hesitation when hitting gas while driving

[strattoc]

I've searched and looked through the checklist but I'm having a hard time finding anything because I feel like this issue may not be so common.

I recently replace the IAC, TPS and inlet air temp sensor. Put a 70 mm tb and egr plate and explorer upper and lower. I recently went through and fixed quite a few vacuum leaks and set the timing at 10*. My problem is that it will idle fine and take off fine but if its rolling and I try to ease into the gas it takes like 1 or 2 seconds to react and a couple of times it has backfired as if the timing was off, I cant remember if its too far advanced or retarded when it backfires. If I go hard on the throttle its fine but when I ease into it this happens everytime. I also took electric cleaner to the salt and pepper shakers and any other connectors I could easily get too. Also I did the base idle reset thing. I'm stumped and dont really want to throw more sensors at it to fix the issue.

 

[strattoc]

anyone have a clue?

 

[LX302]

Did you have the spout connector removed when you set the timing?
Replace the Rotor and Dist. Cap when you replaced the other sensors?
How are your plugs and wires?

 

[strattoc]

Yes I removed the spout, timing is at 10*.

I changed the cap and rotor with the MSD brand and an MSD streetfire coil. I have some Ford Racing 9mm wires on the way but the ones on there still look good.

I'm wanting to say my issue is transmission related, I have an AOD and it has no problem when you first take off but when its in the higher gears it does it, so I'm going to try and check/adjust the shift down cable because it didnt really do this until I changed the TB which makes me think the cable might be out of adjustment and when you first give it gas at a roll it cant decide whether it needs to shift down or stay in the gear.... just a hunch.

 

[jrichker]

Dumping the computer diagnostic codes on 86-95 Mustangs

Revised 18-Mar-2011 to advise differences in code information for engine running and engine off codes.

Here's the way 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.

Be sure to turn off the A/C, and put the transmission in neutral when dumping the codes. Fail to do this and you will generate a code 67 and not be able to dump the Engine Running codes.

Dumping the Engine Running codes: The procedure is the same, you start the engine with the test jumper in place. Be sure the A/C is off and the transmission is in neutral. You'll get an 11, then a 4 and the engine will speed up to do the EGR test. After the engine speed decreases back to idle, it will dump the engine running codes.

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.


WARNING!!! 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.

Some 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.
Or for a nicer scanner see http://www.midwayautosupply.com/p-7208-equus-digital-ford-code-reader-3145.aspx– It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

 

[strattoc]

I have performed this procedure before I changed the TPS, I have not been able to set the TPS because I dont have a digital multi-meter, I just have a tiny cheap-o one, which I use for koeo and koer. Last time I got 63 and 97, which is TPS low-voltage and not complete test.

I adjusted the shift down cable which made it shift better but hasnt helped my issue.

 

[jrichker]

Check out eBay for a DMM (Digital Multi Meter). I got a nice Triplett DMM for less than $20. You are going to need a good meter if you spend any time fixing things.

 

[strattoc]

UPDATE: I purchased a digital multimeter set the TPS and did the KOEO and I think I got code 11, its hard to tell because I dont know which voltage reading setting is easiest to use for that. But I was able to fix my problem, it was quite simple, I noticed the vacuum line going to the MAP was collapsed, I never noticed it before because it was only doing it after the engine was warm. So I purchased some fuel line because it seems that no one has decent vacuum hose and problem solved, no more bump when I give it gas and no more timing back fire. I love driving my car again!