Car only starts when you put gas pedal to floor

[f8tlfiveo]

i have an 88 lx 5.0, just recently i replaced the TFI module to fix a similar problem and now if i let the car sit for a while and start it. it struggles to start the first time without pressing on the pedal at all. shut the car off in 10 seconds and you have to press the pedal to the floor for the car to start. i swapped another coil and tfi module from my brothers 93 gt . neither one made a difference. i looked over the checklist but didnt see anything that looked like it would help. any help will be appreciated, i want to go to the track next weekend.

 

[BYRDPE]

try swapping the entire dizzy.

 

[bubba-dough]

Have you tried pulling the codes? It could be a number of things from act sensor to tps to ect to the dizzy....I would check for codes first

 

[HISSIN50]

Any codes?

Flooring the gas shuts off the injectors. Are you flooding the engine?

Otherwise, if you think it's more of an issue of air bypassing the throttle plate (a bad or dirty IAC), which you circumvent with the opening of the throttle, check the IAC function and cleanliness.

 

[jrichker]

Dump the codes and look for code 21, 51 or 61: they are all ECT codes. One of the symptoms of ECT problems is hard starting on a warm engine and having to press the throttle to the floor to get the engine to start.

Also look for code 14 - PIP sensor - they will also cause warm starting problems.

Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

See Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical

If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see EQUUS DIGITAL FORD CODE READER (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

 

[f8tlfiveo]

got it running the iac valve was bad, swapped one ove from my bros 93 gt, and it was fine so i went to autozone. its great having a donor car!!! thanks for your help anyway.