Rough idle, stalling, wild STFT, p0171, 2RZ-FE and headaches

A cursory look at eBay didn't turn up anything for a delete kit or bypass kit, but a new EGR looks like roughly $100-$140.

 

rockauto? make a delete. not hard lol.

 

Nice, I actually believe I have a block plate for the manifold side of the tube already. I could finagle something for the intake side of the tube.

What about the vacuum line between the EGR and the vacuum modulator?

 

couple of caps?

 

That's what I was thinking. Thanks for verifying. I can probably 3D print something to do the job; a plug or something.

 

Welp, today I installed a delete kit for the EGR system that I cut out out of some 1/8" steel plates. I used appropriate gaskets on the exhaust manifold and the intake manifold for each end of the EGR tube. I capped off the EGR vacuum line to the vacuum modulator using 3D printed caps and a little hot glue.

Started the truck, backed it out of my driveway and went for a drive. With 60 seconds, I could hold the gas pedal to the floor and the engine would only sputter, just as before. It even died once. I restarted it and was able to work up to 40mph or so and drove it back around the block and parked it.

The fuel mixture is still coming out super rich.

So far I've replaced the MAF, the cat-con, both o2 sensors, all vacuum lines, and removed the EGR.

I'm beginning to think that Seafoam may have clogged one of my new injectors, so I guess I'll take the fuel rail off tomorrow night and clean the injectors.

After reading through another thread about the mixture running rich, I'm starting to believe that Seafoaming it through the intake may have caused some real issues in the fuel management system.

 

Check the fuel pump pressure. I still think this shit is related to that man. You have ruled out damn near everything else. Hell have you checked the compression and timing of the engine?

 

Loosening the bolts on the bed, raising it, and changing the fuel pump was my next maneuver. I have a new pump laying in my parts bin that I just haven't bothered to install yet.

I don't have the tools to perform a compression test, but I can tell by the presence of gasket material that the previous owner at least had the head off at one point, so who knows. The previous owner purchased an engine rebuild kit and gave it to me with the purchase of the truck. I have 4 new pistons, seals, water pump, oil pump, timing kit, head bolts, and some other miscellaneous engine parts. I'm just not brave enough to start putting them all on.

I guess I'll have to bite the bullet and get a mechanic to do a compression test.

 

Harbor freight tester is like 25. Not the greatest by any means but will work in a pinch. Worth pulling the valve cover and checking the timing on cam gear, crank pulley and stick an extension in cylinder one to verify top dead center

 

I was just browsing Harbor Freight to see if they had a cheap one. I can spare $25 to have a compression tester in my tool box.

I'm comfortable pulling the valve cover and checking the timings and TDC. Thanks for all of your help and advice on this.

 

Np dude. I'm not the best tech by a long shot. I'm a Toyota lifer after my old Lexus LS400 and now this truck. TacomaWorld has been damn good to me and I try to pass the good forward in some way.

Also this issue has me frustrated as well. I wanna solve this mystery haha

 

I appreciate it. I'm a lifer, too. Everyone told me how well this truck was going to do and how much a little TLC would improve it. Now I'm committed to figuring it out, otherwise it's money pissed into the wind.

 

Are the O2 sensors the correct ones? It seems I remember reading that at some certain year they switched from the air/fuel sensor to an O2 sensor. Might only apply to certain engines as well. Also Cali spec emissions tacos I think might've had a different sensor. I could be way off, couldn't hurt to double check.

 

Hi Iamtheghost,
Any history on this event? Like how long ago was it when it was running just fine? And how old is the gas in the tank?
Ken

 

The suggestion that the cat was causing this issue was one of the more bad suggestions I've heard in a while. A plugged cat will usually cause loss of power or a misfire at higher RPM's. He has poor fuel trims at idle which clean up at higher RPM from my understanding at least.

OP, What brand MAF did you replace your OE one with? Please don't say the Duralast or O'Reilly brands.

If you have doubts about the EGR, remove it and see if the engine will stop running like crap. Another way to test it is to have someone rev the engine while you feel the diaphragm for movement at different RPM's, if it moves, the EGR is operating correctly.

 

Just read the second page. OP if you want my advice check your timing belt as previously suggested, if that checks out fine then take it to a shop and have them check for vacuum leaks using a low pressure smoke test, check fuel pressure, compression, and perform a cylinder leakage test. By replacing stuff unnecessarily you are costing yourself more money and time (also headaches) in the long run than by just taking it to a shop for a proper diagnostic with proper tools made for the job. I can respect the backyard mechanic attempts, but this issue may be something that is over your head.

 

How was the cat a bad suggestion? Genuinely curious. I told him to disconnect it from the flange to rule it out. If nothing changed then put it back together. I came back to thread and he had replaced it lol.

 

I'm sorry about that. I didn't read the part that suggested checking it. I was under the impression you told him to replace it. Idk why he is dropping stupid money without just ruling it out first or getting it professionally inspected. Like I was telling him it only ends up costing him more in the end.

 

After OP verifies fuel pressure at pump, rail/injectors - checks the timing - and finally the compression, im out of ideas. At that point tow it to a shop and pay the $100 diag fee to figure out exactly what in the fuck is going on

 

That's how I feel about it as well. If he does not have the tools or resources we are all just taking shots in the dark without having the vehicle in front of us.