FJ62 Hesitates, no power, rough idles at times

[acoen]

Hi guys been a while since I owned an FJ62....Gotta love'em. Anyway, I purchased this vehicle about a week ago. I purchased it knowing it was not running well. The FJ 62 has 177k miles and is factory stock. Compression about 135+ across the board. I replaced the muffler and tail pipe with factory unit and replaced both converters. The problem I'm having is a horrible hessitation during accelleration and absolutely no power. Idles well sometimes but wants to die (runs rough) after hessitation. I have to blip the throttle a couple of times to get the idle smooth again after hesitation. Just doesn't feel like a fuel problem to me, I would think it would idle poor all of the time if it was the fuel pump....Or wouldn't run at all.

I have read many posts, it acts as if the EGR is stuck open just a hair or is stuck open partially. To add to the puzzle I have a Code 11, which is a ECM or ECU power supply problem. (maybe an old code)

I will reseat the computer harness first thing tomorrow morning...

Where is the main ground? Ground to starter? Are these trucks sensitive to grounding problems.

Any help or tips....Please......! Thanks guys.

 

[grant5127]

I'd check the rubber hoses between the throttle body and air cleaner... they're prone to crack as they age and when the engine flexes the cracks open up allowing the air/fuel ratio get out of whack.....and while your in there examine the throttle body for excessive goop build-up......

 

[euclid]

Search Fuel Pressure Regulator or FPR
Heres the FAQ thread to get you started.

 

[COSkier1]

acoen-
It may be something as simple as the fuel filter. I had some pretty similar symptoms just last week, and that's all it was. It's a cheap fix.
To test your EGR you need a vacuum gauge. With the engine off and the vacuum gauge attached, you should be able to hear it open and close with about 5 lbs of vacuum.
As for code 11, I've found that anytime the battery gets drained down, that code comes up. I wouldn't worry about it. Pull the main relay for the EFI, wait 30 seconds, plug it back in, and the codes should be erased.
Grant's suggestion about checking the hoses is also good. A small leak after the MAF sensor will throw the EFI off. You may have to take off the accordion hose to check it properly.
Good luck.

 

[acoen]

I checked the grounds and connection to the ECM. I unplugged the coolant temp sensor to see if that was failing. I thought I had it but she started hesitating, surging and flat out no or little power at the end of the block. I replaced the fuel filter with my oil service last week. I checked the MAF and it seems to be operating just fine....I don't believe these have the wire resistor, they are door operated correct? The thing will idle fine once it gets settled down, but as soon as you take off she will start to bog, hesitate, and studder all while barely moving down the street. If I punch it during the bog she will down shift raise in RPMs then shutter, pop and buck like she is running out of fuel. I unplugged the FPR which made little or no difference....Seemed to idle poorly with the FPR unplugged.

Is there an easy way to check the fuel pressure? What fuel pressure should I have at idle and WOT?

Now I did contact the PO and he told me he dropped the tank to inspect the fuel pump. He told me the screen was collapsed, he thought it was supposed to be that way and buttoned it back up without changing a thing. Why I don't know. A collapsed fuel sock means that at some point it could have been completely clogged.

Thanks guys keep those suggestions coming....If I could test the fuel pressure I would be just about there.

 

[dwillmo]

Just a suggestion, but are you sure that its got good fuel in it. You say you've had it only a week. Maybe the fuel is just bad and if it was sitting up any length of time it could have a lot of condensation in it. I'd dump some fuel additive in there and try to run all the fuel out of it and then put fresh back in it before I started try to replace everything.

Also, fuel lines break down on the inside and look good on the outside. It will allow air in the lines which causes all kinds of problems. Easy fix too.

 

[COSkier1]

acoen-
do you have an FSM? I went and checked mine, and I'll summarize here.
For "Engine Hesitates/poor acceleration" it lists:
-check for vacuum leaks
-check air filter
-check diagnostic system (which you did)
-check ignition spark
-check timing
-check fuel pressure
-check injectors
-check spark plugs
-check EFI circuit (fusible links, fuses, main relay, air flow meter, water temp sensor, air temp sensor, throttle position sensor, injector signal circuit.
I can look up something else if you need it.

 

[acoen]

Thanks guys, I'm on it. Any way to check Fuel pressure on one of these things? What pressure am I looking for?

Thanks again,

Aaron

 

[COSkier1]

Well, as far as I can tell, you need a pressure gauge, and it gets installed at the cold start injector. Never done it myself. But you're looking for a minimum pressure of 37psi with ignition on but not running, 37psi at idle with FPR disconnected, and 33 psi with FPR connected.

 

[acoen]

Thanks guys, I've been reading up a little. I'm going to bypass my EGR to see if it is the culpret. The method to doing this is very easy, could bet that the modulator is bad or clogged. Second I'm going to test Fuel pressure using the adviced 37 PSI for the base. Gut feeling at this point is that the EGR system is not operating properly....Especially since the damn thing can idle so well.....

For the past 5 or 6 years I have gotten away from Land Cruisers and other Toyota 4x4s....to follow my love for the Buick Grand National (I have owned several including my 1986 factory stock GN with 63k miles...looks more like 20k (pictured). I never forgot about the Toyotas, purchased a 2004 Sequoia then this 1990 FJ62. I am definitely a Toyota fan first although Buick out did themselves with the turbo charged intercooled 3.8 liter V-6.

Anyone play with installing a Turbo Charged V-6 in a Land Cruiser? That would be fun!!!!!

Thanks again

 

[smtyblt]

Cam here with Iron Pig

First take the Idle Speed Control (ISC) off the throttle body and clean it. Be carefull with this peice it is over 400$ to replace new

Second if that is not it give her a tune-up, ie wires, cap, rotor, plugs. It is at the age the wires are shot if they are original.

Third Clean and adjust Throttle Position Switch ( TPS ) and the flap inside the throttle body( do not remove, just clean )

 

[acoen]

Cam here with Iron Pig

First take the Idle Speed Control (ISC) off the throttle body and clean it. Be carefull with this peice it is over 400$ to replace new

Second if that is not it give her a tune-up, ie wires, cap, rotor, plugs. It is at the age the wires are shot if they are original.

Third Clean and adjust Throttle Position Switch ( TPS ) and the flap inside the throttle body( do not remove, just clean )

Cam and guys

Thanks, I cleaned the ISC, the pintle was carboned up pretty bad. Now I will need to clean and adjust the TPS. What voltage am I looking for on the TPS adjustment? What is a good idle speed. How do I go about resetting the ISC after installing it back (she is idling to slow now barley running. On GM products you use a jumper at the ALDL connection and extend the pintle to its extent and adjust idle speed. Once you have idle speed you check voltage at your TPS with ignitions switch on.....I'm not sure on the proceedure for the Toyota.

When dead cold she runs ok for about a block or two or three minutes if that, then it starts running like crap....Hesitation, bog, bucking etc. I isolated the EGR by plugging the EGR, EGR control diaphram, and plugging some lines as specified on this site, no change.....But if my EGR is stuck open a little.... it wouldn't make a difference....Would it?

Throttle body is clean, the accordian hose was loose at the throttle body, I almost jumped for joy, but tightening it made no difference.....Damn!

Pulling out my hair a little....Man.....HMMMMm anyone willing to give me a call on this one to discuss? (559)271-9622....Located in Central Ca....If I could check fuel pressure I would be almost there. I'm almost at the point of splicing a hose at the fuel filter and placing a gauge there.....I just don't want to do that......

 

[ozwick]

Has anyone suggested trying another coil?

Might be a cheap fix if this is it?

ozwick

 

[acoen]

Has anyone suggested trying another coil?

Might be a cheap fix if this is it?

ozwick

Good point, I will check that tomorrow, I checked the price for a new coil and it was under 30 bucks...

 

[smtyblt]

Cam and guys

Thanks, I cleaned the ISC, the pintle was carboned up pretty bad. Now I will need to clean and adjust the TPS. What voltage am I looking for on the TPS adjustment? What is a good idle speed. How do I go about resetting the ISC after installing it back (she is idling to slow now barley running. On GM products you use a jumper at the ALDL connection and extend the pintle to its extent and adjust idle speed. Once you have idle speed you check voltage at your TPS with ignitions switch on.....I'm not sure on the proceedure for the Toyota.

When dead cold she runs ok for about a block or two or three minutes if that, then it starts running like crap....Hesitation, bog, bucking etc. I isolated the EGR by plugging the EGR, EGR control diaphram, and plugging some lines as specified on this site, no change.....But if my EGR is stuck open a little.... it wouldn't make a difference....Would it?

Throttle body is clean, the accordian hose was loose at the throttle body, I almost jumped for joy, but tightening it made no difference.....Damn!

Pulling out my hair a little....Man.....HMMMMm anyone willing to give me a call on this one to discuss? (559)271-9622....Located in Central Ca....If I could check fuel pressure I would be almost there. I'm almost at the point of splicing a hose at the fuel filter and placing a gauge there.....I just don't want to do that......

the TPS is set to a range checked at closed throttle, partial throttle, and wide open. It is check with an ohm reading if it is bad, at full throttle no resistance. that part from Toyota is about 100 bucks but that fixed my persanal truck.

there is no adjusting that ISC it is preset. (it is possible but if that fixes it, it is just a patch, there is something else wrong.

Coil, fuel pump or TPS are good guesses

The coil not so much those coils generally just go bad.

Fuel pump maybe but normally the same they just go bad.

TPS's can be adjusted but also normally just go bad.

One check that is good. start the truck and gently raise the RPM's slowly and see if you can find a spot that the engine speed changes up and down with out your foot moving. If you find a spot like that, The TPS is bad

Run a couple of checks and them call me at the shop tomorrow or thursday

Cam

General Manager

Iron Pig Offroad
540*361-7400

 

[acoen]

the TPS is set to a range checked at closed throttle, partial throttle, and wide open. It is check with an ohm reading if it is bad, at full throttle no resistance. that part from Toyota is about 100 bucks but that fixed my persanal truck.

there is no adjusting that ISC it is preset. (it is possible but if that fixes it, it is just a patch, there is something else wrong.

Coil, fuel pump or TPS are good guesses

The coil not so much those coils generally just go bad.

Fuel pump maybe but normally the same they just go bad.

TPS's can be adjusted but also normally just go bad.

One check that is good. start the truck and gently raise the RPM's slowly and see if you can find a spot that the engine speed changes up and down with out your foot moving. If you find a spot like that, The TPS is bad

Run a couple of checks and them call me at the shop tomorrow or thursday

Cam

General Manager

Iron Pig Offroad
540*361-7400

Thanks my friend, I truely appreciate the help. I will give you a call tomorrow....

Aaron

 

[dwillmo]

I had a Toyota pickup once, it would run fine for about 15 minutes. Then it would start bucking and missing and eventually would die. After it cooled a while, it would start and run fine for a few minutes before it would do the same thing all over again. Eventually I could make it back home. I replaced the coil first. Then fuel filter and then plugs/wires. Nothing helped until somebody suggested that it sounded like it was vapor-locking. Had water in the fuel. Added some STP and the problem went away.

 

[acoen]

the TPS is set to a range checked at closed throttle, partial throttle, and wide open. It is check with an ohm reading if it is bad, at full throttle no resistance. that part from Toyota is about 100 bucks but that fixed my persanal truck.

there is no adjusting that ISC it is preset. (it is possible but if that fixes it, it is just a patch, there is something else wrong.

Coil, fuel pump or TPS are good guesses

The coil not so much those coils generally just go bad.

Fuel pump maybe but normally the same they just go bad.

TPS's can be adjusted but also normally just go bad.

One check that is good. start the truck and gently raise the RPM's slowly and see if you can find a spot that the engine speed changes up and down with out your foot moving. If you find a spot like that, The TPS is bad

Run a couple of checks and them call me at the shop tomorrow or thursday

Cam

General Manager

Iron Pig Offroad
540*361-7400

I changed the FPR today, really thought I had it, she fired right up and idled, but if you drive it and give it any fuel she is just flat, no power. Runs pretty good when you first start it and go down the road a block or two, then it starts breaking up as it warms slightly and worse the warmer it gets. I can come to a stop, blip the throttle a couple times and she will idle pretty good. Took your advice, off throttle runs ok, slight tip in she will start to pick up speed then once I give it just a little more throttle she flattens out with no power. If I increase throttle during the hesitation, I get some popping out of the intake and sometimes exhaust. Almost like a lean condition. The exhaust smells lean to me, not like coolant or oil just lean. I'm not throwing codes, check engine is not on.

I've seen coils do this, EGRs do this, clogged filters do this....The EGR modulator is vibrating (almost buzzing) while running...I'm really getting tired of this. Tomorrow I will run a vacuum test.

In all actuality the thing runs a little better with the new FPR, but not much.

I will give you a call tomorrow....Don't have much time after work to play with it, but I will have a little time this weekend.

 

[ozwick]

Just another thought, Have you checked or adjusted the valves?

 

[smtyblt]

It is starting to sound like you have a blocked cat or both.

They will breath untill they get hot and then the truck wont run right.