my 87 5 speed 305 tpi 5 SPEED had a check engine light. buddy who is a mechanic says the code says it needs a new mass air flow sensor.. put one in and the car runs 100 times worse than it did before. and now it has a code 43.. he put a new cap and rotor on as well as the module under the cap..

any help would be greatly appreciated.. thanks!

 

Check the wiring to the MAF and check the MAF power relay and the MAF burnoff relay. The relay's are located on the drivers side next to the brake booster. the MAF burnoff relay is prone to failure.

 

the weird thing is that it ran 100 times better with the old mass air sensor in it.. with the old mass ir it would just try t o die when 1st started. it ran smooth afetr that.. now it will die when not on the gas and pops and spits and hesitates..

 

I would put the old sensor back on, Why did you replace the MAF in the first place?

 

check engine light was on and my buddy (mechanic) said thats the code it had..

 

buddy is telling me to try to find a new electronic spark control module??

 

my 89 has the same prob right now..won't ilde unless I hold the gas alil,if I don't it just dies right after kicking on..but I got codes for 21,33,45...starting wit the TPS first to check the voltage on it...

 

Sounds like your buddy is more of a parts swapper than a mechanic, He already had you waste money on a unneeded MAF. change the relay's mentioned above then reset the ECM. This will usually fix the MAF codes you are getting. also look for simple things that could cause vacuum leaks and cause your problems.

 

snap on 2500 scanner the old mass air flow sensor was reading 10/90 inches at idle.. new sensor is reading 28/28 at idle

 

A bad burn off relay would cause your old sensor to give a low flow reading like that, If its not working it will not burn the contaminates off the wire element for proper readings.

Here are some other threads to look at:

https://www.thirdgen.org/forums/tpi/...ll-please.html

https://www.thirdgen.org/forums/tpi/...uble-code.html

https://www.thirdgen.org/forums/dfi-...s-12-33-a.html

Do a search for MAF problem and you will get lots of info, the subject has been beaten to death on this site.

 

tried a replacement mas.. same results as the other new one.. i ordered the 2 relays.. wont be here for 3 days..

 

Code 43 is the Electronic Spark Control (ESC). I think that is the elctronic unit that is located under the distributor cap. Remove the cap, and remove the ESC unit, should be two small screws if I remember correctly. Take the unit down to a parts store and have it checked. Make sure that they test it 10 consecutive times, because sometimes a bad unit will check out good when its cool. I have had these ESC units go bad with the car just sitting around or the dizzy sitting on the shelf waiting for an engine change!

 

I'm no mechanic. But that code 43 is pretty common when an engine is running like crap. It's a result, not a cause usually. Unplug the MAF and see how the engine runs on default. Rule out the MAF circuit. Check fuel pressure yet? If not, do that next.

 

put in a new esc also.. i still dont understand why the car runs 100 times better with the old mass air flow sensor than a new one..