Check engine light on after repair

I just replaced fuel pump and tps on my 1989 Dodge Dakota 4 cyl truck. Now it idles rough and the check engine light came on. I have removed battery cable to reset computer but did no good. What could be the problem now? I have since replaced the plug wires and distrib cap and it is flashing 3 5 5 twice now?

We need to know the code that caused the CEL to come on. Auto parts stores will read this code for free, unless you’re in California. Go get it read and report back here.

I checked with auto zone and oriellys and they said my truck was to old for their equiptment to read.

Try this: http://dodgeforum.com/forum/1st-gen-dakota/182034-obd-1-codes.html

It would also be helpful if you gave everyone some actual info. E.g. we don’t even know why you replaced the fuel pump or TPS. We don’t know how many miles are on it, how old the plugs & wires are, whether a new fuel filter went in with the new pump, etc. etc.

Oh, I’m sorry. I didn’t notice the year. Turn your key from off to on (not starting the engine) 3 times, leaving it on the third time. Watch either the odometer or the engine light (depends on the year - your manual will tell you). Count the flashes. They’ll come in groups of two, so for example a code 14 would be one flash followed by four flashes. There might be more than one code, so keep counting after the first two flash groups. Flashing 55, if I recall, means it’s gone through the cycle.

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here. 

Added response:
Sorry I missed the age of the car. Too old for the usual error codes.

JEM - its a 1989. Instructions were given above.

I did that and the code is 35. Thx so much for ur help!

Code 35 is an error in the cooling fan circuit. This won’t cause a rough idle - unless you’ve let it overheat & blew your head gasket or something.

I’m still waiting to hear all of that other info, such as why you replaced the fuel pump & tps to begin with and what kind of shape everything else is in. Included in that would be whether you’ve actually checked the fuel pressure (ever).

5\7\11 Same truck now it is flashing 3 5 5 can that be–I checked it twice.

55 is just the code for end of error messages. So that’s not a mystery. I think you need to look again to double check what you saw before that.