Question about Cars & Trucks

2 Answers

Engine light comes on when engine is hot. Power is the greatly reduced. When engine is cold it drives perfectly. Toyota 7afe 1.8 litre fuel injection, modded aspirated. I've rebuild the motor due to a big end bearing knock which was caused by a faulty/ pirate oil pump. Engine starts, idles, revs up all the way to 7200rpm, doesn't smoke and has no abnormal noises. Its perfect. No loose plugs no leaks. Sufficient oil pressure. But when driven and the engine is hot (driven hard or soft or normal) the engine light then comes on and power is reduced tremendously. This also started occurring a week before I rebuild the engine. I initially thought it was the bearing knocking noise interference with the knock sensor. Under light acceleration its fine, under medium to heavy acceleration the car slightly nose dives. Believe me, mechanical function and timing of the engine is perfect. essembly wise. What is the problem?

Posted by on

2 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 2 Answers

You need to overhaul your fuel injection and if does not work you have loose compression on your piston ring . engine top overhaul can help you

Posted on Mar 28, 2015

  • Level 1:

    An expert who has achieved level 1.

    Corporal:

    An expert that hasĀ over 10 points.

    Mayor:

    An expert whose answer gotĀ voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 16 Answers

Hello,
There is a possibility that the old motor was not burning properly and you have carbon build up on the O2 sensers. A poorly functioning O2 senser will not allow the Fuel/Air mixture to work as you give it gas under load. You could have multiple O2 sensers too.

Posted on Dec 08, 2014

6 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

co7196
  • 3433 Answers

SOURCE: 2004 Nissan Quest - Engine chatter/knocking

Ther e is a chance your injectors are leakin g down and there is excess fuel in the cylinders. Not a good thing. So, you fuel pressure and injectors need chkg. good luck

Posted on Jun 09, 2009

  • 6 Answers

SOURCE: loud knocking or tapping sound when engine is cold

Take our oil pan off from under your car and there should be 4 to 5 covers over a rod bearing. wiggle each one of them and find out which one is loose. take that cover off of the one that is wiggling and get the rod bearing out. order a new one from auto zone and replace it. The knocking in your motor can end up where you will need a whole new motor. so get it done before its to late.

Posted on Jul 22, 2009

  • 1 Answer

SOURCE: loud diesel knock nissan terrano II head just replaced.

some black smoke comes out when i put foot down and loses power when goiong uphill i have a nissan mistral/terrano 2.7td

Posted on Aug 20, 2009

  • 1 Answer

SOURCE: engine or transmission knock / rattle upon

I had the same problem on my 2006 Lucerne and it was the engine mount located on the front of the vehicle behind the radiator.

Posted on Aug 24, 2009

duane_wong
  • 6826 Answers

SOURCE: My Toyota Vitz has a

Knocking can be caused by a bad bearing somewhere in the engine. When the engine is accelerated it might go away due to higher oil pressure.

When did you have the oil changed and how many miles does it have?

Is the knocking rapid (5 or 6 times a second) or periodic (1 or 2 times a second)?

Some knocking is due to low octane gasoline if you experience it at highway speed.

Good luck on solving this knocking problem.

Posted on Oct 07, 2010

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

7AFE corolla acceleration problem. Hi I am a diesel mechanic with lots of experience. EXPLANATION. I had my cars engine done up by a 'famous' toyota specialist. He said he would use genuine parts. He...


SOUNDS LIKE YOU HAVE BEEN VERY BUSY,THE ONLY THING I CAN THINK OF TO CHECK WOULD BE THE EXHAUST FOR RESTRICTION (COLLASPED PIPE,MUFFLER ,CAT CONVERTER) HOPE THIS HELPS .LET ME KNOW.

Dec 19, 2014 | Cars & Trucks

1 Answer

What should the compression be at on a 1997 geo prizm.


which engine. the 1.6 or 1.8 toyota engine (its a corolla in snake skins) 4afe or 7afe ,
cold or hot?
warm / hot , is specified in the Factory service manual.
most cars get at least 150PSI (wide open throttle) hot (warm) , sparks out.
the compression ratio is the key factor for compression.
The 7A has 9.5 CR, way more than the 4A.
if way low on all cylinders the cam belt slipped, ever do a belt job at 60k?

here is an actual test off a good, 7afe
Compression test dry: CYL 1=210/CYL 2=200 CYL 3=205 CYL 4=205

when the belt slips the PSI can drop to 90 easy
and fail.
rules:
battery charged
spark plugs removed
block open throttle (and if smart pull fuel pump fuse)
crank until the needle goes steady. using remote start cable at starter lug, works best (safety , 3 ways)
bingo
repeat

Nov 20, 2014 | 1997 Geo Prizm

1 Answer

Prizm troubleshooting


which engine the 4AFE or 7AFE toy engine.
?????????????????????????????????
but runs with the fast right foot , trick , right?
and runs perfectly if you keep the right foot happy, right?
all key factors in any engine diagnosis, but im not driving it so.....??

the cars EFI uses a device called and ISC,
this is idle speed controller.
if it sticks closed, it makes starting hard, and hot starts insane hard.
if it sticks open , hard starts, and when does screams.
some time the iSC is ok, but the engine runs so bad, it can't do its job.

clean the iSC. then test it. make sure it works. perfectly.
the FSM book covers this.
in fact that toyota engine, Toyota has huge documents on line
better that any car made !!! on how all this works....
Toy rules this roost.

hint on your car, lie (fib) and google search 4AFE (if it is)
Search "Toyota 4AFE iAC or ISC)
and find vast information on IAC and ISC>
some cars have 2 valves , one thermal one electric.
the thermal iAC is only working below 150F.
toy name Aux air? your car has both. 4A

the iSC is electric idle controls. (ECU runs it)
ECU controls it at all times, ECU keep idle correct at all times.
in many cases IAC means ISC,

Jun 06, 2014 | 1990 Geo Prizm

1 Answer

Fuel injector diagram


old post
no engine stated, ?? which one? 4AFE or 7Afe (TOY ENGINE)
the harness will not allow cross wiring injectors
how did you do that?
the #1 injector is on #1 cylinder
and on #1 fuel rail port.
the #1 cylinder on inline engines, the crank pulley end.
if you need wire colors, we can do that too.
or log in to mitchells DIY and read. that.
here is the 7aFE wires
B-O is 12vdc power key on, the ECU fires the 4 on right.

23865545-flsdwf0rx41rbdaez4cmhnol-2-0.jpg end old post day.

Mar 19, 2014 | 1993 Geo Prizm

1 Answer

They replaced my car with new battery but still stalling - no power at all. What do you think is the problem?


power?

electrical power, as in dim lights
or engine power, like you can go up a hill fast wide open throttle
is it just quick loss of engine power or constant.
hot engine cold engine or both.?

stalls come on may ways.
1: lost DC electrical power lost to EFI system.
2: lost compresson, fails hot?
3: lost spark , try a 60k mile tuneup now, if skippped, they are critical.
4: bad fueling

there are simple tests for each failure path./
do you want to, do you have tools, ???? or just want guessing../?????

ok , i will guess, warning all of mine are wrong.
1: the Fuel pump regulator is bad stuck wide open and fuel pressures
is 1/2 spec at 15psi, car is gutless all the time.
one down 49 to go..

Feb 02, 2014 | 1997 Toyota RAV4

1 Answer

Engine light comes on heat blowed cold air and car runs hot and wont crank now


Number 1: get the code; even if they light turns off an on, the code will be stored in the computer.

It sounds like you could have a variety of issues and more information needs to be given. How is the car running? Does it run & idle perfectly or does it stumble?

Dec 10, 2013 | 2000 Toyota Camry Solara

1 Answer

7AFE ENGINE FAILING TO START NO POWER ONFUEL PUMP AND WINDOWSI HAVE A TOYOTA PREMIO WITH 7AFE ENGINE IT HAD WIRING PROBLEMS BUT IT WAS ABLE TO RUN THOUGH CHARGING SYSTEM WAS NOT THERE AND WINDOWS WERE


No you have got your wires crossed on this one ,boy what a pun ? Anyway i cannot help with a good look to see what you have done wrong so i would suggest that you ask a local mechanic to have a look for you

Dec 06, 2012 | Cars & Trucks

1 Answer

My truck is in reduce engine power mode and i need to get it off to drive it to a shop it runs great untill the temp reaches a 100 degress. oh and its a 2003 chevrolet silverado 4.8 litre


Sounds like a problem with the cooling system - when it has enough coolant it won't run too hot so won't trip ''reduced power mode". If coolant is at max already it's either the water pump or the thermostat having a problem.

Jun 29, 2011 | Chevrolet Silverado 1500 Cars & Trucks

1 Answer

Hello all. i have a toyota carina ti 1.5L, 96 model. 5AFE engine with AT. from last 10 days, suddenly my gear is giving problem. i am shifting gear from parking to drive, it is taking like 2 seconds to...


No you are looking for expensive solutions which it may not need ---start engine and make sure handbrake is on hard then select reverse and check the fluid level with the engine running ,i think you will find its about just under a litre short of transmission fluid but you cannot check it properly unless its in reverse with engine running ,and for good measure put a brick behind the drive wheels .

Feb 03, 2011 | 1995 Toyota Corolla

1 Answer

My Toyota Camry 1996 2200 Engine is guzzling fuel


all the sensors.the cold in your engine/vehicle are important none of them to be disconect even temporaily the cold hot sensor sending unit read the temperature of the engine and send the information to the computer ....engine cold ...moore fuel, engine hot less fuel please plug in all the plugs and you wiil see best results

Dec 15, 2008 | 1994 Toyota Camry

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

135 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cars & Trucks Experts

yadayada
yadayada

Level 3 Expert

75822 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Randy Ohler

Level 3 Expert

14585 Answers

Are you a Car and Truck Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...