Cold Start Help

Hi guys,

I have been chasing a cold start problem on my 2001 TRD Supercharged Tacoma. When it is cold below freezing it is hard to start. It will turn over without firing. If I put my foot on the gas it will start to fire but run rough for 15-30 seconds then runs fine. No other issues once it runs for about 30 seconds. Sometimes I get a CEL for random misfire p300. I had it into deal who took $2000 out of my wallet and didn't fix it.

I have done the following:

New maf
New a/f sensor
Cleaned tb and IAC
New 10mm plug wires
Tried different coils
New one way check valve from tb to engine
Urd fuel/maf calibrator and took it to a tune shop for set up
High flow aem fuel pump
Denso plugs - I have used ik25's and ik27's. I usually notice an improvement when I put in new plugs but it only lasts about 2 months and the problem comes back.
Sea foam treatments, injector cleaner, and running 91 or 94 fuel.

That is all I can think of now. I am at my whits end. Please any ideas.

 

move to Florida?


Since you've tried most of the fixes the one I didn't see is fuel filter?

Could also be the high-flow fuel pump is too much.


And worst case is the ECM, that's the last control item not already gone over

 

How do the plugs look? Sooty,or tan color?

You get 2 months of good starts on new plugs regardless of the outside temp?.

 

Hi Frizzman,

The truck did the same thing before I changed the fuel pump so I don't think that would be it. The fuel filter is fairly new maybe a couple years old. I don't have fuel issues during regular driving so I don't think that would be the problem but I could try a new one, it is a cheap easy fix.

 

Hi Mod,

The plugs are pretty white, which I believe is from the supercharger pushing alot of air in. My tune shop recommended cooler plugs and that is why I have gone with the Denso IK27's gapped at .043.

Yes with new plugs I will get better starts regardless of the weather. I just ordered a set of new plugs and a new IAC. Hopefully this will help.

How would I tell if the ECU is causing the problems?

 

Hi Guys,

I think I finally got it fixed! The culprit was the ECT sensor. Changed it last night and this morning, on cold start, it fired nice and smooth. It also is running smoother when driving. Hopefully that has it fixed. I have spent a pile chasing this propblem.

 

I also thought I should include the codes I got with this problem. I only got CEL lights for random misfire codes (P300; p302 etc.) I did not get a specific code for the ect sensor. After doing some internet searches this seems to be common. Another sympton was I was burning through plugs quite regularly (every 3 months). Talked to a mechanic friend who said that could be because the ECT sensor was causing the truck to run lean.

Truck still feels good but it has been warmer out. I will update if the cold start problem comes back when the outside temp drops again.

 

Good to know! I think my Camry may be due for a new ECT sensor...hmmm.