I agree the Cats are probably pretty unhappy, but I'm not sure about one or more injectors. That would feel more like a miss. It's more like whitestx said, like running into a big wind. If I had a carb I'd be rapping the float bowl to free up a stuck float. Too bad these cars don't come with a Ctrl-Alt-Del combination on the door pads.

I'm going to follow the EGR thread and see if that helps, then we'll see if the Cats are toast.

Bill Mounteer
Calgary, Alberta

 

My dad had a 92 crown Vic and even though it was a different engine management system (eec vs OBD) it had the same problem. It surged like no ones business. Finally had a good tech sit and beat on it and he remembered reading about a problem with the EGR tube that connects both of the heads together. What happened was that the stress of the heat cycles eventually cracked the tube. No codes, no tune-up to fix the problem, no sensor ails; It just was a stubborn and surging beast. After the new tube, it ran like a champ.
I would also worry about your catalytics getting all that raw fuel. They can also be a source of your problems. If they close up, the motor will literally not run at all. (I have seen this happen on a GM, started it up and moved it at a garage, next time it would not even crank over from the back pressure, removed the catalytics and it ran fine, go figure) This may be part of you starting problem, try removing the cats (temporairly) and see if it starts and idles correctly before removing that EGR tube. Cheap tech check and makes lots of noise.

Brian

 

My 99 F150 has the same problem. I took it to the Ford dealership and they cleaned the EGR assembly and charged me $207.00. Still surges badley when driving down the road and every now and then it will not idle at start. I wish I had some answers. I wonder if it isn't a fuel problem. It does it worst when I accelerate at higher speeds. I don't know but I wont be taking it back to a Ford dealer. I can find plenty of people to mess up my truck and take my money. Any ideas would help out.

 

Bill,

While the tech is there cleaning the EGR ports have him check the KOEOff voltage on the TPS(throttle position sensor). It should be under one volt (0.98 volt would be optimal). If it is over 1 volt it could be causing your problem.

Good Luck,

Bill

 

I suspect my mechanic's code reader isn't picking up any or all codes the PCM may be kicking out. Plus I'm starting to think he may have bitten off more than he can chew, this problem seems to be more complicated than the typical day to day run of the mill type problems he is used to dealing with.

I'm more or less convinced the problem is that something is plugged up. My driving habits tend to support this idea. I bought the car new in Aug '95 and it now has just 50,000 miles on it, so deduct about 5,000 in highway trips and I'm left with an average of about 15 miles a day of city traffic. It takes about 10 minutes to go from my house to my office so I doubt the car even gets fully warmed up, especially in the winter. Knowing this I make sure the oil and filters get changed often, but fouling of EGR passages is something that only more highway miles would help. My wife’s ’93 Taurus suffered the same problems caused by not driving it enough. Her car was regularly serviced by Ford and even so after 65,000 Km (about 40,000 miles) the 3.8 V6 was sludged up enough that the engine seized and it cost nearly $3,500 for a short block. Her car now has 62,000 miles, which works out to only 17 miles per day. Her main bearings had virtually no bearing surface left.

Maybe I should just park all the cars and buy some mountain bikes.

Thanks again for all the help, this is a great board.


Bill Mounteer
Calgary, Alberta

 

As a summary for guys with similar problems following this thread here's what's been done.

1 .. Vacuum lines checked twice and sprayed with some leak detecting spray. No leaks.

2 .. IAC (Idle air control) replaced. No change.

3 .. MAF (Mass air flow) replaced. No change.

4 .. EGR (Exhaust gas recirculator) sensor tested and it's foam filter cleaned. No change. Manually operating the sensor does change engine speed so we assume it's working.

5 .. EGR cross tube between the two heads is clear and not cracked or split.

6 .. Replaced thermostat. No change.

7 .. Measure TPS (Throttle position sensor) voltage. It's within spec, 1.0 volt at closed throttle.

8 .. Checked VSS (Vehicle speed sensor) and it's within spec.

9 .. Checked fuel pressure, its 32 to 35 psi operating and peaks to 45 psi with regulator bypassed. Filter is new and flow seems to be Ok.

10 .. Unplugged many sensors and no codes show up. Mind you some like open vacuum lines, disconnected EGR would only generate codes while driving. However some of the temperature sensors should have kicked out a code fairly quickly but didn't. The problem is we don't know if a '95 ECC V will kick them out as quickly as say a 2003 engine would.

11 .. A couple of times we've disconnected the battery overnight to see if the problem was one the car "learned" while it had a plugged up IAC. It didn't seem to make any difference at all.

About the only thing we discovered is the transmission pressure regulator is noisy/faulty and needs to be replaced.

My next step is to get a Ford trained tech with a Ford code reader to look it over.

So if your engine is doing the same kinds of things, it's probably not any of the above.

Once I get it fixed, I'll come back to this thread and let you know what got fixed.

Thanks again for all the input, great board.

Bill Mounteer
Calgary, Alberta

 

As promised for all those that helped with their suggestions and to those with similar problems here's what happened.

I took the car to a friend at a large Ford dealership and he arranged to have the car done by one of the lead tune-up guys as an after hours project. He rechecked all the things we had discussed and found that the new IAC control was fubar. He replaced the IAC again and the car still wouldn't idle. Since there is a history of IAC failures causing damage to the PCM, we decided to get a used PCM to try out. Plugged it in and the car runs perfectly!! Even better, the used PCM only was $200.

So there's a factiod to store in the back of your mind, if the IAC dies and your engine still runs the same after installing a new one - look real hard at the PCM. The silly thing produces no codes, it just won't control the IAC as it should.

Thanks again for all the help, great board and great bunch of guys.

Bill Mounteer
Calgary, Alberta