to bring your car to a mustang performance shop, and have a dyno tune performed.