hesitation at cruising speed

[KENS89LX]

My 89 has a hesitation at cruising speed, well I don't know if hesitation is the right word but anyway its like it surges but under wot it does'nt do it, I was told a piece in the distributor can do that. If any one knows about this inform me please, I'm sure someone will on here cause this site is AWESOME!

 

[88mouse]

What all mods do you have done to the car?

 

[KENS89LX]

stock bottom end, gt-40p heads, e-cam, stock intake 76mm throttle body

 

[88mouse]

Did it just start? Friend of mine had the same probablem, we put a new ACT in it, and that fixed it.
BTW you really need a different intake.

 

[KENS89LX]

stock bottom end, e-cam, gt-40p heads, stock intake with 70mm throttle body, 76mm c&l maf.

 

[KENS89LX]

Sorry about the repeat.. yea it starts and runs fine as long as it isnt a steady cruising speed

 

[Fett]

I had the same problem and it turned out to be my EGR valve.

The easiest way to tell is something you can do in five minutes. Go unhook the vac line to the EGR valve, place the vac line on the closest bolt that holds the AC accumulator to the firewall, this will plug the vac line so you don't have a vac leak while testing this. With the vac line unplugged from the EGR, take the car for a drive and try to recreate the problem.

That is what I did and I noticed right away that the surging/hesitation I had at crusing speed was gone.

 

[SMOKEDYA]

My buddy with an 89 is having the same problem! Is it around the 2000 RPM mark? His is. peace



john

 

[ebk06]

I have an 87 and one of my friends has a 86 and the other and 85. At cruise speeds we all have a surge......feels like the car just loses all power for a split second and then drives fine. All the cars do it at about 2000-3000 rpms at cruise speed. We all assume its because our old injectors may be dirty from 20+ years worth of driving. Ive got almost every sensor on the engine replaced and it still does it so im leaning toward injectors.

 

[2000xp8]

Give the car a tune up, you probably have burnt spark plug wires

 

[jrichker]

Quit guessing and do some diagnostic work.

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 http://www.troublecodes.net/Ford/

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.

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

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.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 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 http://www.midwayautosupply.com/pc-7208-90-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.