85 EFI Toyota Check Engine light

DewYota

Registered User
Location
Lehi, UT
Okay so my check engine light comes on frequently and i sorta feel a loss in power, its not really a lot but i can tell because its hard to get up to speed. is there anyone who could show me how to diagnose this problem in the Provo/Orem area? much help would be appreciated. my truck is falling apart on me and i need help fast!!


:D Anyone who can help ill give you a FREE mountain dew!!:D

Or can anyone attempt to explain with pictures of an 85 4runner EFI Manual Trans
 

wr250

insert lame comment
Location
hurricane
there is a connector you jump (the 2 wire round one)
FuelPump1.jpg


then the CEL will flash codes at you. the number will be blinked at you in .5 sec intervals, then a 4 sec pause , then the next code (if any). when it flashes the last code , it repeats.
the codes:

codes1.jpg


codes2.jpg
 

wr250

insert lame comment
Location
hurricane
Yota4Runner said:
So it was 12 Blinks. the Knock control Sensor Signal. so what does that mean? i have a knock of some kind?

or the knock sensor is not functioning :
wire broken/unhooked
faulty sensor - common

things that can trip the knock sensor:
rod knock
timing chain (guides broken causing chain to slap against timing cover) - common
piston slap (if severe enough)
pre-ignition, detonation (spark knock) -too lean, overadvanced timing notes:
a. timing should be 5 deg BTDC diag connector jumped or 12 deg BTDC unjumped
b. a misadjusted tps will advance the timing and not toss a code
loose motor parts/mounts (usually exhaust parts)
 
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DewYota

Registered User
Location
Lehi, UT
thank you so much man so yeah today i walked into the toyota dealership to see what they had to say they said they could tell me whats wrong for a flat rate of $89.99 to diagnose and find the problem and then they could go from there onto fixing it! i laughed

it could be any of these problems but it does seem to idle rough maybe even misfire or fire out of turn??? engine rocks a little while idleing from not so new engine mounts.(probably85) and the the exahuast pipe is seperated from the front of the cat back and being held together with pressure from exahust hangers and when i got the truck the exahaust manifold was falling off and probably has a blown exhaust gasket. but it has new plugs/wires/oil/air filter/ and engine coolant. does these symptoms lead to anything?
 

wr250

insert lame comment
Location
hurricane
1st thing is to look at the timing chain.

pull the valve cover , look down the timing chain. you should see guides on both sides. you should not see a groove in the aluminum on the drivers side. this groove is a bad thing. repalace chain and guides. possibly the cover too if grooved deeply.this leads to many replacement parts that should be installed whilst the cover is off such as :
front main seal
oil pump
water pump

next is ignition timing. should be ~12 deg btdc unjumpered. anymore advance will cause spark knock on a stock motor.

next is get the exhaust manifold fixed. possible it is rattling, tripping the knock sensor.
 
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