3.0 Stuttering
 

Ok so I have an 89 toyota with a 3.0 V6 5 speed and around 145k miles. Ive had the truck about 6 months or so and have done my fair share of replacing parts already. I did plugs, wires, fuel filter, new cold air intake, new magnaflow cat, new magnaflow muffler, changed all fluids and running lucas fuel treatment.

Now for the problem.....yesterday I was cruising home and when I merged to get off the interstate I eased off the pedal....slight backfire....which I havent heard since I replaced the exhaust. Almost immediately the truck starts stuttering. Once I get to 2nd 3rd and 4th gear it bucks and stutters the whole time. When I got home I checked under the hood to find the the plastic clamps that came with my CAI were cracked and it was sucking in air so I replaced them with new rubber clamps. Drove it down the street and its still stuttering. Im stumped.....any help is much appreciated!

Have you checked for any stored codes?

Ill be doing that today when I get off work. Ill update this with what I find out.

Im hoping like heck that its not something major.

Just check for the usual suspects vacuum leak, loose wire, etc etc.
IMHO the CAI sounds like a crappy one with those plastic clamps.
I would think after while the heat would takes it's toll on them anyway.
Stock set up works better for me. From what I read CAI's just take in the hot air from engine bay and no real gain in HP or gas mileage. Post up on findings.

Make sure all your spark plug boots are securely "clicked" onto the plugs. mine started doing that same think and it turned out it my spark plug boot was too long and just needed a trim cause it kept pushing itself back off the plug.

Yeah... unless you are drawing in actual cold air from outside the engine bay, that mod is doing very little for you... sorry bro. I noticed more throttle response by just putting some holes in the bottom of the air box, putting in a K&N high performance air filter and taking off the spoiler that sits behind the driver's side headlight. Cost me $45 for the filter (lasts forever) and nothing for the mod.

Stuttering could be a plethora of things. Anywhere from a vacuum leak, bad sensor, poor fuel pressure/blockage, or just some plastic clips breaking! Let us know if you get a code.

Ill make sure and check all my wires this evening....thanks for the advice.

Ive heard this before about the CAI....may be time to hit the junkyard for a stock air box and just drill some holes like you said. I love the sound of a loud intake but not at this expense. Ill let you know asap what I find.

Ok so I checked the trouble codes and this is what I got. Blinked 4 times then 3 times.....blinked 5 times then 1 time. ????

code 43 starter signal
code 51 switch signal

good luck

according to the factory service manual the likely suspects for hesitation in acceleration are:throttle position sensor, air flow meter, engine coolant temp sensor, intake air temp sensor

for surging, it says likely suspects: fuel pump, fuel filter, fuel lines,

good luck

So what does that mean....never had these codes before.

Starter signal is the signal wire from your starter to your Iginition. Switch signal is your ignition switch signal wire in your ignition i think. Those codes i think would just mean to check the wires that go to your starter and ignition. Correct me if im wrong guys

It means buy or download a manual :D

They describe the issue and tell you what tests to run to isolate the problem, very handy stuff.

HAHA....I finally figured it out....been a loong day already. So with that information im going to go home this evening and see what results I come up with. Im thinking that my TPS may be going out....gonna test it out and see. Ill report back. Thanks again!

Uhm non of those codes are related to the TPS.

For your orginal problem, yeah your TPS maybe out of spec or the AFM. The backfire may have damaged the O2 sensor.

The second bullet under code 51 in your last post says Throttle Position Sensor.....just leaning that way because of other threads ive read. Ill do some checks and see what turns up.

Whats that you say sonny? No grampas not growing mold! Eh? Oh old, yeah maybe..

Good thing atleast one of us is reading what I type :D sorry.

Ok so i've been gone on military leave and im just now getting back to the yota. So here is what I did last night....I replaced the cracked couplings on my CAI and cleaned the throttle body while I had it all apart. Now after cleaning the TB my idle has gone from 800-1000 to 1500....???

It is still bogging when I hit 2nd gear...its weird because it idles fine...well high now but...it just feels like something is holding it back when I shift into 2nd gear.

Im going to test my TPS tonight and see what I come up with. Ill be throwing on my DT headers next weekend and im going to replace my O2 sensor at that point.

Be careful not to "over-clean" your throttle body. I recommend putting a few drops of oil in the throttle valve and working it back and forth manually(butterfly valve) to make sure it's not sticking. That could cause your idle to jump because it's not closing all the way.

Also make sure the accelarator cable was put back on correctly. If it's too tight, that will also hold the throttle open. You can check this by physically lifting the pedal with your hand when the engine is idling. If it drops, that's your issue. You can also check in the other end where it connects to the TB, there should be a very slight amount of slack so that it's not too tight.