Rough idle and stall on startup

[John Howard]

I'm having an idle issue with my 95 L4 GL model. It's always idled rough but now It's not starting too good either. Wants to repeatedly stall on startup. I've looked for vacuum leaks with no luck, replaced the Idle Air Control Valve, ignition wires, cleaned the intake manifold, replaced the Mass Airflow Sensor, etc. Now I'm thinking about replacing the fuel cannister solenoid as I hear a humming sound come out of the fuel tank area when I shut off the car and park it. No codes at all show up. Any tips or ideas? Thanks!

 

[SVTWHAT]

do you ever run fuel system cleaner through it?

 

[John Howard]

do you ever run fuel system cleaner through it?

Yes, ran cleaners through it more than once. No change. First I'm going to check for vacuum leaks again. The hoses are all 1995 original. Then I'm thinking purge valve solenoid or EGR valve. Hate to just throw more parts at it.

Couple questions. Is it normal to have some pressure in the gas tank when you release the cap at the gas station? Is a humming sound coming from the fuel tank area when the car is sitting and not running a normal thing or a sign of a problem?

 

[John Howard]

A few more details about my '95 Contour's problem.

It's idled rough, lopy and too low since I got it in 2003 but started good and rarely if ever killed at stop signs. Sometimes I'd put it into neutral and that helped. Lately, however, it's gotten worse. The other day I drove it 30 highway miles at 55 mph then had to quickly restart it while hot 2-3 times at a store loading dock. Neither time did it want to restart easily, but started then died or fired a little but wouldn't catch, like 2-3 times. After a few attempts it finally did catch and I revved it up and drove it home perfectly fine. At home it instantly restarted. I've already thrown parts at it without success, but this time I'm determined to fix it or die trying. Any tips or suggestions welcome. My first notion is a vacuum leak, although I could not find any in the past.

 

[John Howard]

Even though a faulty EGR or purge valve solenoid is supposed to throw a code (1995/OBD-1), if there is no code present might those parts still be bad and causing rough idle and hard starting?

 

[John Howard]

I know I'm the only guy in the world still driving a 1995 GL, but I don't care if nobody's listening...

I pulled the plastic airbox and visually inspected all vacuum lines. All looked good. I did notice that the plastic insulation had fallen off my fuel injector and fan wires so they are now bare copper! Then I cleaned the throttle body again with the correct spray on a toothbrush and only sprayed a littled directly in. Put everything back together and the car wouldn't start! Let it sit overnight. Nothing. Fired a little with starting fluid but it wouldn't catch. WTF? So I poured raw gas into the TB and then it did start. I let it run. It also then restarted. Seemed to actually idle a little better too. Time will tell.

The no start condition might have been caused by the TB cleaner, but I also noticed this. When turning the key to "on" the fuel pump did not run every single time like I believe it should. I also noticed that same thing when it wouldn't start the other day out of town. So maybe that was part of the hard starting trouble in addition to the TB cleaner -- or maybe not. Anyway, I swapped the horn and fuel pump relays as they are the same. Relays are original 1995 with 180,000 miles. Will order a new one. Also paint those naked wires with Liquid Electrical Tape.

At this point I'm not doing anything else but will just see how well it starts and runs. It's still a solid car with zero rust and I hate to give up on it. Plus the auto transmission still shifts like a dream! But it is a Ford and not a Toyota.

 

[ruwfo]

fuel pump did not run every single time like I believe it should...

Yes.. you should hear it (fuel pump whine) every time you turn the key, past "on" position. Before my Ranger's fuel pump
went completely a year later, i 'd turn the key past on, but not to start, before i started it, & it helped my starting problems.

Have you replaced the DPFE sensor/module, & the vacuum hoses to it, it's common problem on Ford's. It will kick off
a code, when it's goes, but maybe yours it's total shot yet.

Also use Lucas fuel injector/top end cleaner, best stuff i've every used, pour it right into gas tank.

 

[John Howard]

fuel pump did not run every single time like I believe it should...

Yes.. you should hear it (fuel pump whine) every time you turn the key, past "on" position. Before my Ranger's fuel pump
went completely a year later, i 'd turn the key past on, but not to start, before i started it, & it helped my starting problems.

Have you replaced the DPFE sensor/module, & the vacuum hoses to it, it's common problem on Ford's. It will kick off
a code, when it's goes, but maybe yours it's total shot yet.

Also use Lucas fuel injector/top end cleaner, best stuff i've every used, pour it right into gas tank.

Thanks for the rely.

I think my intermittent no start condition was due to a failing fuel pump relay. Since replacing it ($10) the fuel pump turns on every time and the car starts every time too.

I was thinking that the bad idle was connected to the no start condition, but now I believe they were separate problems. No, I haven't changed the DPFE sensor but I shall look into that. No codes are being thrown. After cleaning the throttle body (third time) it seems to idle a little better, but still too low. Fixing the bare (crossed?) Fuel injector wires did nothing.

I still have some Techron cleaner to run through it. When that's gone I'll try Lucas. Can't hurt. Other than the low idle, it runs good.

 

[ruwfo]

Since replacing it ($10) the fuel pump turns on every time and the car starts every time too.

Good catch