running bad?????? June 06, 2007, 10:50:31 PM just dropped a used motor in and ran fine. now it sputters and the tach goes wild it boosts like normal, it doesnt overheat and it idles fine but when i get on it thats when it runs bad kind of like a boost leak but i check all of that . any ideas? Quote Selected
running bad?????? Reply #3 – June 06, 2007, 11:09:42 PM Quote from: mikesparks;152354its a 2.3l 5 speedyear of car and year of donor motor? Quote Selected
running bad?????? Reply #4 – June 07, 2007, 05:52:51 AM 85 motor from xr-7 and its in an 88 tc Quote Selected
running bad?????? Reply #6 – June 07, 2007, 10:29:32 AM , you kill an 85xr7, they are rare enough without killing them:beatyoass: do you have the donor?ON your problem, id check for vac leaks first off with a can of carb cleaner while at idle by spraying along various busy looking vac intersections.go ahead and pull codes while your at it as well, might tell you something.you might as well do a check on the whole enginefuel pres testcheck for real blue blue/white spark (no orangish yellow)check compressioncheck for less than a volt on the green wire of the tpscheck for greater than 4.4vdc on the tps green wire with throttle open widecheck to make sure the voltage on the tps increases smoothly as you read the green wire and it has no intermittant opens Quote Selected
running bad?????? Reply #7 – June 07, 2007, 08:05:01 PM start with the basicsCheck timing check connectionscheck for vacspoogee leaks Quote Selected
running bad?????? Reply #8 – June 08, 2007, 04:50:47 PM Quote from: jcassity;152455, you kill an 85xr7, they are rare enough without killing them:beatyoass: do you have the donor?ON your problem, id check for vac leaks first off with a can of carb cleaner while at idle by spraying along various busy looking vac intersections.go ahead and pull codes while your at it as well, might tell you something.you might as well do a check on the whole enginefuel pres testcheck for real blue blue/white spark (no orangish yellow)check compressioncheck for less than a volt on the green wire of the tpscheck for greater than 4.4vdc on the tps green wire with throttle open widecheck to make sure the voltage on the tps increases smoothly as you read the green wire and it has no intermittant opensthe body was bad Quote Selected
running bad?????? Reply #9 – June 10, 2007, 10:51:49 PM i think it might be the ign. coil because the tach is going crazy Quote Selected
running bad?????? Reply #10 – August 11, 2007, 01:25:25 PM Quote from: mikesparks;153269i think it might be the ign. coil because the tach is going crazy The tachometer normally looks at the "high" side of the coil, with the TFI being down stream from the coil to switch the grounded lead when it's time to. Coils don't normally fail just partially, and never have I heard of one idling good but runnig bad at higher RPM if the coil was shot. If they do start having problems, you can usually see it on the outside. (Quick check: Put the car in your garage at night, leave the garage door open (carbon monoxide), and start the car with the hood up. If you have ignition wire or coil leakage problems, you WILL see them) A coil is nothing more than a transformer designed for high frequencies as opposed to one used for power supplies on AC powered devices. The primary has a few turns, and the secondary has thousands. If I do my math right, the ratio turns out to be 1:5000 on the typical Ford ignition system, so that a 12V pulse on one side pops the top of the dizzy with 60KV. Drop the voltage 1 Volt due to bad connection at the coil or TFI, and you now have only 55KV going to the plugs. As you can see, a minor bad connection in the primary circuit (12V side) of the coil is gonna drastically reduce the quality of spark you get. If the car cranks good and idles good, chances are you don't have a coil problem at all. Since it's RPM related, my guess is a wobbly dizzy shaft causing problems at the PIP which is the little Hall Effect pickup inside the dizzy, or a TFI that's having some heating issues. Thia is a VERY common problem on the 3.8's and 5.0's but I don't know if it showed up on the 2.3's or not. On the 6 bangers and V8's the dizzy is mounted on the front of the engine and the TFI is dizzy mounted on our vintage cars. With the dizzy right next to the effluent hose to the radiator. HEAT. The fan's pulling air through the radiator straight back on the TFI/dizzy, so MORE heat. This caused a huge law suit with Ford, yet, it still remained a ROAN call back on the cars. If one demonstrated driveability issues after getting warmed up, the TSB mandaged replacement of the dizzy and TFI with a remote mounted TFI. Search out TFI in here, and you'll find some pretty cool mods to relocate the TFI to a cooler location. Some even come complete with pics and instructions on doing the mod yourself. I plan on doing this mod as soon as I can get to a yard and pick up a heat sink from an F-150. My 86 3.8 gives me grief after it warms up, but doesn't throw a single code. This usually indicates some sort of ignition issue, for which there is VERY little diagnostics in the EEC-IV. EEC-V or EEC-VI on the other hand ....... Unfortunately neither EEC-V or EEC-VI will work on our old buzzards without some pretty major changes to the wiring and probably putting a late model engine and drive train in. Quote Selected
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