CFI Engine Racing

[Nick]

My '85 Continental has gained the ability to maintain speed on its own. In neutral or park, the engine races, regardless of whether the engine is warm or not. Any ideas on the cause? The engine light isn't on so would there be any codes to pull?

[Fordace]

Hi Nick,

Have you checked the fast idle linkage on the passenger side of the CFI unit for binding, or a broken return spring on the fast idle lever and such, it's the small spring on the linkage in front of the TP sensor. Other than that. I would disconnect the throttle cable and kickdown cable and see if it returns to idle when warm...you should check the vacuum motor on the other side too, see if the piston is returning when disconnecting the vacuum source...

[pro-five-oh]

How is that LSC exhaust conversion thing coming? Mine has a clogged muffler and sometimes when the muffler leaks (welds around the tailpipe) and gets louder...the motor idles perfectly. When the muffler is quiet, it always races. Maybe its something to do with the barometric pressure.

I donno why a backed up exhaust causes this, but it certainly does.

[Fordace]

PRO, do these year cars have a BMAP or a MAP?......

I can't remember....:confused:

[LSRX101]

My '85 Continental has gained the ability to maintain speed on its own. In neutral or park, the engine races, regardless of whether the engine is warm or not. Any ideas on the cause? The engine light isn't on so would there be any codes to pull?

Hey Nick, The most common cause of this concern is a failed heater in the CFI fast idle spring. It's in the round housing on the left side of the TB called a thermostat housing. The heater fails and won't let it drop to cuirb idle. You can bypass it by rotating the housing IIRC counter clockwise about 1/2 turn. You won't have fast idle for cold starts. If you want to make it work properly, the "thermostat housing" is about $40. PM me for proper procedures to adjust it if you decide to fix it.

[pro-five-oh]

PRO, do these year cars have a BMAP or a MAP?......

I can't remember....:confused:
99% sure its a MAP. Its that thing wedged between the coolant recovery tank and the inner fenderwell.

[Fordace]

yeah Pro, I know where it is, I just didn't know if it had a vacuum source or not....testing my memory on that year model for sure

[pro-five-oh]

LOL, I can't remember either. :(

[gadget73]

should be MAP, its actually the same sensor the SEFI engines use IIRC.

[Nick]

Thanks for the help guys. I had checked the throttle linkage and cable thinking they might be sticking, but they seemed OK. I didn't think of the fast idle system. I'll try and check out what you mentioned and report back. There is a small, white "can" by the throttle cable and under the air cleaner on the driver's side that is visibly broken, but it's been like that for a while. I never got around to replacing it. It's vacuum related and it's attached to the throttle linkage if I remember right. Any clue what it is?

By lengthening the O2 sensor wire by soldering in an extra length of wire, I didn't do anything that could throw the sensor off did I? In other words, is the sensor that sensitive to resistivity in the wire?

Pro, the exhaust has been done, but I had to go back in and replace a header gasket that failed (I think my header bolts loosened up) and tighten up a leak. They never get the header to collector joint right on the driver's side for some reason. They did the same thing when they replaced the collector pipe when I had the stock Y pipe. Sigh... Overall, I'm quite happy with the results and would recommend it to any other Continental owner. It got me power right where I need it, in the midrange so I can merge and pass safely. I'm curious to put it on a dyno to see what the exhaust gained. It won't make the car an LSC, but it's definitely an improvement.

It also ditched the POS boat anchor manifolds that came on the car. I think I saved 30 lbs or more losing them. Had I known that HO CFI cars had a unique manifold with a hot air intake baffle/shield, I might have tried to find a set to use on the car, but regular HO manifolds work fine. You just have to let the foil pipe hang down by the exhaust. That hot air intake system made for quick warm ups in the cold New England winter. I wish they brought it back.

[pro-five-oh]

Hmm, good info. I doubt that the O2 wiring made the difference. I haven't seen that white can you speak of (its not on my 1983) but that could be it.

I also vaguely remember that the EGR combined with the exhaust leak I spoke of being the problem. Inspect the EGR for busted vac lines too, can't hurt!

Did you run a code scanner on it?