Engine Two problems fox dies when wot and...

[Glue1]

Hi Hope I can get some help here I have a 87 foxbody the first problem that I have with my mustang it’s that I drive it and when it hit open throttle it starts to die but when I let go the throttle The engine stays on like normal And the second problems it’s that I hooke the air filter on and the engine stars running bad and wants to die but I take the filter of and runs fine i changed maf sensor and does the same thing

Thanx

 

[General karthief]

Thanks for including a picture, the air filter on the end of the maf will not work, as you have found, it needs space between each other, I would put a stock air box back in or get a cai that puts the filter inside the fender. This may solve both your issues.
I would also go here:

Help me create the "Surging Idle Checklist"

Updated 26-Oct-2019 to clarify creeping idle RPM increase as the car is being driven. Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank Checklist. They are very effective in finding and eliminating the problems by use of...

forums.stangnet.com

This won't help you with your lack of punctuation but it will show you how to check for codes and test and correct many idle/stall issues common with these cars.
Thanks to jrichker and others for contributing to the tech/how to threads.

 

[General karthief]

Optical illusion

 

[Glue1]

I tried with this pipe to give more space between sensor and throttle but still does the same

 

[Glue1]

I

Thanks for including a picture, the air filter on the end of the maf will not work, as you have found, it needs space between each other, I would put a stock air box back in or get a cai that puts the filter inside the fender. This may solve both your issues.
I would also go here:

Help me create the "Surging Idle Checklist"

Updated 26-Oct-2019 to clarify creeping idle RPM increase as the car is being driven. Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank Checklist. They are very effective in finding and eliminating the problems by use of...

forums.stangnet.com

This won't help you with your lack of punctuation but it will show you how to check for codes and test and correct many idle/stall issues common with these cars.
Thanks to jrichker and others for contributing to the tech/how to threads.

will check this list thanx

 

[Blown88GT]

Problem 1.
Probably the fuel pump. You need a pressure gauge to see what it does when you "hit the throttle".

Problem 2.
The filter on the MAF will work if the MAF housing is a C&L with the proper calibration tube for that configuration.

 

[Wayne Waldrep]

This won't help you with your lack of punctuation

I just don't get why so many first time posters run 500 words together and we have to figure out where each sentence stops. Seems to happen weekly now. I hate it!

Now the car. There also needs to be space between the MAF and filter. My last dyno session required the addition of a 4" tube between the MAF and the filter. This was the only way to get the correct reading.

 

[a91what]

Oh the turbulence!!!

seriously though


these guys are correct, the MAF is susceptible to issues when the air flow is not laminar [read smooth] There is/are two designs for a MAF, the first [stock style foxbody and most replacements] are designed to be placed in a run of tubing with at least 10x the diameter of the MAF of straight pipe before and after the sensor to achieve laminar flow.... for the vast majority of us this is nigh impossible!! thats ok they work fine if you give them 4x the diameter of straight pipe.. if there is not enough space to allow for that a minimum of 2x and a screen will smooth the air just fine..

the second type is designed for the filter to be placed right on the end of it, like you have done....

you have a maf designed to be in a piece of pipe.. place a 3-6" piece of pipe between the filter and the tube to fix the issue

 

[Glue1]

I just don't get why so many first time posters run 500 words together and we have to figure out where each sentence stops. Seems to happen weekly now. I hate it!

Now the car. There also needs to be space between the MAF and filter. My last dyno session required the addition of a 4" tube between the MAF and the filter. This was the only way to get the correct reading.

Sorry about how I type but I have a hard time speaking or typing in English but I’m trying my best if there’s something wrong with that i can just delete the post

 

[General karthief]

Sorry about how I type but I have a hard time speaking or typing in English but I’m trying my best if there’s something wrong with that i can just delete the post

we will deal with it

 

[a91what]

ha most of us can barely speak and type in english and its our primary language.. so no worries

 

[Decipha]

have you verified your air filter isn't clogged?

 

[jrichker]

Hi Hope I can get some help here I have a 87 foxbody the first problem that I have with my mustang it’s that I drive it and when it hit open throttle it starts to die but when I let go the throttle The engine stays on like normal And the second problems it’s that I hooke the air filter on and the engine stars running bad and wants to die but I take the filter of and runs fine i changed maf sensor and does the same thing

Thanx

Does the problem only occur when the engine is warm?

 

[Glue1]

have you verified your air filter isn't clogged?

Brand new k&n

 

[Glue1]

Does the problem only occur when the engine is warm?

The open throttle problem yes And the maf problem all the time

 

[jrichker]

The open throttle problem yes And the maf problem all the time

High speed miss on a warm engine
Revised 24 June 2019 to add new source & part number for TFI removal tool .

The TFI module mounted on the distributor is one of the culprits for a high speed miss on a warm engine. The other suspect is the PIP sensor inside the distributor. If the problem does not occur when the engine is cold, the TFI module or PIP is definitely suspect. Dumping the codes may help determine which one it is. You may need a special socket to remove the TFI module, but most auto parts stores will have one for $5-$7.

It is not uncommon that the replacement parts may be defective; TFI modules made by non Ford manufactures seem to have a high failure rate.

Be sure to use plenty of the heat sink grease on the new TFI and clean the old grease off the distributor.

Lisle P/N 64650
See https://shop.advanceautoparts.com/p...0kH8DTh2LmTcgnmc_E4aAuCIEALw_wcB&gclsrc=aw.ds

diagram courtesy of Tmoss & Stang&2Birds