cold starting problem

[JohnKarlsson]

Hi guys this is my first post here.But I cant seem to find a solution to my problem.
Ok here goes

I have a 98 v6 4runner 275k on it
I has been very reliable but I think things are starting to go on it.
We had the fuel pump replace about a year ago.
Now with the colder weather-10c we are having problems starting the engine.
It will crank and crank then sputter and die.eventually we can get it to start.Once it is going it runs like there is no problem at all.we can go to the store and come out 2 min later and have the same problem.any idea what to start looking for?
any help would be great
Thanks
John

 

[JohnKarlsson]

I would like to add that when it is cold from over night it starts fine.But after you have driven it it it wont start.

 

[jgue467]

Has MAF and general intake been cleaned? Last 'tune-up'? Do you run an ethanol/intake/carbon cleaner in fuel regularly, like say seafoam or startron? If not I'd try one of those first, i like the latter, it may help quite a bit alone. Luck!

 

[soundmanlpte]

Agreed. Use a fuel cleaner. Clean intake and MAF. Have battery and alternator checked. After those things I would suggest rebuilding starter and replacing starter contacts. It's cheap if you do it yourself. Rebuild kit $15. New starter $60.

 

[JohnKarlsson]

I have used seafoam about 6 months ago.
When the temprature is warmer outside the problem goes away.So I feel that it is somthing to do with the cold air.
but why does it start when the engine is cold but not when it is warm?:mmph:

 

[Supermoney]

If its cranking then it shouldn't be the starter contacts. If it was it would just click.

 

[soundmanlpte]

I have used seafoam about 6 months ago.
When the temprature is warmer outside the problem goes away.So I feel that it is somthing to do with the cold air.
but why does it start when the engine is cold but not when it is warm?:mmph:

Have you checked the battery's cold cranking amps and the alternator voltage?

 

[davidch]

A friend recently had an experience similar to yours. It was on a '96 Tacoma. (3.4 V6, 5 speed) He had purchased the truck in July with about 150k on it. The previous owner said the fuel pump had been replaced twice. That's rather odd, I thought at the time.

The truck ran fine until early October. Then it became very difficult to restart, though it did fire up easily each morning. Once running, it sputtered if under acceleration.

I agreed to look into it. Long story short: the "mechanic" who'd installed the most recent fuel pump had done the job badly and with an improper strainer.

When I dropped the tank, I found the fuel strainer loose in the tank, and that strainer was not the correct Denso strainer. It was an odd 3-piece affair. I could not determine if the pump itself had actually been replaced. However, conventional fuel line - the stuff with a braided coating, a no-no inside the tank - was used, as were conventional hose clamps. (a lesser issue, but still it's incorrect.)

I dissected the pump (using a hacksaw and an exhaust pipe cutter as my scalpels) and found evidence on the brushes that the pump had really been straining. Furthermore, the impeller showed signs of scarring. With the strainer loose, the pump had ingested a bit of crud, possible the little clip that was supposed to attach the strainer. Or small pebble. It doesn't matter; the strainer is there to prevent this.

My thinking is that first thing in the morning, the pump could somehow get up enough pressure to start the truck. During the day, subsequent starting somehow demanded more than the pump could deliver. Maybe whatever was scarring the impeller was in such a way that the pump was jammed. Overnight, things relaxed and it temporarily unjammed. Or when it did restart, warm, after a series of attempts, it was the pump temporarily freeing up. Eventually, this pump jammed completely and popped its fuse. (There's a really long story behind that...) As I wrote above, the brushes showed signs of a motor that had gotten hot.

So, I ask if your pump and strainer were replaced correctly with Denso items? Have you performed the 3-step test of the pump as explained in the factory shop manual?

 

[JohnKarlsson]

I had the pump replaced at the mechanic shop.It just seems odd to me that it would go so fast.thats why I was asking if there is possably some thing else that might cause this.my mechanici is under the school of "that if it aint broke dont fix it".
But intermitant problems are worse than full blown repair jobs.

 

[Jon]

Try the IAC (Idle Air Control) Valve:

It's the air bypass used for idle while there is no throttle applied and the throttle body is completely closed. It is a rotating valve that is spring loaded and can get stuck over time but is very simple to clean.

I clean mine around every 10k miles or every other oil change.

Time: 20min

Tools: 10mm or philips screw driver, deep 12mm socket and ratchet and pliers

Consumables: throttle body / air cleaner and a spray lube such as PB-Blaster or WD-40

ONLY PERFORM ON COOL ENGINE!

1. Remove the intake pipe between the throttle body and the intake box ( 2 x 10mm or phillips head bolt clamps)

2. You will loose a minor amount of coolant on this step... AGAIN, ONLY ON COOL ENGINE unless you like hot green water in your face.. using pliers, slide back both coolant line clamps then twist lines to loosen an remove from t-body.

3. Remove t-body linkage wires by opening the valve by hand an removing wire end. Requires 14mm open wrench

4. Remove 2 x 12mm nuts and 2x 12mm bolts securing t-bod to intake.

5. May need to unplug #3 coil wire (it is the one in the way for the next step)

6. Last vacuum line is on the bottom and should slip off easily as you pull the t-body towards the passenger side.

7. Once the t-body is removed, you can now remove the coolant bypass cover exposing the IAC valve.

8. Remove 4 x large philips screw from bottom of t-body.

This will allow you to remove the small plenum that the coolant lines were attached to. And under it you will find the IAC valve. This will allow you to actuate the valve by finger. If you are this far into reading, it is probably slow and sticky. Spray a bunch of TB-cleaner at it and actuate it a bunch. There is no magical formula here. When it feels like it has a nice "pop" when you trigger it I'd say we can move to step 9, or whatever we're on here.

9. Give a a quick squirt of PB-Blaster to keep it lubed

10. Re-assemble in reverse order using factory torque specs.

If there is an excessive build up of oil in the intake, this would also be a good time to replace the PCV valve.

Every time I notice a low idle at start I rip this apart real quick and I find this is the culprit. I've probably had this off a dozen times but I wheel this thing hard so no surprise.

 

[soundmanlpte]

You still haven't said if you've checked the electrical... Batteries hate the cold. I had to replace a battery on a Chevy van when traveling through Wisconsin during the winter. It still had about 400 cold cranking amps, but it needed more like 700 to withstand the cold and startup every time. I know it seems unlikely based on your symptoms, but it's free to check the battery and alternator at an auto parts store.