Idles Rough & Gets TOO low also Engine not starting

[Mr.Ford]

Back to the basics

Well i thought the idle was fixed but i guess i was wrong. I bought a new iac and that didnt work. im lost im wondering if it is something with the egr sys. My friends dad had a 97 chevy and the idle was bad. He got codes pulled and it was code 32. He changed the egr valve. Well i got mine pulled and it was #327 EGR(EVP) Circuit Below Minimum voltage requirement. Does anyone no exactly what that means. I am so short on cash now that i got that IAC. And i cant return it. It is American and this stuff aint gettin no cheaper.

 

[dogfriend]

Your 327 code means that the PCM is seeing a voltage lower than expected from the EGR feedback signal. This could be because:

1) the EVR sensor is bad

2) the wiring is bad

3) the reference voltage (VPWR) is too low to begin with

Based on your description of the lights dimming, I would check your battery voltage first. If it is too low, it might be causing the 327 code.

I am sorry that the IAC did not help your idling problem. When I had the same problem, my IAC was sticking and not allowing the truck to idle. Your symptoms sounded like what I experienced, but apparently that is not the problem with your truck.

 

[BLKDIMND]

I have had this problem for a year now and it is becoming serious it caused me to lose my job because i was late. Perfect Timing

Here are my problems

1) When in reverse or drive(not moving), engine idles at 500-600rpm very unstably, sometimes it stalls out.

2) When engine is hot and has been turned on/off,on/off,on/off. It doesnt want to start. It will attempt to start but it will sputter and act as if theres no gas.(Also i noticed the fuel pump wont prime for some reason when this does happen).

3) I noticed when the idle gets low to 500-600rpm the battery meter goes to low or middle normal. This is annoying because all lights dim and the a/c doesnt kick out as strong.

4)I thought about pressure in the fuel pump and maybe it cant hold pressure. So one day it wouldnt start so i toke the gas cap of and put it back on. The fuel pump primed and the engine started but this did not solve the low idle problem and i dont think it solve the fuel pump problem either.

In the summer is when i had the problem. I cleaned the fuel injector with Gumout and it ran fine for a month. After that its never ran good since.

So far what ive done to fix the problem is

1)Replaced the fuel filter - No Change
2)Fuel Injector Cleaner - No Change
3)Cleaned IAC - No Change
4)Replaced EGR Valve Pressure Sensor - No Change

I also got some codes ran, the check engine light WAS NOT on. Im an engineering student and i know you can get codes ran even if your check engine light isnt on.

1) EGR(EVP) - Circuit Below Minimum Voltage Requirement-Sonic(PFE)

Its beginning to get expensive and im running out of solutions. I was told it could possibly be the fuel pump if it is I want to make sure because a fuel pump is not cheap or that easy to get to. Please i need help!!!

ypur proplem is one of your oxegen sensors on the exhaust,i had the same prob and changed them and magic now it runs like new

 

[Mr.Ford]

Does anybody have anymore suggestions. I got another iac and its been 1 day and my idle is ok. But if it goes low again i will let you know. But in the mean time does anybody have any pictures of the vaccum lines. Because i hope im not missing anything. I think i hear this hissing noise sometimes.

 

[Mr.Ford]

Iac works great, idle holds with all accessories on. But everyonce in awhile i get a problem to were i dont here the fuel pump prime anymore and the engine wont start, so i turn the ignition sometimes until i here it prime again. It seem to happen when its hot out. But the idle is never a problem. Anybody got any ideas.

 

[dogfriend]

There is a PCM power relay and a Fuel Pump relay. The PCM power relay provides power to the Fuel Pump relay (and also to the PCM).

You should check both of these relays to make sure you are getting power to the fuel pump.

The other possible issue could be that the check valve in the fuel pump is not holding pressure. You can diagnose this by testing the fuel pressure after the key is turned off. It is supposed to hold the pressure for a certain amount of time after the key is off.

 

[Mr.Ford]

Update

Well for a week i thought everything was good. But the idle is worse then ever before. I dont know what to do. I am so close to gettin rid of this vehicle, i love it. It has perfect interior and the body is good except for the rust around the gas cap(minor Fix). But if i cant fix it and im am already over budget, its gotta go. Chevy tahoe is lookin nice right now.lol. Please, does anybody know what all the parts are that control the idle speed on a 94 Ford Explorer 4x4.