I have a 99 Ranger with the 3.0L Flex Fuel engine. It has had the throttle body replaced under warranty once already. At around 49K miles the engine started racing between shifts. It is a five speed manual. It does not do it all the time. I have tried to put constraints on when it does it but I can't. It does it when it is cold (below 32F), when it is hot (more frequently when the ambient air is above 32F), when it is raining, etc. I can't predict when and where it will start doing it. I have had it in the shop and of course it will not do it when it is in the shop. If I turn off the ignition while the truck is rolling and the engine is at normal operating temps and turn it back on again the racing will stop sometimes completely. However sometimes it will start backup up again with the next shift. I can be driving down the interstate, get off at an exit and come up to a stop light and shift into neutral and the engine will be racing. Eventually it will return to idle but not in the 3 seconds that Ford says is normal. It is more like 10-20 seconds. I even had one of the service people drive it on a rainy day when it was doing it to make sure someone else at the shop could verify it.

I am at a loss. Other than this problem the truck is great. Any and all help would be greatly appreciated. I am desparate and am afraid to let my wife drive it cause in stop and go traffic it actually pulls the vehicle forward and if your aren't quick on the brakes you could crash. Yes, it will pull the truck forward if it is in gear.

If I knew some engineer at Ford I would send this to him/her but I don't so you are my only hope. It is really quite dangerous when it happens in city traffic.

Thanks for you help.

 

There is a TSB about this issue, #98-26-08. Here's part of it, hope it helps.

ISSUE: The Malfunction Indicator Lamp (MIL) may illuminate and Diagnostic Trouble Code (DTC) P0320 may be stored in memory on some vehicles. There may also be a high idle rpm (1300-2000) on closed throttle deceleration in Neutral or clutch depressed. This may be caused by the Powertrain Control Module (PCM) calibration.

ACTION: Reprogram the PCM to latest calibration level. This more robust calibration reduces deceleration air flow and reduces the possibility of high rpm with high limit hardware. In addition, the calibration error is fixed to reduce the possibility of unique driver action causing a false P0320 MIL code.

 

Thanks so much I will inform them and see if they are aware of the issue. If not I will let everyone know.



Bob H.

 

Well I checked with the dealer and they have already reset and recalibrated the PCM each time it was in. :-( So I guess I am back to the original problem. I think it is clearly electical or a software error but I do not know how to track it down and apparently the dealer does not either. I wish I could talk to a Ford engineer.

How reliable are the 2002 3.0L engines??


Bob H.

 

If they did the recalibration they are required to place a modification sticker next to the emissions control information decal, might want to check for it. ALso it could be a IAC problem. They should be able to fix it but if you can't seem to get this SAFETY problem corrected you might want to bring up a SAFETY concern and lemon law with someone higher up at the dealer or contact the divisional people listed in your owners manual. Good luck and I hope you get this resolved.

 

If I were to start replacing parts where would you think a good place to start might be? The PCM?

Thanks

bob Hunchberger

 

I don't like replacing parts without knowning they are defective, it can run into big $$$. The IAC, idle air control valve is how the PCM controls the idle speed, a vacuum leak could cause an idle problem, the PCM is $$$ to replace and is probably a non-returnable part.

 

I had a similar problem on my '94 4.0L. It turns out that my floor mat was on top of my throttle pedal and causing my engine to soar up to 4000 rpm between shifts!
:-X11

 

I checked that first. The engine revving is intermittent. I can't predict when it will happen. The ambient air can be above 32F or below 32F and it will do it. It can be raining or dry outside and it will do it. It almost always does it after warming up but occassionally it will do it at engine startup but when that happens after running a bit through the gears it settles down. But there is no guarantee that the condition will not appear later in my 40 min drive to work. Thanks for your input.


Bob H.

 

I had that same problem a couple of months ago with a 98 3.0, with 75000 mi. I thought the same thing you guys are saying. Computer and such. What it turned out to be was the throttle spring. That little coil between your throttle body and your intake. Road debris, in my case mud from 4 wheelin', gets into it and was causing a hang up.

I had the same problems you were talking about. The space between the intake and the throttle almost seems to lend itself to dirt and debris. Mine was taking off as soon as I was letting off the clutch. It was like having cruise control. I wouldn't even have to hit the gas on the interstate, and the RPM's would top out at 4500 in neutral.

What I did was take some carb cleaner, not WD40, and spray it on the entire throttle system; cable, coil and all, and I took the air intake tube off of the truck and sprayed the cleaner into the intake to clean that out. Like I said, it looks like there is too much space between the throttle and the intake, a lot of stuff can get in there. Since doing that I haven't had it happen again. Seemed to clear it up good. My light came on telling me there was an engine problem, but disconnecting the battery will get rid of that and reset your computer. But don't worry, if you really have a problem your light will come back on.

Hope this helps.

 

you may have something there. did yours continue to rev after shutting off the ignition? If i turn off the ignition the revving stops but it may start again if I drive it. There in lies the possible link. To drive it and shift it I have to depress the gas pedal which is connected to the throttle cable. let me check that out and see. Boy I hope it is just a throttle cable problem.

I called Ford's customer relations today to log the issue and see what resources they could bring to bear on the problem. they may not have to get engaged if it is only a throttle cable.

Thanks for your help. Keep you posted.

Bob H.

 

When I started the truck, the engine would jump right up to 4500 RPM. Clutch in shift into first, the truck would just take right off...I didn't even have to push the gas. Every time I would push in the clutch the RPM's would jump right up to 4500 and then return to about 2000 when I put it in the next gear.

When I'd shut the engine down, it would run for a few seconds and then violently shudder to a stop.

Like I said before, check your air intake system...change your filter, clean out your hose, and lube and clean all moving parts associated with it. That coil spring under your throttle cover might be the most important. Regular choke cleaner will do the job. Still haven't had reccurrence of that problem.

 

 

I have the same problem with my 2002. Throttle seems to hang up while clutch is in for shifting or stopping at a light. Turning the a/c off or quickly loading/unloading motor with the clutch seems to bring engine rpm down to idle most of the time. For instance, if I shift at 2,500 rpm the engine may run up to 3,000 before I get into next gear.
I have checked for codes. None. I have sprayed everything off with carb cleaner. No help. I have cleaned the throttle plate. No help. I have looked for vacuum leaks but didn't find any. I checked the cruise control and ti seems to be releasing. I set the cruise and then canceled it with the off switch and the truck slowed normally.

Any ideas?

 

Hunch, you say that the engine races when you shift. What are talking about in terms of RPM's?