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89 turbo 7mgte supra. Takes about 10 times for it to start, very ruff idle and must feather gas to keep engine from dying. Also no power under load and wants to stall out. Can not get rpm’s up without feathering gas pedal. Will not go past 4K rpm max. Has new fuel pump and filter. Plugs look like running rich. Any ideas? Thanks!
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I'm having a similar issue - rough start, loss of power under load (trying to get over a small bump) and not getting past ~4K rpm.

Have you checked for leaks around intercooler piping? Also vacuum lines?
 

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Hey there, I noticed recently a little while ago I had a drop or two of coolant on the floor and didn’t think much of it. As for the vacuum lines they are almost all brand new. Could it be something that simple as a loose coolant line? That makes no sense but will take your word for it.
 

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Thanks- can I buy a code error check diagnostic sensor? Can’t get car on the road. Has no power under load.
It's not OBD2 so you can't buy something that will give you error codes. You have to jumper diagnostic port in the bay. Then on the dash you'll see the check engine light blink in a sequence - match that sequence up with the corresponding codes.

Engine Codes
 

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A bad AFM, disconnected or leaking intercooler piping, ignition related issues, vacuum leaks, etc... all can cause these issues.
Starting with the error codes would be the way I'd start.

A coolant leak, unless it's into the combustion chamber, will not cause you to have difficulty starting the engine.
 

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Make sure your new fuel pump is installed correctly. I had one installed incorrectly before and my engine was starving for fuel. You can buy a fuel pressure gauge to test it.

Check throughly for boost leaks as well, and happy hunting.
 

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Hey there, I noticed recently a little while ago I had a drop or two of coolant on the floor and didn’t think much of it. As for the vacuum lines they are almost all brand new. Could it be something that simple as a loose coolant line? That makes no sense but will take your word for it.
Since the vacuum lines were replaced recently, I'd double check that they're all secure.

I don't think a coolant leak would cause this - I was referring to the intercooler and air intake pipes. One of my intercooler pipes were cracked and I wasn't getting any power; I fixed that leak and got some improvement. So for sure you could test for a boost leak too.

I agree with MK3Brent - check for codes first. Then move on to checking for leaks.
 

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A coolant leak would DEFINITELY not cause this unless the leak was bad enough to allow you to overheat and fuck off the headgasket/head. If that were the case then you would DEFINITELY have a hard to start car with no power.

This sounds like a leak in the UICP or a sensor that is broken. Even a coolant temp sensor could cause this problem if it thought the car were hot and removed fuel from it constantly. I don't know what direction the coolant sensors fail in on these cars.
 

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Unplug your AFM and try starting the car. If it starts up much more easily and idles OK, but you're limited to 2000rpm, then 90% chance you have a popped off IC pipe somewhere, 10% chance you've got something else going on.

Any recent mechanical work, like a headgasket job, etc? Or was the car running normally before and it suddenly started acting like this?
 

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Unplug your AFM and try starting the car. If it starts up much more easily and idles OK, but you're limited to 2000rpm, then 90% chance you have a popped off IC pipe somewhere, 10% chance you've got something else going on.

Any recent mechanical work, like a headgasket job, etc? Or was the car running normally before and it suddenly started acting like this?
Thank you for your response, no work done on it recently had the engine rebuilt back in 2015. Maybe has 3000 miles since then. This problem occurred pretty quickly and at this point I feel like my starter is going to burn out because it takes so long to start. What is the AFM module you are referring to? I appreciate your help as I have not found the solution to this issue as of yet. No coolant leaks or vacuum line leaks I did replace the throttle position sensor and it only made it worse. Any thoughts? Thanks in advance!
 

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AFM is the air flow meter. It's located directly behind the air filter housing in that metal pipe. Be sure it's plugged in. If you need information on reading or clearing stored error codes refer to the online manual. Click here for the manual You didn't say whether your vehicle was turbo or non-turbo. The Turbo car has a sophisticated acoustic Karman vortex air flow meter. The non-turbo car has a mechanical flap type flow meter. You could check to see if the flap is moving (or stuck open/closed) visually off the car if you have that type.
 
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