2.7 bogging, backfires and bad idle !!

Hi all.
I have a 1997 model Taco with 2.7 3RZ-FE engine with automatic transmission.
She is driving me to distraction though.
Recently she has started running really badly. When setting off she will not pull away cleanly and instead bogs, coughs, backfires and nearly dies, then sets off like a rocket . If I have been using the engine for braking by downshifting descending hills she is even worse. Idling is awful starts off smooth but drops off and hunts and is like a roller coaster, the tacho needle jumping up and down. Compressions are all good, new plugs, new leads, rotor arm, dizzy cap cleaned idle control valve, all to no avail.
Can anyone help ?

 

Maybe check fuel pressure and have the injectors professionally cleaned.

 

Has anyone else had injector problems on the forum.
Thanks for the tip Speedytech.

 

I can say that I know of anyone with a 3rz that has had injectors probs, but some 5vz owners do. Simple maintenance always is a good place to start. Clean the throttle body, change PCV valve, check fuel pressure, make sure plugs are gapped properly.

 

I know it sounds stupid but I had really similar problem, change the plug wires

 

Im having a similar issue..but only after i wash it..weird

 

Isn't that a symptom of bad plugwires? Does it do the same when it rains heavily? I had a VW golf that ran like shit when it rained, changed the wires and then no problem.

 

Yea it gets the same way when it rains. Changed wires recently too because i read that too.

 

Well guys I have replaced the leads with NGK leads and she was no better so I took a mortgage and bought some oe leads and it was still no better. Cleaned AFM, IAC, no difference !!!

 

What about the distributor cap and rotor?

 

Cap and rotor replaces with oe parts.....

 

Might be time to start checking sensors (CAM, crank, TPS, temp, etc).

 

My 2001 was doing the same thing, Changed the coil packs and she runs like a champ now. Test your coil.

 

My truck has a coil built into the distributor I think. Has anybody else had problems with the distributor ?

 

Sort of a long shot here, but are you on the original cats? I had a crown vic that did exactly what your truck is doing. Turned out to be a clogged cat on the right side bank. It idled okay for the most part but under light load it would want to stall out, and it had no power at all. Here's what mine sounded like, skip to 15 seconds in https://www.youtube.com/watch?v=a3lJQ71Nld4 Before I found out it was the cat I replaced everything ignition related on the car, and I do mean everything. Also had the fuel rail pressure tested, new fuel filter, all sensors except for the left bank o2 sensor and MAP sensor, egr valve, etc. Over 750 bucks in parts and the problem was solved with a sawzall...

 

i had a similar issue with a dodge stratus. broke the cap and distributor during a tune up. ran like shit while I drove it to the mechanics. sounds a lot like your situation.

you have to have a code or 2 with that kind of behavior. which ones?

 

MAF sensor, plugs, wires are done, water in the fuel?, plugged cat, bad o2 sensor(s).....

 

nobody accidentally put diesel in there, right?

 

Hi Guys, fuel is good, cat good plugs and leads etc good MAF clean, original O2 sensors though. That could be my next port of call. I have owned her for 16 years and this is the first trouble I have had.

 

When on the freeway she will sit at 80 mph all day long !!!