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After reading the post below on engine issues, which i have the same symptoms ,is there a differance between MAF sensors from differant years. My car ,1990 legacy with a 1991 ECU and I believe to be a 1992 engine is throwing codes 14,15,16,17,24,32and 49. IT will run fine at idle and will rev in nuetral with no problems,but once on the road it has loss of power and bucks at stedy RPM's . I have tried three differant MAF and after putting one on from a 1994 ,which i know is good,the car ran good for a mile or two then began to run like crap. Any ideas?

the mafs from the automatics are differendt from the sticks and will throw your code 49. as for the other codes there are some good posts to find out what they are just serch for them.

OK the MAF i have on the car now is from a m/t 1994. So i should be good there? Yes the other codes are all from all 4 injectors. I wouldnt even think it would run if they were all bad. and the 24 is the IAC. I think that just does the idle and wouldnt affect the engine in upper RPMs, M i wrong?

i think you need check timing belt and make sure the correct marks are lined up, correctly lined up that is.

Yea IAC will only affect idle, shouldnt effect running at RPM, I would look into those injector codes though, esspecially with the code 34, i would bet money that if you check out the injectors and their harnesses and replace the O2 sensor, that would solve your problem

I don't think the MAF is the issue here. I think the ECU is the problem. If you have a 1992 engine, the Injector's are definitely different than the ones the 1991 ECU is used to. I would focus in more on that than the MAF. How about you find a 1992 ECU and use that.

Thanks for the advice. I think what im going to do is put in a 1994 ecu and injectors along with 94 MAF from a parts car i bought. I know these parts are good because its running now with no codes. I hope there is nothing differant in the wiring harness from the 1990 to the 1994?. Its funny sometime the car will run fine as it is now.

Everyone's touched on some of the issues. I'll try to explain everything in more detail.

The 90-91 MT n/a legacies use a different set of electronics then the 90-91 AT n/a legacies. The MT cars used a hitachi ECU, MAF sensor, and had a ball nozzle type injector. The coil pack & ignitor are also different, but that doesn't matter. The 90-91 AT cars used a JECS ECU, MAF sensor, and had a pintle nozzle type injector.

The 92-94 MT & AT cars switched to the JECS electronics. The MAF sensor is the same as the 90-91 AT cars, however the injectors are different then the 90-91 AT cars.

You need to match up the ECU to the injectors & MAF sensor you have. If you have a 92 engine, you need a JECS MAF sensor (black plastic housing) and 92-94 n/a ECU.

The other thing to mention. The engine electrical harness did change over the years. The 92 should have only two square plugs, while your 90 legacy had three square plugs.

So I would verify/check whether things were re-wired, or if the engine electrical harness was just swapped over to the 92 engine, OR if your entire 90 intake manifold/electrical harness was swapped onto the 92 long block.

It sounds like you've got some weird issues going on, but we need more details to accurately diagnose the problems.

OK what i did was take the ECU, Injectors, and MAF from the 94 and out it into the 90. Everything bolted right up and the car runs great now with no codes so i guess im good to go. But if i understand what legacy777 is saying the MAF will work if its an a/t or m/t as long as its the same brand now matter what the year? Just so i know in the future so i can use the ones i have for a backup. and what plugs were you reffering to when you say 2or3 plugs.

legacy777 never mind on the plugs. I see what you are saying. I have three plugs on mine so i guess the engine is a 91? I cant remember what year the car was i took it from its been 3 years or more.

Did you swap fuel rails when you swapped injectors? You need to.

Yes i did.Thanks