Toyota Question

[BDBWTE]

Okay I have a 87 Toyota pickup 4x4 5spd that I wheel in... and just recently it's developed a studder when ever you get into the throttle decent.  I've had the motor put in time and I'm going to put a new fuel filter and plugs on it tomorrow.  It was 105,000 miles which is nothing and it's a Turbo 22R (2.4L)

 

I was thinking studder because lack of fuel thus I checked the pump...good and I'm going to replace the filter tomorrow and through in plugs for good measure.  The motor does it when it's cool as well as hot and I run premium with stock 5-7psi boost so I doubt it's detonation.  

 

CMNT I know this isn't your forte (sp?) but I need a hand here... When the truck studders if you let off the gas then ease back into it it will stop but if you keep on it a SES light comes on and the truck usually back fires...

 

I know very little about 22RE's much less a turbo.  Thanks for the comments in advance..

[Black02Silverado]

I'm not a Toyota person but can throw out some ideas maybe. Is it fuel injected or carb?  If carb maybe needs adjusted?

 

Does it have a timing chain, possible wear even though it is in time that initial slack could make it studder, just a thought. I know that many miles is nothing. I had a friend with 350k on his 88 SR5 4x4.

 

Maybe take it to Auto Zone and have them check for codes since the SES light was on.

 

Have you been sitting in the seat the right position? Some times if you lean to the left more than normal it can cause a studder.

 

Like I said I'm not much of a Toyota person but that is what I can think of to look for, oh except for the sitting position of course.

 

[CMNTMXR81]

Have you been sitting in the seat the right position? Some times if you lean to the left more than normal it can cause a studder

 

Seriously though;

 

When the truck studders if you let off the gas then ease back into it it will stop but if you keep on it a SES light comes on and the truck usually back fires...

 

Sounds to me like 1 of 2 things and they may be even intertwined.

 

1) Timing does not retard

and/or

2) It's still dumping fuel in causing the back fire

 

With it being turbo, this is not something I am readily qualified to diagnose, but have you looked at the blowoff/pressure relief valve on the turbo?  Either it's blowing open with minimal pressure while the ECM is still delivering advanced amounts of timing and fuel OR the blow off isn't opening fast enough to relieve pressure while the ECM is still delivering advanced timing and fuel.

 

I'm just taking a wild stab in the dark.  

[Wingnut]

Does it have a knock sensor?

 

I had an 82 with the 22r in it, and as I recall, it was either that or an O2 sensor that went bad, and caused it to detonate......Been a long time since I had that truck...Wish I had it back.

 

Just my .02, but it aint worth that much.

[CMNTMXR81]

That could very well be.  That knock could still come from advanced timing and extra fuel still being dumped in causing pre-ignition, causing backfiring.  A faulty knock sensor would not pick this up and not retard timing and fuel quick enough.

 

An O2 sensor would cause either constant richness or constant leaness once the ECM went into closed loop.  If there is a way to measure the O2's mV output, .485mV is stoich 14.7:1.  More than .485 is going rich, less than .485 is going lean.

[BDBWTE]

Thanks for your guy's time.  I found out yesterday that Toyota didn't release the codes for the 87 Toyota pickups..thus I cannot get the free diagnostics (sp?) I would have to go to a dealer and spend lots of $$$$$.