Engine Hesitation and Sputtering

I have a 2.4L with about 149K and my engine hesitates every 5-20 seconds only after It warms up.

The initial problem started one day while I was parking my truck when my engine just quit. After that I couldn't get it started at all. I had it towed to a mechanics shop, where they found the problem was a burnt ignition coil which in turn knocked out my igniter module. They replaced both, but it still would not start. I had an MSD ignition system which had to be taken off and it started right up. It didn't hesitate before it stopped working, but when I got it back it started hesitating. They went back over everything they had worked on and nothing was left undone. I Changed, cleaned, and replaced a lot of stuff, but still isn't running right.

I've changed plugs, wires, cleaned MAF and K&N Filter, replaced Ignition coil, Ignitor module, replaced TPS, Checked fuel system, everything is working, replaced PCV valve, O2's are working fine, and checked little things here and there. There's nothing wrong with CAT output either.

If anyone has a solution please tell me cuz it's driving me and my mechanic insane. Thanks

 

I have the exact same problem as you and almost the exact same milage (I'm currently at 147K). As you said, once it's warm it will hesitate every 10 seconds or so, and sometimes when accelerating at low RPMs I can feel it sputter.

Were you ever able to find a solution? I've already replaced the plugs, coils, cleaned the MAF and throttle body, and run Seafoam through the vacuum hose. No luck.

 

any CEL codes? Hows your fuel injectors? They may be dirty or clogged

 

Before I replaced the plugs and coils I was getting P0302 and P0352 codes. That's what got me started on this issue. Since then though there haven't been any codes.

I haven't looked into the fuel injectors yet. On my last tank of gas I ran a full can of seafoam through with the gas hoping that it would clean the injectors. That might have been wishful thinking...

 

does your year truck have a fuel filter? if you had some really cruddy gas somewhere it could be messed up your injectors even with the seafoam.

 

I'm not sure if it does, I don't have the Hynes manual in front of me. It's a 2006 2.7L 4-cyl manual. Is there a way that I can check if it has a fuel filter?

 

Mine has started hesitating more and now whether it is cold or warmed up. I just ordered an entire distributor since all this started after i replaced the original coil. Never replaced the distributor though so hopefully it may fix the problem. I've also run numerous kind of mild to concentrated fuel injector cleaner through the injectors but hasn't changed anything.

 

That's a bummer, I was hoping you had found an easy fix for it.

I'm fairly sure that my 2006 doesn't have a distributor, since it has individual coil packs. Not sure what to try next.

 

What's weird is that I don't have any CELs, but when I hook my tester up to it I get a p0401 code which has to do with EGR valve, which I already replaced and no change still.

 

the 2006 I believe has a fuel filter in the tank. From what I read.

 

There are probably 10 threads with people having the exact same issue as us. No confirmed solution in any of them.

There must be something other than the obvious going on here.

 

A clogged up or old fuel filter can cause poor running conditions

 

Aftermarket coils/distributors can be flaky. Try a cheap used Denso distributor from a junkyard if you can find one.

At least one person solved their similar problem with a used Denso distributor. Also a 1996.

https://www.tacomaworld.com/threads/2-7-stumbles-and-bucks-under-load-solved.449971/

 

That might be a good solution for mshane, but my 2.4L is a 2006 so no distributor :/

 

Well these sputtering/hesitation problems seem like a momentary lack of spark or change in spark angle advance, so anything that throws the computer's timing off could cause that like the cam or crank angle sensor. It could be other sensors but the cam/crank sensor's waveform is the type of signal that the computer could momentarily misread if the waveform is weak. I'm not saying throw parts at the problem, but keep an open mind and check everything.

 

I'm not sure how to check the cam/crank sensor output.

For reference, here is what I have done so far:
-New spark plugs (Denso)
-New coils (Denso)
-Cleaned MAF
-Cleaned throttle body
-Cleaned air filter
-Checked battery (12.7V and didn't drop below 11V while starting the engine)
-Cleaned battery terminals
-Cleaned all connectors that I could reach (sprayed them with the same MAF cleaner)
-Ran Seafoam through the gas tank and vacuum line

Current state of the problem:
-Starts and idles fine for maybe 10 minutes
-Once warm, the idle becomes rough and hesitates every 10 or 15 seconds
-Occasionally the engine sputters when accelerating at low RPMs

 

@mshane, I'm the guy from the thread Dr. Z mentioned. Do yourself a favor and find a junkyard OEM distributor. Takes no time to swap out and may save you a lot of trouble.

 

Same problem here with a 3.4 4x4 2001....I can't help but think this problem is fuel PUMP related? I see everyone has done the distributors and all "spark" issues and that doesn't seem to fix it. I cleaned my MAF, replaced my O2 sensor and fuel filter. No luck.

 

This is all sounding like where I was 6 months ago, Issue would come and go with no codes. 2 weeks ago started a No Cold Start when not level then went to No Start after changing fuel filter and throwing P115.
I just fixed the PO115 issue today which was the Coolant Temp, Sensor. Will post up in a few days as to weather or not the hesitation issue is resolved, but after studying that sensor's function; it could well be.

 

Did this help? I’m currently in the same situation