Here's an interesting problem I encountered yesterday.... after sitting out in the sun and 80-degree heat all day yesterday, I noticed something weird happening to my 88 max. I drove it a short trip to the hardware store, and when I came back to the car I noticed both cooling fans were running at full speed. when I started the car, the idle speed stayed at right around 2,000 RPM and wouldn't drop. when I hit the gas, it would rev, drop down below 1,000 and then rise back up over 2,000. if you kept the gas off, sometimes it would rise and fall all by itself. It wasn't due to overheating, because the water temperature gauge stayed just under halfway. I'm still having this problem even after it sat overnight. I turned the idle speed way down and it's still up at around 1,500 RPM. I checked and adjusted the timing but that made no difference either.

So now I'm lost. does anyone else have any ideas? the only thing I can think of is check the diagnostic lamps on the ECU to see if they indicate a problem. I can then look it up in the FSM. but other than that.... I'm out of ideas. with the idle turned completely down and the timing readjusted to where it's dead on, it still idles high, just around 1,500 RPM.

Thanks

Dan
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Yeah, definitely check the ECU, you probably have a bad Throttle Position Sensor (TPS).

-C-

 

daahh... I checked the ECU and it returns the normal 5-red and 5-green sequence. I'll keep trying though....

 

Your FICD could be bad, or your throttle cable maybe getting caught on something. I would check all the cables including the ones that go to the ASCD. Something like that is a sign of probably a sticking throttle.

S

 

I dunno but I tried turning the idle completely down and it's still around 1200-1500 at idle, and now it runs like **** on the highway, doing a lot of sputtering. I'll go outside and look everything over again....

 

Well, turning the idle down isn't going to fix a sticking throttle. Have you checked it out? I would also make sure your FICD is working alright, might have to test it and see. As for the sputtering, I would check AIV, make sure its not putting water into your airbox. Also you might want to also check the BCDD and the vacuum hose going to it. When is the last time you did a tune up on the car?

S

 

checked the throttle cables, even for the cruise control and nothing seems to be sticking. I'm not sure how to test the FICD, AIV or BCDD. not even really sure what they are and/or what they stand for. The car was tuned up just over a year ago and it got new plugs, wires, cap, rotor, and fuel filter.

I looked the problem up in the FSM under the section "Fast idle - before warm up" and it gave a list of possibilities. the first was the ignition timing, which is dead on according to my timing light. then it suggested a leak in the air duct but I didn't see one off-hand, but I haven't throughly checked that. after that was the air regulator but that seems to be ok. then it suggested removing the vacuum hose from the pressure regulator and seeing if there is an improvement. there wasn't. after that was the idle-up solenoid and the FICD solenoid.

the air regulator circuits all tested OK from the ECU to the regulator.

here's where I got caught up. I went to the page that covers checking the idle-up and FICD solenoid (EF&EC-113) and the first step is to check for battery voltage at terminal 'b' and ground with the ignition switch on. there is no voltage there at all. I don't know how much of a problem that creates.

that's where I stand and then it started raining out, so I packed it up and I'm going to try it another day.

 

Yeah, the testing of that stuff would be with a voltmeter and what not. Hmm, I'm gonna have to reference my FSM when I get home about the idle-up solenoid. Have you tried disconnecting the harness to it and running the car? I'm also kinda wondering though if the air regular shutter is getting stuck open or the BCDD valve is stuck open. They can test fine and still have problems. Also did you pull off the intake hose going to the throttle body and check to make sure that nothing is causing it to stay open? I would go in there and do a really good cleaning and see what the yield (car could probably use a TB cleaning anyway.)

S

 

tried disconnecting the idle-up solenoid when I tried turning down the idle. the only difference it made was it would idle around 1100-1200 instead of the usual 1500-1600 that it's been doing.

I haven't checked the intake hose yet, all it's been doing here is raining.

 

the intake hose... I'm assuming that's the thick black one coming from the air cleaner, right?

 

Have you solved the problem? I really want to know because my car just got the same problem too.

 

nope.

I checked all the vacuum lines, and a few things from the manual, but I'm still lost. it's usin a lot of gas, so I need to get it fixed soon. even my mechainc is lost.

I'll let you know if I find anything. I wonder if it has to do with the heat. it didn't do this until I used the air conditioner for the first time this year.

Dan

 

still lost. I'm having a repeated problem now with the rotor actually coming off the distributor shaft. the screw would back itself out while I'm driving and the car would just sputter...and backfire....and sputter...and then I'd smell rotten eggs.... then it would just cut out. it happened 3 times today.

once again, if I find anything, I'll let you know. I tried cleaning out the air intake but that wasn't much help. that engine gets so hot that it needs to cool down practically overnight before I can even begin working on anything.