ncsugrad2006

So, for any of you have read my other threads you know I just got done replacing a flexplate on my 4runner. I bought it already broke, so I have no experience with the truck prior to purchasing it.

I got everything back together ok and it started right up, but it is having a hesitation when you hit the gas. It's not AS bad when the engine is cold, but I didn't have time to let it cool back off to test if there was really a different today (it's at my parents house an hour away until I trust it enough to drive..)

I tried cleaning the MAF today, but used brake cleaner so I hope I didn't hurt anything.

I also had the coil packs/wires off when I was redoing the valve cover gaskets and didn't notice any issues. I'm thinking it couldn't hurt to throw new plugs and wires in it before I start digging into vacuum leaks or anything like that.

CEL was on yesterday, but I unhooked the battery today to see if after a fresh reset it would run any better (it didn't). I do not know which code was throwing the CEL. Is there a way to check codes without a scanner on these things?

Here's a video of it: I know I'm hitting the throttle quick, but anything that LOOKS like a delay in the video is probably what it looked like in real life. It's delayed as can be when I turn the throttle blade. I could put the throttle anywhere from half to full from inside the vehicle and it take 3 to 4 seconds to really start revving up, and have a tough time getting any higher around 3K

Thoughts? I'm going to buy plugs/wires tomorrow.

edit: When it was idling it ran smooth enough, but I felt like it was missing or something.. I'm not sure why, but it just didn't sound like it was firing on all cylinders. I also pulled the front timing cover to make sure the cam timing was right (it was)

[youtube]http://www.youtube.com/watch?v=mBdhZxDPy9s[/youtube]

Zpd426

Check your injectors and replace the fuel filter. My 2cents.

ncsugrad2006

What do you mean by check fuel injectors? What is there to check on them? Just that they're connected/opening or something else? Or can they be dirty or something?

etan

start with the plugs and wires. Visually, what kind of condition are they in? are the plugs burnt? do they smell like gas? etc.

ncsugrad2006

I didn't pull them today--not sure why that rather obvious source of the problem didn't come to mind until I started googling.

I'll get by there in the next day or two and check them out. Wires looked fine when I pulled them off to do valve cover gaskets, but I didn't pull any of the plugs so not sure how they looked. I doubt previous owner changed them in the last 45,000 miles that he owned the vehicle, though. So they're probably due regardless.

ncsugrad2006

Also I remember thinking it was running rich due to a fuel smell on Sunday, so it very well may be ignition related.

Jomoka

When I first got mine the PO had stuck on an over-oiled K&N and had fouled the MAF. The symptoms were a CEL (rich O2 sensor readings) and a pronounced hesitation. It's a 5 spd manual so the throttle hesitation was really annoying.

Cleaned the MAF, stuck a paper filter on, and it all cleared up. The oil hard burned into a little sooty 'jacket' for the hot wire, which made it react slowly. Give it a quick throttle blip, and it wouldn't see the extra air going by for a little bit, and during that time it would go lean.

ncsugrad2006

Cool. I bought new plugs/wires/plenum gaskets yesterday so I'll put all that in today and see what happens. The MAF looked really clean when I took it off Monday. Old plenum gaskets had some of the black stuff coming off of the metal, so they can't be sealing perfectly. I didn't have any new ones when I put it back together so I just used old ones to make sure it ran/drove before spending anymore money on it.

I know these plugs/wires are at least 45,000 miles old, and probably older than that, so they're due anyways. Thanks for the info!

ncsugrad2006

Put new plugs, wires and gaskets in this evening. Still hesitated

I decided what the heck, let's drive it anyways. Took it about 10 miles to get gas and it did great. Got back home and now no hesitation, so maybe it just needed to be ran some

Idling a little high, probably a vacuum leak somewhere but I'll figure that out this weekend. Tis fixed in in my mind anyways!

ncsugrad2006

Pic of the plugs--believe it was time to replace them. Two wires fell apart when I pulled them off too, so who knows if they were working correctly.

etan

glad to know something got better. for future reference... i've check plug WIRES by lightly spraying them with water in the dark and ran the engine. if you can see sparks your wires are bad with either pinholes or cracked insulation.

ncsugrad2006

Cool idea--will give it a shot next time (hopefully there isn't a next time? lol)

Nuthuts96

iTrader: (1)

didn't see this in time- but the plugs, as you can see, get so worn down the spark necessary to arc takes a lot of extra power and is thus slower. It acts like you put in the wrong gapped plugs.

Did you unhook your battery after replacing the plugs? This would reset the settings the ECU last used (with faulty info re: the worn plugs).

I lived with a sluggish acceleration pattern for about 6 months, and now know the error of my ways. Glad you got it worked out!

ncsugrad2006

I didn't reset after spark plugs, but did a day or two later when putting new battery terminals on. Have driven it a few hundred miles this weekend and so far so good!