1994 Ranger w/ 4 liter engine questions----

[dpfurby]

I have a Ranger with the 4 liter V6 engine.

I just replaced and gapped the plugs (Autolite), new plug wires, new coil pack, new air filter, new PCV valve, no vaacuum leaks, new fuel filter, but had a "flat spot" during acceleration. Checked the mass air flow sensor per the book and it is within specs. I do not have any "pinging". Engine does not use oil.

I added fuel injector cleaner-- the Chevron , (with the Techron in it) per bottle directions.

After 100 miles I noticed noticeable improvements-- got rid of the "flat spot" during acceleration and in general better acceleration-- till last night the "check engine " light came on.

Any other ideas???? What do I need to read the codes???

Thanks.

 

[swynx]

My 4.0 did the same thing I replaced alot! Fuel pump was a real improvement. 02 sensors helped too. Fuel pressure regulator was clogged after 300k miles. Tps iac maf ect all made a slight difference when I replaced them. As far as the codes there's a way you can check them without a tester. Just with some wire plugged into the testing port and a multimeter. I've done it. There's a right up some where.

If you go to the parts store they will test for codes for free

 

[snake]

It may be an OBD2 but most likely a OBD1. You can look under the dash on the driver's side for a connector port, they were switching a few over around 94-95. If its OBD1 look online for details on how to get to the codes, they will likely be flash codes. You may have a vacuum leak, low fuel pressure, or a dirty IAC but check the codes first to get some insight. BTW low fuel pressure or a dirty IAC won't throw a code...