main relay or fuel issue?

laur19 · 10-14-2008, 11:59 PM

'01 Kia Rio ~ hey I am having LOADS of trouble with my car one issue after the next....I have recently replaced the fuel filter, spark plugs, brakes, brake lines, entire ignition system, battery, fuel filter, and alternator belt. I have been told by my mechanic that the alternator, starter, water pump, and fuel pump are in good condition. Yet after only having the ignition system replaced less than a week ago, my car is not starting all the time!!

We purchased a code machine and scanned and got a code P1640 (DOES ANYONE KNOW THIS CODE??) It says "replace main relay" anyone purchase one or know what they go for? Please answer my question, my car repairs are soon going to outway the actual value!! Thanks!!

ron1004 · 10-15-2008, 02:48 AM

Welcome to the forum.

It sounds like a lot a replacing has been done without good diagnostics.

The Main Relay is in the Fuse/Relay box in the engine compartment - most auto parts stores should be able to sell a replacement.

laur19 · 10-15-2008, 09:10 PM

hey, thanks for the quick reply, that site helped a lot, but I checked ALL fuses inside the engine compartment and inside the drivers side of the vehicle. they all seem fine. Still lots of starting troubles. Never starts after car is off for long periods of time. If I get it started and turn it off then it always starts right after. It's just getting that first start. Sometimes if I take the key out and put it back in then it starts....but it's not the ignition system coz I just had it replaced. Any other things it could be??? IT'S VERY FRUSTRATING!!! thanks

ESKORT27 · 10-15-2008, 10:14 PM

sounds to me like a fuel pump issue, sounds like fuel presure is bleeding off after it sits for a while and it takes a while to start because the pump has to rebuild the pressure needed. It hook up a fuel pressure tester after it has been sitting for a while then while watching the guage, turn the key on and see what your pressure is. Just a suggestion im a kia tech and i have seen it a few times before.

ESKORT27 · 10-15-2008, 10:19 PM

also i researched the code you have and it sounds like a faulty battery or a draw on the system or an over charging alternator.