[Jack]

I am having a problem with rough running, and stalling of my ´88 in warm weather and at highway speeds--usually around 1/4 throttle. It sometimes stalls at when idling too. I have tuned up the car and changed the fuel filter, with little or no result.

Anyone have similar problems?

 

[rascal]

Jack: Check and/or replace the TPS. Throttle Position Sensor. My car acted in similiar ways and had that replaced. She runs fine now. I have an 88.5 LX w/ 148k on her. The TPS is under the air filter housing on the LX model. Check your HAYNES manual for a more detailed removal. Hope this helps.

 

[Pimp_scort_89_GT]

A bad TPS sensor would cause some rough engine conditions, But it should cause them any time the Trottle gets to the bad spot in the sensor, i.e. during acceleration too. I´d try sitting in neutral at idle and slowly raising your RPM until you find a spot that starts to give you trouble. If it is smooth all the way to how ever comfotable you feel like reving it to, the TPS is more than likely not the culpret. But if it does hesitate say everytime you pass 2000-2500 RPM then I´d say go ahead and try a new one. One thing that is notorius for giving drivability problems on the freeway is the Ignition Module. Ford actually has a lawsuit against them concerning their TFI Ignition modules. People are claiming Ford new they were poor quality, and should have recalled them. I actually recived a letter in the mail about this. But it seems they tend to over heat every now and then, the internal component start going bonkers. So if you try the TPS and it turns out ok, I´d check the ignition module next. If you don´t know, it´s the part bolted to the side of the distributor. I believe most Pep Boys or Auto Zones have testers, and will test these for free, but what ever you do, try to avoid buying one from them. Because as shody as the Ford modules were, the aftermarket one are worse. I threw an Auto Zone TFI module in a Mustang one and it ran worse than it did before. But we put a Motorcraft one in and it straightened right up. So if at all possable go to the dealer and try to get one their. They might even have some special thing where you can get them for cheap, or even free (Don´t hold your breath) since they are up against a law suite.
And if it isn´t the Ignition Module, let me know, there are a number of places to go from there.

_________________

[ Edited by Pimp_scort_89_GT On Date 06-29-2002 ]

 

[rascal]

Yeah, I got one of those lawsuit letters about the TFI module on my Scort. I was going to replace it too when my car started screwing up but when I took it to the shop they said my TPS was bad. Jack: does your Scort emit black smoke from time to time when trying to speed up frm an idle? My did. Pimp is right abot the aftermarket module, go OEM from the dealer. I´ve learned that with my CV joints. The only thing Auto Zone has thats worth a damn is some small accessories and air, oil filter and oil. Alternators are a joke too. They might have a lifttime warranty but what good is it if goes out in six months and you have to stop what your doing to replace it again. After having to take the time to take it off, go back to Auto Zone (around here you wait a long while to get waited on, the South isn´t know for great quality service when it come to retail), then get home and put it back on, your better off getting a custom built one from a alternator shop that deals with them everyday. If you can afford it or knwo somebody real well, take it to a shop and let them check it out. They´ve seen problems like this many times and probably won´t take them long to find the problem. Let us know what you find.

 

[Pimp_scort_89_GT]

Good point about the alternantor. I got one from Checkers (a.k.a Shucks or Kragen in other parts of the US) It was when I first bought my scort and I didn´t think I´d be keeping it for too long so I didn´t care what I put on there. But never fail, once a month, almost to the day that damn thing would fry. I got pretty damn good at changing alternators on that car. After 6 or so months I finally realized I was going to be keeping the scort for a while, so I traded it in for a better on. I only had to change it twice so far. But I´m sure Motorcraft would be a much better deal. But For certain I wouldn´t buy an ignithion module anywhere else.

 

[Jack]

Thanks for the advice. Ihaven´t noticed any black smoke, and I actually have replaced the module about a year ago, thinking that was the problem. I didn´t replace it with a stock one, but then again I didn´t replace it with a crappy Autozone one either. I bought a Bosch one, which I hoped was a good choice. It didn´t seem to make much difference either.

I have a friend who´s brother is an engineer at Ford (he does paint and finishes unfortunately) who got me a technical service bulletin which describes "bucking and jerking at highway speeds". The Ford explaination for this is water/ice/salt buildup in the VAF. They suggest rebuilding the VAF (kit=$235) or replacing it altogether (about a billion $). This weekend I tried just spraying the heck out of it with carb cleaner--and that might have worked some. I haven´t noticed any stalling (at least this morning). The real test will be the commute home in the heat of the afternoon.

I agree with you on those discount autoparts stores. I once went into a Schuck´s in Seattle looking to buy a high volume oil pump for my Brothers ´70 Mach I. The counter guy asked me for what motor, to which I replied "351 Cleveland".
He flipped through his performance parts catalog with a puzzled look for a few seconds, then asked, "...now that´s a Chevy motor right?"
I chuckled thinking he was joking, but he just stared at me humorlessly. I knew I was in trouble at that point.
Luckily, after clearing up the fact that Mustangs are indeed made by Ford and that 351´s are in fact Ford only motors, he found he was going to have to order the part. I took this as my cue to leave, and wound up ordering one from Summit, which I should have done to start with.

I will let you know how my afternoon commute turns out.
Jack.