Car Maint Help

[Hooknswoop 19]

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Check the vacuum hoses. A leaky vacuum hose can cause that since it allows air to bypass the mass flow sensor. It's worst at idle since that's when vacuum is highest, and that's when just a little leaking air can confuse the computer. And since most cars use vacuum to drive the A/C control valves and the brake booster, those vacuum hoses go all over.

I have replaced some of them. What makes this hard is it goes away for a while. I can walk out and it starts up and runs completely normal. Other times it throws a fit, then runs normal. This is driving me nuts.

Derek

[chutem 0]

If it is fuel injected it might also be a fuel pressure problem, the injectors stay open a certain amount of time and if the fuel pressure is not what it should be,enough fuel will not squirt out. A motor needs more fuel when it is cold thus no start or start and run poor till warmed up. On most all but very sophisticated auto fuel systems the computer does not have a sensor to tell it the fuel pressure, it assumes it is correct. Sometimes slightly low fuel pressure will only cause very slight driveability issues, unless you are hauling a heavy load you may not even notice. On most injected vehicles it is not to hard to check the fuel pressure, and as mentioned before filters are cheap. I'm not saying this is the problem for you or the other poster just don't ignore this important check or you could end up putting alot of time/money/frustration into replaceing other parts with "shotgun" troubleshooting.
James

[Hooknswoop 19]

Ya, fuel filter is on the list.

Derek

[chutem 0]

Many electric pumps get weak before dieing, also on my van the check engine light was not comeing on when the computer screwed me. It was just intermitant driveability problems. My computer was way over $140 also.
James

[chutem 0]

Throttle Position Sensor could also be the culprit, most can be checked with a volt/ohm meter.
James

[skycat 0]

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Sell it and buy a Chevy!!!

Naaa..he can have my Mazda 6 so I can get an RX8.

Fly it like you stole it!

[AggieDave 6]

What was the condition of the spark plugs you pulled out, did it show a less then ideal condition (besides being worn)?

Do you have any water/coolant in your oil?

Just some things that I didn't see mentioned to check.

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[mjosparky 4]

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Check the vacuum hoses. A leaky vacuum hose can cause that since it allows air to bypass the mass flow sensor. It's worst at idle since that's when vacuum is highest, and that's when just a little leaking air can confuse the computer. And since most cars use vacuum to drive the A/C control valves and the brake booster, those vacuum hoses go all over.

That would be my guess. It can take quite awhile to check them all out.

Sparky

My idea of a fair fight is clubbing baby seals

[hookitt 1]

Does it change when you push on the brakes? Put it in park, push on the brakes, if it changes, check the hose, and the vacuum booster.

Pull the hose from the booster and plug it. See what happens.

http://auto.howstuffworks.com/power-brake1.htm

My grammar sometimes resembles that of magnetic refrigerator poetry... Ghetto

[diablopilot 2]

Fuel supply and pressure have been checked and ok.

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You're not as good as you think you are. Seriously.

[Spizzzarko 0]

Air temp sensors. Some cars use them to meter the fuel air mixture. If one is bad then your computer may be running the car to lean or to rich. I just ran into the same problem on my old Saturn (Good running vehicle by the way).

[Hooknswoop 19]

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Throttle Position Sensor could also be the culprit, most can be checked with a volt/ohm meter.

Checked it, it was bad, replaced it, didn't fix the problem.

Derek

[Hooknswoop 19]

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What was the condition of the spark plugs you pulled out, did it show a less then ideal condition (besides being worn)?

Plugs were OK, but old. I waited too long to replace them. With 2 plugs/cyl, I got lazy. No oil/coolant mixing.

Derek

[Hooknswoop 19]

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That would be my guess. It can take quite awhile to check them all out.

Would a vacuum leak explain the surging/dieing to idle with the throttle wide open 3-8 times, then running normally from idle on up?

Derek

[Hooknswoop 19]

OK, replaced the Idle Air Control Valve. Didn't fix it. Replaced the Fuel Filter and drove it for 1-mile stop and go, trying to get it to screw up again, no problems so far. I won't know for sure since it has run fine for miles at a time without a problem. I'll know for sure in a day or two.

Thanks to everyone for their help. Hopefully it is fixed.

Derek

[skiskyrock 0]

It sounds like the classic symptoms for an idle air controller failure. My '94 probe used to do this every couple of years. This won't do you much good since you bought a new one (the Probe version was very expensive and hard to find), but they can be cleaned. The warning label that says not to use solvents is mostly BS. There is a thermowax cold start thingamabob that can be damaged by solvents, but if you take the IAC completely out of the car, it is pretty easy to see what needs to be cleaned without hosing everything down with Gumout.

[Hooknswoop 19]

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It sounds like the classic symptoms for an idle air controller failure. My '94 probe used to do this every couple of years. This won't do you much good since you bought a new one (the Probe version was very expensive and hard to find), but they can be cleaned. The warning label that says not to use solvents is mostly BS. There is a thermowax cold start thingamabob that can be damaged by solvents, but if you take the IAC completely out of the car, it is pretty easy to see what needs to be cleaned without hosing everything down with Gumout.

Ya, I tried that a while back, pulled it off, cleaned it up, and put it back on. Didn't change anything. I don't think it was broken in the first place.

Derek

[Hooknswoop 19]

I have replaced:

Spark Plugs and Spark Plug Wires
Mass Air Flow Sensor
Throttle Position Sensor
Oil/Oil Filter
EGR Valve
2x O2 Sensors
Purge Valve Canister Solenoid and Switch Assembly
Air Filter
Fuel Filter
Idle Air Control Valve

Checked the PCV valve, it's OK

Still not fixed.

Things to check:

Timing
Vacuum (not sure how I am going to do that. I looked at the vacuum lines and they all seem good. I pulled the vacuum line off the EGR Valve and put my finger over the end and it had vacuum.)
EGR Vacuum Regulator Solenoid
Engine Coolent Temperature Sensor
Air Intake Temperature Sensor
PCM Computer

Derek

[Vectracide 0]

Sounds like a cold start sensor. It adjusts the choke depending on engine temp. If its cold out and its not kickin in the choke enough, or at all, it will start hard.

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Controlled and Deliberate.....

[Keith 0]

I had the same problem with my '98 Ranger. It was the mass air flow sensor though.

Keith

Don't Fuck with me Keith - J. Mandeville

[diablopilot 2]

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Sounds like a cold start sensor. It adjusts the choke depending on engine temp. If its cold out and its not kickin in the choke enough, or at all, it will start hard.

Really? On a FI vehicle with MPI?

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You're not as good as you think you are. Seriously.

[Derekbox 0]

I have a 92 Ranger. VERY similar problem. It turns out it was a compression/valve issue. I had worked through a few of the same things you did. What ended up fixing it was a $6 can of "Restore: restore engine restorer and lubricant" I dont normally invest in snakeoils but someone at work recommended it - and Ill be damned it worked. Helps reseal valves and piston rings.

My problem got progressively worse to the point where it missed all the way through the throttle range. It started as an occasional hiccup and made its way to being a constant pain in the ass.

I dont know if it is your problem. Here is something to check - on the aft of the engine, driver side, under the manifoldish area is a vaccum hose that easily can get knocked loose working on your car.

Good luck - tell us what works.

[Hooknswoop 19]

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I had the same problem with my '98 Ranger. It was the mass air flow sensor though.

Did your check engine light come on? I got a code for that not too long ago and already replaced it anyway.

Derek

[scotts 0]

The easiest thing to do is take a spray bottle of water and while the vehicle is running, spray the coil, distributor cap, plug wires (especially at night) and any other electrical gizmo you can find and see if there is a noticible change.

Could also be ignition control module. If you haven't had diagnostic codes checked yet, go to Advanced Auto, Autozone, Pepboys or whoever is in your area and let them check them for you. This can be done on or off the vehicle.

Your TPS is adjustable, so if you didn't mark where the old one was set and the new one didn't go in exactly the same place, it could be out of adjustment. You can find out alot more info at Ford-Trucks.com.

I have dealt with the same problems on more than one ford, so hopefully this can be of help.

P.S.
The amount of info that you post here is unbelievable to say the least. Not to paraphrase, but, " I wonder how many incidents from gear/safety issues have been avoided thanks to HOOKNSWOOP".

Thanks!

[Hooknswoop 19]

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The easiest thing to do is take a spray bottle of water and while the vehicle is running, spray the coil, distributor cap, plug wires (especially at night) and any other electrical gizmo you can find and see if there is a noticible change.

No distrubutor, electronic ignition, so it's not the timing.

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Could also be ignition control module. If you haven't had diagnostic codes checked yet, go to Advanced Auto, Autozone, Pepboys or whoever is in your area and let them check them for you. This can be done on or off the vehicle.

Already checked, no codes.

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Your TPS is adjustable, so if you didn't mark where the old one was set and the new one didn't go in exactly the same place, it could be out of adjustment. You can find out alot more info at Ford-Trucks.com.

It is set right. There was no change before to after the TPS was replaced.

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I have dealt with the same problems on more than one ford, so hopefully this can be of help.

I'll try Ford-Trucks.com. I got a tip to re-set the PCM. I'm also going to go loking for a vacuum leak with carb cleaner or something. I figure the Mystery oil and restore can't hurt and are cheap, so I'll try those too. I was also thinking the coolant temp sensor. I really think the EGR vavle is opening when it shouldn't sometimes.

Derek