80 series bad idle, sluggish acceleration when cold (1 Viewer)

[sp4]

I bought my 1994 1fz-fe 80 series a month ago, being to hasty to service it I pulled off the intake boot, changing the airfilter and then cracked it! Then not realising I had cracked it, I drove and it started to die on me, so badly I was towed.
I then found the issue and replaced the boot, in doing so I again was not careful and then pulled off the hose going from the airfilter to the vacuum boost lines, I drove like this for 1 hour and then fixed this issue.
The car is in Cali and was not smogged, it was thowing a CEL for bad O2 sensors, which I replaced with the denso ones https://www.amazon.com/dp/B07WSG3R23?ref_=pe_123509780_1038749300_fed_asin_title, they came with a slighty different wiring harness, so I chopped them to make them fit the original wiring fittings.
It then passed Smog!!
Since then I have had a bad idle and when I accelerate when cold it can be awfuly slugish and feel delayed.When starting the car the idle shoots up to 2000 and then slowly comes down to about 600 where the engine starts to shudder ever so slightly, when put in drive or reverse the rmp then drops to 500 and shudders alot more, however it never stalls.
I have tried to combat this by:

• Cleaning the MAF
• Cleaning the EGR (it leaks ever so slightly, like 1 drop every 30seconds but the diaphragm seems to work allowing the piston to be pushed in and out)
• Checked and Set the TPS according to the FSM
• Cleaned and Checked the IAC as per FSM
• Changed the distributor cap
• Changed the spark plugs
• Changed the spark cables
• Changed the distributor rotor
• Changed the air filter
• Changed the oil filter
• Changed the oil
• Changed the fuel filter
• Put some injector cleaner in with the Gas
• Visual inspection of the wiring harness next to the egr (looks fine no signs of melting)
• Smoke test (all vacuum lines seem good)

Things I am yet to try:

• Test the ECT
• Test the fuel injectors
• Cut open wiring harness next to the egr for a deeper inspection
• Change the fuel pump
• Change the fuel sock
• Change the charcoal filter

Is there anything I am missing that is obvious I should check?
Really appreciate how much of an amazing resource ih8mud has been thank you all in advance for any useful insights.

 

[Old Nick]

I bought my 1994 1fz-fe 80 series a month ago, being to hasty to service it I pulled off the intake boot, changing the airfilter and then cracked it! Then not realising I had cracked it, I drove and it started to die on me, so badly I was towed.
I then found the issue and replaced the boot, in doing so I again was not careful and then pulled off the hose going from the airfilter to the vacuum boost lines, I drove like this for 1 hour and then fixed this issue.
The car is in Cali and was not smogged, it was thowing a CEL for bad O2 sensors, which I replaced with the denso ones https://www.amazon.com/dp/B07WSG3R23?ref_=pe_123509780_1038749300_fed_asin_title, they came with a slighty different wiring harness, so I chopped them to make them fit the original wiring fittings.
It then passed Smog!!
Since then I have had a bad idle and when I accelerate when cold it can be awfuly slugish and feel delayed.When starting the car the idle shoots up to 2000 and then slowly comes down to about 600 where the engine starts to shudder ever so slightly, when put in drive or reverse the rmp then drops to 500 and shudders alot more, however it never stalls.
I have tried to combat this by:

• Cleaning the MAF
• Cleaning the EGR (it leaks ever so slightly, like 1 drop every 30seconds but the diaphragm seems to work allowing the piston to be pushed in and out)
• Checked and Set the TPS according to the FSM
• Cleaned and Checked the IAC as per FSM
• Changed the distributor cap
• Changed the spark plugs
• Changed the spark cables
• Changed the distributor rotor
• Changed the air filter
• Changed the oil filter
• Changed the oil
• Changed the fuel filter
• Put some injector cleaner in with the Gas
• Visual inspection of the wiring harness next to the egr (looks fine no signs of melting)
• Smoke test (all vacuum lines seem good)

Things I am yet to try:

• Test the ECT
• Test the fuel injectors
• Cut open wiring harness next to the egr for a deeper inspection
• Change the fuel pump
• Change the fuel sock
• Change the charcoal filter

Is there anything I am missing that is obvious I should check?
Really appreciate how much of an amazing resource ih8mud has been thank you all in advance for any useful insights.

Was your rig running well before the in-take incident?

 

[sp4]

Was your rig running well before the in-take incident?

Yes running perfectly!

 

[Old Nick]

Yes running perfectly!

You've had the battery disconnected a number of times, I'm guessing. Have you been able to drive it sufficiently for the ecu to re-set? My 62 and my wife's 80 both do a little "searching" for correct RPMs after the battery has been disconnected. But, after a drive, the ecu sorts itself out and RPMs return to factory spec.

Beyond that (and I know that you've done a smoke test for exhaust leaks), since the problems started after the crack in the in-take hose and the disconnected hose, I would go back over the simple things first.

Sorry that I can't be much more help than that. I'm sure that you'll get some input from others soon.

 

[Old Nick]

Do you have the Factory Service Manual? If not, download that thing and go through the procedures there.

A Mud member produced a fantastic, bookmarked PDF of the 80 series FSM. That wonderful thing will help... a lot.

My wife has a 1994 FZJ80 as well. It was a basket case when we bought it. Rusted out, neglected and a mess... but triple locked. Got it for cheap. The FSM helped me to get it running again.

Edit: the FSM is in the resources section here.

 

[effjay80]

Did you mess with the VAF when you cleaned it, especially the screws on it?

 

[Old Nick]

BTW... you need one of these... ... trust me... they help... lol.

 

[sp4]

You've had the battery disconnected a number of times, I'm guessing. Have you been able to drive it sufficiently for the ecu to re-set? My 62 and my wife's 80 both do a little "searching" for correct RPMs after the battery has been disconnected. But, after a drive, the ecu sorts itself out and RPMs return to factory spec.

Beyond that (and I know that you've done a smoke test for exhaust leaks), since the problems started after the crack in the in-take hose and the disconnected hose, I would go back over the simple things first.

Sorry that I can't be much more help than that. I'm sure that you'll get some input from others soon.

I’ve probably done 500miles since the last reset

 

[sp4]

Did you mess with the VAF when you cleaned it, especially the screws on it?

I didn’t touch the screws

 

[sp4]

You've had the battery disconnected a number of times, I'm guessing. Have you been able to drive it sufficiently for the ecu to re-set? My 62 and my wife's 80 both do a little "searching" for correct RPMs after the battery has been disconnected. But, after a drive, the ecu sorts itself out and RPMs return to factory spec.

Beyond that (and I know that you've done a smoke test for exhaust leaks), since the problems started after the crack in the in-take hose and the disconnected hose, I would go back over the simple things first.

Sorry that I can't be much more help than that. I'm sure that you'll get some input from others soon.

Will try one more smoke test tomorrow

 

[sp4]

Do you have the Factory Service Manual? If not, download that thing and go through the procedures there.

A Mud member produced a fantastic, bookmarked PDF of the 80 series FSM. That wonderful thing will help... a lot.

My wife has a 1994 FZJ80 as well. It was a basket case when we bought it. Rusted out, neglected and a mess... but triple locked. Got it for cheap. The FSM helped me to get it running again.

Edit: the FSM is in the resources section here.

Yes the dam has bee. A life saver!!

 

[cruiserdan]

Yes running perfectly!

If it wasn't broken before you started fixing it, something you did most likely caused it and has not been successfully reversed. You probably still have an un-metered air leak on the intake side.

 

[Kernal]

How did you clean the MAF and IAC?

Did you replace (or forget) the gasket for the EGR valve (and Throttle Body if that was removed), new O-ring for the IAC valve? Any of those
could cause an air leak.

If you have or can buy a scan tool, even a cheapo, you can look at a few parameters including the ECT sensor temp readout.
Edit: the OP's 80 is a 94 model (OBD 1, missed that) so you can use a scan tool that is designed to work on Toyota OBD 1 vehicles.
Search you tube or Amazon for OBD 1 scan/scanner/diagnostic tool

 

[sp4]

Cleaned the mag with MAF cleaner, cleaned the iac, with carb cleaner, tested it on the battery per FSM, after cleaning worked well. New egr gasket, new iac o ring, new throttle body gasket. It’s a 1993 so still one 1.

 

[cruiserdan]

If you have or can buy a scan tool, even a cheapo, you can look at a few parameters including the ECT sensor temp readout.

This is not an OBDII truck. He would need a factory break-out box, if he could find one.

 

[sp4]

How did you clean the MAF and IAC?

Did you replace (or forget) the gasket for the EGR valve (and Throttle Body if that was removed), new O-ring for the IAC valve? Any of those
could cause an air leak.

If you have or can buy a scan tool, even a cheapo, you can look at a few parameters including the ECT sensor temp readout.

This is not an OBDII truck. He would need a factory break-out box, if he could find one.

What is a factory break out box?

 

[cruiserdan]

What is a factory break out box?

The precursor of an OBDII reader. Very elaborate and brutally expensive.

 

[petegangies]

Please do a thorough visual inspection of all vacuum lines. The smoke tester didn't pick up 2 vac leaks on mine and I performed it twice.

 

[sp4]

Ok so did a smoke test today and can confirm no leaks as well as tested the ECT and with in spec as per FSM

 

[petegangies]

Ok so did a smoke test today and can confirm no leaks as well as tested the ECT and with in spec as per FSM

did much coolant drain out when removing the ECT sensor?