Intermittent Start and Poor Acceleration

95_MUSTANG_95 · 06-10-2004, 09:22 AM

I read with interest the MustangLover71 posts as my issue has similar symptoms. I have a 95 Mustang, stock. Exception is a K&N air filter.

I began experiencing problems with an occasional no start which was corrected by unplugging the idle air intake sensor, starting the motor and reconnecting the sensor. Recently I had no spark and replaced the ignition switch and she starts, but still has this occasional intermittent problem. When the intermittent start problem occurs I have a nice blue spark as tested at the coil and through a few wires (did not look at all).
Fuel pump has maybe 15k miles and always kicks on at key on. I don’t have a fuel pressure tester but, there is pressure at the rail. I have tested compression in each cylinder and it ranges between 120psi – 140psi with no bleed down. Plugs are Bosch Plat., wires are Motorcraft and both have about 15k as well. Where the wires rub on engine mounts and other brackets I have dressed them with electrical tape; one individual seems to think this is a bad thing, sighting that moisture will build up under the tape and kill the HV causing internal shorting. I have alot of static on the FM band of my radio which is an indicator of spark noise, among other things. These wires could be my acceleration problem.

I am planning to test and clean my injectors tonight. Any thoughts on how to test the TFI module, oxygen sensors and fuel regulator? Any other ideas on what to look at?

bigred90gt · 06-10-2004, 09:56 AM

Make sure none of your plug wires are touching each other. This has been known to cause some problems. Also, I would say ditch the platinum plugs and get some Motorcraft, or NGK (some people use Autolite also) copper plugs.

As for testing your TFI - Take it off, take it down to the auto parts store (I prefer Orilley) and have them test it. Its free. If your o2 sensors are bad, your check engine light should come on. I would recommend pulling your codes regardless of the check engine light being on or not.

Capri306 · 06-10-2004, 04:48 PM

Quote:

Originally posted by 95_MUSTANG_95
I began experiencing problems with an occasional no start which was corrected by unplugging the idle air intake sensor, starting the motor and reconnecting the sensor.

I'm not trying to be rude, but which-the-heck sensor are you talking about? There's a Mass Air Flow Sensor and an Idle Air Control Valve, but I'm going to assume you meant the MAF. If that's the case, your MAF is probably junk. Notorious for failing at somewhere around the 100k mile mark, and makes the car run lean usually.

I agree that the electrical tape is NOT a good idea for long term; instead, get a set of plastic wire separators, so that way the plastic is hitting the valve covers and not the wires.

One thing I'd like to know is that if the ignition switch was replaced, have you checked to see that the EEC module and the fuel injectors are getting power?

Also, crank it over a few times and then pull a couple of plugs to see whether they're wet or dry, and go from there.

95_MUSTANG_95 · 06-11-2004, 07:17 AM

My mistake. Was referring to the IAC (idle air control solenoid) not a sensor. The IAC is new and one day when the vehicle did not start I thought that maybe the new IAC was the source of my problem. So, I unplugged it and she started. Ever since then I have used the same trick and most of the time it works. This latest time it did not.

I have not checked power to the EEC nor have I checked the injectors as yet. I have all the plugs out to test the compression. Any other obvious method of checking for injector operation with the plugs out? It is pretty difficult to get your eyes low enough to actually see in the opening.

Took the TFI module to the local Ford dealer. They tell me there is a test for the older unit which is distributor mounted. My TFI unit is mounted in a big heat sink on the fender wall behind the MAF stuff. They will sell me a new one for $125. I am holding off for the moment.

PKRWUD · 06-12-2004, 02:15 PM

You need to replace your IAC, reset the ECM, and drive it for an hour. Then see if there are any codes. if you over-oiled your K&N, you probably have a dirty MAF wire which will need to be cleaned.

06-10-2004, 09:22 AM	#1
95_MUSTANG_95 Registered Member Join Date: May 2003 Location: Massachusetts Posts: 7	Intermittent Start and Poor Acceleration I read with interest the MustangLover71 posts as my issue has similar symptoms. I have a 95 Mustang, stock. Exception is a K&N air filter. I began experiencing problems with an occasional no start which was corrected by unplugging the idle air intake sensor, starting the motor and reconnecting the sensor. Recently I had no spark and replaced the ignition switch and she starts, but still has this occasional intermittent problem. When the intermittent start problem occurs I have a nice blue spark as tested at the coil and through a few wires (did not look at all). Fuel pump has maybe 15k miles and always kicks on at key on. I don’t have a fuel pressure tester but, there is pressure at the rail. I have tested compression in each cylinder and it ranges between 120psi – 140psi with no bleed down. Plugs are Bosch Plat., wires are Motorcraft and both have about 15k as well. Where the wires rub on engine mounts and other brackets I have dressed them with electrical tape; one individual seems to think this is a bad thing, sighting that moisture will build up under the tape and kill the HV causing internal shorting. I have alot of static on the FM band of my radio which is an indicator of spark noise, among other things. These wires could be my acceleration problem. I am planning to test and clean my injectors tonight. Any thoughts on how to test the TFI module, oxygen sensors and fuel regulator? Any other ideas on what to look at? __________________ Lets turn and burn.

06-10-2004, 09:56 AM	#2
bigred90gt 2 Stangs in the Stable Join Date: Apr 2002 Location: Baytown, TX Posts: 1,209	Make sure none of your plug wires are touching each other. This has been known to cause some problems. Also, I would say ditch the platinum plugs and get some Motorcraft, or NGK (some people use Autolite also) copper plugs. As for testing your TFI - Take it off, take it down to the auto parts store (I prefer Orilley) and have them test it. Its free. If your o2 sensors are bad, your check engine light should come on. I would recommend pulling your codes regardless of the check engine light being on or not. __________________ '90 GT Under construction Best E.T. = Fast @ High Speeds - OK So I Lie. So What!!! 04 F-150 STX 4.2L 5 spd Rice Haters Club Member #128

06-11-2004, 07:17 AM	#4
95_MUSTANG_95 Registered Member Join Date: May 2003 Location: Massachusetts Posts: 7	Sensors My mistake. Was referring to the IAC (idle air control solenoid) not a sensor. The IAC is new and one day when the vehicle did not start I thought that maybe the new IAC was the source of my problem. So, I unplugged it and she started. Ever since then I have used the same trick and most of the time it works. This latest time it did not. I have not checked power to the EEC nor have I checked the injectors as yet. I have all the plugs out to test the compression. Any other obvious method of checking for injector operation with the plugs out? It is pretty difficult to get your eyes low enough to actually see in the opening. Took the TFI module to the local Ford dealer. They tell me there is a test for the older unit which is distributor mounted. My TFI unit is mounted in a big heat sink on the fender wall behind the MAF stuff. They will sell me a new one for $125. I am holding off for the moment. __________________ Lets turn and burn.

06-12-2004, 02:15 PM	#5
PKRWUD Junior Member Join Date: Mar 1999 Location: Ventura, California Posts: 8,981	You need to replace your IAC, reset the ECM, and drive it for an hour. Then see if there are any codes. if you over-oiled your K&N, you probably have a dirty MAF wire which will need to be cleaned. __________________ Webmaster: Rice Haters Club Jim Porter Racing Peckerwoods Pit Stop Support Your Local RED & WHITE!