Long-ish starts cold, too-quick starts warm.

[mckennar]

'98, 3.4l, injectors may be original to truck but can't verify.

Mornings, or whenever the engine has no heat in it, it takes about 2x as long as my other 4Runner to start. Which is to say, if it takes 3 cranks to start my other one, it takes 6 cold to start this one. I define a "crank" as a compression stroke that slows the starter motor as it turns. Let me know if this confuses anyone, I don't feel like I'm explaining it correctly but moving on...

Warm, even slightly warm, it starts on the first crank but it feels like it's only firing 2-3 cyl before the rest fire. Makes for a rough start for about 1/2 of a second if I let go of the key the second it catches.

Nobody else notices this but me when they're riding with me.

My gut and experience from other cars says leaking injector(s) or janky fuel pressure regulator. Anyone else seen this before?

I have decent power, getting 18-19mpg in mixed driving, idles tabletop smooth at 650rpm once warm.

Plugs and coils are 3000 miles old, as is the air filter and the fuel filter. No codes (stored or active), fuel pump is 3000 miles old as well.

Kinda stumped here. I haven't swapped injectors with the parts truck yet, but will probably be doing so in a few weekends.

Thanks.

 

[mckennar]

My TPS threw a code a few weeks ago. I reset it, but the code came back, the very next day (I thought it was a goner...).

So I replaced the TPS with a known good spare and adjusted the throttle cable the previous owner had over-tightened... and wouldn't you know it, my starts normalized.

My theory is that either the TPS or throttle cable or both were applying 5-10% too much throttle on all starts. Now it starts as quickly as my parts truck, with the same amount of cranks before fire both hot and cold.

600+ miles since the replacement and so far so good. No codes, normal starts hot and cold, smoother idle, smoother and more linear acceleration and throttle response, and ~0.4 MPG better fuel economy measured fill-up to fill-up.

TL;DR - it was the TPS and possibly also throttle cable too tight.

 

[CalBlackSheep]

TL;DR - it was the TPS and possibly also throttle cable too tight.

How tight is too tight? I'm only asking because I recently adjusted mine to take out the slop.


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[mckennar]

How tight is too tight?

No such thing. Oh, cars... right.

I don't have an official spec, but I removed the cable and let the throttle return spring do it's thing, reattached the cable and tightened so that it's still at it's "rest" point on the stopper, but just barely.

There's a little more slop in the pedal than there was before, but I'll take it over the alternative.

 

[CalBlackSheep]

No such thing. Oh, cars... right.

I don't have an official spec, but I removed the cable and let the throttle return spring do it's thing, reattached the cable and tightened so that it's still at it's "rest" point on the stopper, but just barely.

There's a little more slop in the pedal than there was before, but I'll take it over the alternative.

Ok thanks! That's were I have mine. It's touching the stopper but not enough to open the TB

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