Annoying Engine Miss- Dodge Stealth

[DeltaDart]

I'm new to Cedar Rapids and was told about this site. Great site. I own a 1992 Dodge Stealth R/T with the 3.0L DOHC non-turbo. It's a 5speed with 138,000 miles. The car has a miss to it and I simply can't find a fix for it. I will describe the miss.
When the car is at idle you can hear a very "slight" miss. When you run it through the gears the engine feels like it's "bogging" down. When you take it slow through the gears the bogging down is not as noticeable but it's still there. The miss it at it's worse when you are going 30mph and you try to maintain that speed. When doing this the engine will buck back and forth. The car starts fine and it idles well. I have done the following to the engine to try and fix the problem- New plugs and new plug wires. New O2 sensor.New fuel filter.
Sent the injectors in to have them tested and rebuilt. Test showed they were in good shape to begin with. I had another engine and I swapped the following parts: CAS sensor-The 3 coil packs-Fuel regulator-TPS sensor-VIC motor. Have done test's with a multimeter and everything(TPS-VIC-IA-IAC)checks out. I pulled the fault codes and there were none. CEL has never come on. It's not burned out.
I'm thinking of buying a MAF sensor but have been told that if the MAF sensor is bad it will throw a CEL. Since there is no CEL i'm assuming the MAF sensor is good. This I could be wrong on. But everything that I have read about the MAF sensor says it will trip the CEL. Is this true? In the past I've had 02 sensors go out(92&95 Dodge Spirit)and neither one of them tripped the O2 sensor.
Maybe the MAF sensor does the samething. I just don't want to start throwing new parts at it. Is there a good way to troubleshoot the MAF sensor? I also have read where the fuel pump could be the problem. In the past when a fuel pump went bad the car would simply not run. Never had a weak pump. It either ran or it didn't. Have never checked the timing either. So what do you think? I would really apprciate you input. Thanks! John

[TbTalon94]

Sounds like you've done most of the regular check-ups on this kind of thing. I would try to find a known working MAF, swap it and see if anything changes. The fuel pump COULD be the problem but it would more then likely just run like complete crap all the time. You could swap in a working one to see if it fixes it. You also might want to take out the ECU to the car, open it up and look for any corrosion or burnt transistors. The 1st gen DSMs (90-94) have a big problem with the Capacitors leaking on the board and it causes all kinds of things to mess up. I know the Stealths/3000gt's ECU's are very similar. Might want to check that out.

I would find a known working MAF and fuel pump. Switch one at a time to see if anything changes. Then open up the ECU and see if anything looks corroded or anything like that.

You say you replaced the Coil Packs, how about the ignitor? It is a little transistor that gives the coil pack the information to spark. Stealth's may have 2 of them, where as DSMs only have one. They are one of the main problems of ignition problems on DSMs. Might want to check that as well.

-trevor

[DeltaDart]

Many thanks for your input! I forgot to say in my post I did remove the ECM and everything looked very good. I'm told it could still look that way and still be faulty. I wish I could find someone with a MAF sensor and swap and see if that's the problem. Nice thing about this engine is it's quite easy to change parts on it. The MAF would take less than 5 min. Have not checked the ignitor. Will do some research and see what I come up with. About 3 weeks ago I was talking to a former Stealth owner and he said this is a very commom problem with the DOHC engine. His had the same problem but he sold his the way it was. He got frustrated that he could not find the problem either. Do you know someone with a MAF sensor that would fit my Stealth? I'm sure they used them on other models.Again thanks for you post. Will see what happens. John

[TbTalon94]

The MAF you are looking for comes on a variety of cars. Any 95-99 Turbocharged Eclipse or Talon. Any year 3000gt or Stealth...turbo or not. You can use the Evo 4-9 i believe Maf (don't quote me), and some years of the Galant. All in all you should be able to find one fairly easily in any local junkyard. If not you can hit up Ebay and they have them on there ALL the time for good prices.

-Trevor

[Drifte]

i actually have one for sale. 2gmaf

but this sounds somewhat ecu related. Did you have the timing checked after installing the cas? this could be the problem, you may have accidently advanced the timing a lot. The problem is, even with a bad ecu typically you will still get a CEl. Check every sensor, as even the oddest little thing can cause strange problems. A gunked up fuel pump can cause similar problems as well. I your nearing 100k these things ought to be changed anway, so dont feel to bad throwin a little money towards a pump.