[Bob Lincoln]

The only time I got near 40 mpg on my 5-speed TBI Daytonas is when the national speed limit was 55 mph and I was traveling on long highway trips with cruise control set. I averaged 40 mpg from MA to FL and back. Later from MA to VT where the speed limits were 50 and 55, averaged 38. But lifetime average was 34 mpg, and now with my 93 Daytona I can't get better than 32 mpg. I blame it on the ethanol gas, which is all 10% in this part of the country.

 

[B10alia]

I'm not quite sure what's going on here either. Unless there's something seriously wrong somewhere, your flywheel should be in "agreement" with the timing marks. If the marks line up correctly, the engine is timed correctly, there's no other way to it. From what you're saying, it sounds like there's a discrepancy between the flywheel and the timing marks. Also, if you see what seems to be an idle adjustment on the TB that holds the throttle blade partially open, (like an idle adjuster on a carbureted engine) DO NOT TOUCH IT. It is not an idle adjustment, it adjusts how much air goes through the throttle body at idle. It has absolutely no effect on idle speed unless it's messed with and left in a bad position. A throttle body cleaning, particularly the AIS pintle, might help, but I seriously doubt it. What happened with the electrical fault you mentioned?

 

[Bob Lincoln]

With the flywheel, what he did was line up the 3 gear marks while the ignition timing mark was off of TDC by a few degrees. So when he went to set the ignition timing, it was not indicating the correct reading, because the cam and intermediate shaft were now off a little. He had to take the belt off, turn the flywheel to TDC, then align the other two shafts to the crank gear's mark.

 

[pSun]

Yes, I did what Bob said. I will go through the throttle body and AIS when I swap in the new head.

It is now running well! Great idle, very smooth accelleration, nice torque at low rpm. After everything was sorted out, I, can really fell a big difference with the A/C disabled...even the exhaust note.

B10alia; it still stikes me as hard to believe, but the coil just start shoting to the strut tower through the coil wire boot. I just happened to have a set of replacement wires ready to install. I tried the new coil wire first, that stopped the short. Then I installed the rest of the wire set. Has not been a problem since. SWEET!

I don't want to jynx it but the car is really feeling super these days. Yesterday I had to run several out of town errands and was and found myself truely enjoying the drive.

The coil was SHORTING to the strut...not "shoting". Sorry.

 

[Bob Lincoln]

I replace wires and dist cap every 30K miles.

 

[B10alia]

How is your idle RPM currently? Was that issue resolved?

 

[pSun]

The idle is good when in gear, while in park it is a little higher than it used to be. I could have sworn that I had read a proceedure to reset /restore the original idle. For now it is acceptable

My dash tachometer hasn't worked for the last 20k miles. I am going disconnect the sensor and try the squeeze trick.

I did manage to get the underdrive pulley in today. It feels like a completely different car. I reverified the timing while installing the pulley, it is currently spot on.

Thanks again for all the help!

 

[Bob Lincoln]

My dash tachometer hasn't worked for the last 20k miles. I am going disconnect the sensor and try the squeeze trick.

I have no idea what a squeeze trick is, but most likely, you have a tachometer drive board that is a daughter card off the main instrument board. It may have failed or come loose.

 

[pSun]

I was informed that the most probable cause for the tach failure is the wiring connector to the sensor on the transmisssion and that I should squeeze the female portion of the connector to correct the signal loss.

I performed this today but must wait until I have the dash back together to test it. Since the dash is apart I will check the tach's connectors before I put it back together.

 

[Bob Lincoln]

The tach does not get its signal from the transmission. It comes from the Hall effect sensor in the distributor. Since the engine is running, the signal is at least making its way to the computer.

 

[george w]

The sensor at the transmission is for the speedometer, not the tach. If the tach is not operating then Bob is right on about checking the plug in tach board on the back of the instrument cluster. You may need to just clean the contacts to restore the tach operation. If that doesn't do it then you may have a bad tach movement. Also make sure that the connecting plugs on the back of the instrument cluster are fully seated. It wouldn't hurt to unplug and replug the connectors to reseat the contacts and dislodge any corrosion or oxidation that has built up over the years, The tach movements themselves rarely fail, however havng said that, these cars are well past their design life now so ANYTHING could be expected to fail.

 

[B10alia]

I seriously doubt your tach is blown. These cluster boards are notorious for having bad solder joints in them, so that might be a good first place to start, touching up all the joints with an iron.

 

[Bob Lincoln]

These tach boards have a known design flaw that drains the car battery excessively and overheats a zener diode on the tach board. So there could be a failure there. I worked out the schematic and rewired mine to eliminate the flaw.

 

[pSun]

Upon inspecting the instrament panel and tach board, I found no harm in touching up the prvios solder work and that 1 resistor on the tachometer board could use a bit exrta solder.

I will be plugging this in to test ASAP. I can live without the tach, it is an automatic. I want to teach my daughter the relationship between the engine rpm and when to shift, otherwise I probably would have written it off. Fingers crossed.