vobs

Last night I was messing around with my idle and I grounded the wrong wire. I grounded the wire that is supposed to be used for attaching the external tachometer. Yeah I know, I'm an idiot. Anyway now when I drive it I get no a very slow response from the accelerator pedal. I can slam on the gas and it will accelerate very slowly. I noticed that the tachometer wire runs into the leading coil, so I checked the resistence on the leading coil (.4 ohms) and the two coils on the trailing coil (.6 and .6 ohms). What did I do????? Please help, I need to get my baby working normally asap. What else can I check?
Matt

SpeedRacer

hmmm...you may have fried something on the ECU...its located under the passenger side floormat. Take a look at her and see if you can any burnt spots.

vobs

I have all of the carpet up and the metal plate over the top of the ECU removed. Can I take the cover of the ECU off with out any problems? Do I need to disconnect the battery first? Anybody with ECU experience help me out. Thanks ahead of time.
Matt

RXTASY1

YES!!! Whenever you work on something electrical in your car, disconnect the negative terminal on your battery.
You might also check the TPS, and the trailing coil.
The tach. works off the trailing coil.

Agent_D

iTrader: (2)

if its the ecu i have like 2-3 extras for 86-88 if you need one

vobs

Well, the ECU does not appear to be burnt at all anywhere. Should I verify that each lead is operating at the correct voltage? I have the factory manual layout for an '88 (close enough mines an '87) and approximate voltage listings for ignition on and at idle. Can I check each one individually with my volt meter by shoving the probes in the back of the connectores? Or since that the ECU is not burnt should I not go through this extra work? Here is what I am wondering. There are five wires coming off of the leading coil. Two of them go into the other part of the coil. One of the wires is the tachometer lead, and the other two seem to go to the ECU. Is this correct? Or is there some component in between the coil and the ecu that I should also check. Because if it goes straight to the ECU, wouldn't the only things that could have be affected by my grounding the wire is the coil and the ECU? The coils resistence checked out O.K. Help me please, I must get my baby to work right!!!
Matt

HAILERS

How about just a shadetree check out. Leave one of the lead plugs just barely attached to the plug, start the engine and while it runs , and making sure YOU are not touching the car, lift the plug wire a small distance from the plug and see if it is arcing. Or you could remove one of the lead wires from the coil and just lightly lay it in the bore and start the engine. While running move the wire a short distance(1/8 th inch or so) from the coil and see if it sparks. Sounds to me like the trail plugs are the only ones firing. Lead coil up front , trail coil near the master cylinder. Got a timing lite. Forget the above and just check the lead timing. If it is there then check the trail timing. Gotta admit I am just a little confused on what wire you shorted out. Like the above post said, the tach goes to the trail coil. Any rx will run just fine without the trail plugs working. Never miss a beat. Just miss the tach.

vobs

The tach wire I am referring to is the one that is used if you would hook up an external tach for ignition timing purposes. That is the wire I accidentally grounded. On my car the wire is near the initial set connector and the ecu check connector by the leading coil. It is actually attached to the leading coil on my '87 N/A. Hailers, I see what your trying to get at and I think you are on the right track. But I have never checked any ignition timing and I need to go buy a timing light. I was looking through my haynes manual at the timing process and it says that you need to adjust the the crank angle sensor if there is a problem, is the adjustor just underneath that black cap that is held down by two screws? Also how do you "look" to see if there is a spark when there is a rubber boot covering the whole thing? Sorry if thats a dumb question. If the leading plugs aren't firing will simply replacing them solve the problem or will I have to replace the leading coil? Thanks for your help, please let me know, I need to get her running normal by tonight. Thanks.
Matt

vobs

I still haven't got my hands on a timing light, not one store has one on this side of town. I'll check some other stores later. But with the car running I tried to pull it back a little bit, but I couldn't push the rubber boots out of the way so I'm not sure if it sparked. What I do know is that while the car is running I can completely remove each spark plug wire from the leading coil and it does not affect how the car is running. Does this tell anyone anything? If the ignition system was functionin properly, wouldn't disconnecting the wires while running affect it in some way? Are my plugs, coils or wires shot? Please help, I need to get this fixed soon. Thanks ahead of time.
Matt

tims

may have shorted out the igniter in the leading coil pack. stop by a local auto parts store and buy an ignition spark tester. looks like a spark plug with an alligator clip on it. follow the directions on the package to see if you have spark from the leading coil (plugs at the bottom of the engine). if no spark you probably shorted the ignitor or the ignition driver in the ECU. try replacing the coil pack first usually can be bought at a salvage or pick a part for $10-$20. if still no spark then a new ECU will be needed. first find out if there is spark at the leading plugs.

HAILERS

If you take the wires out of the lead coils and just lay them to the side, and then start the car, the output spark of the lead coils will come out of the holes and find the nearest ground. I've done it before and you'll get a big crackling blue spark just a jumping around. Thats if the lead is putting out. Tim's idea sounds real good. Do not buy new lead assy. Junk yard.If you have a friend with a rx try swapping out the lead assy. Easy to do. If that does not do it, remember the above post that offered to sell you one.Have fun. Oh yes, the lead plugs are on the bottom and the trail plugs are on the top. They have an embossed T or L next to the spark plug hole. I know you know that, but what if........

vobs

Well tims I bought an ignition spark tester, tested one of the leads, no spark. As soon as I get the chance I am going to recheck them both. But I think the leading coil is fried. Now I'm trying to narrow down a leading coil, a used one that is. Thanks for all of your help, now if I could only get that darn idle fixed...
Matt

P.S. I'll let you guys know if a different coil fixes it, thanks again!

rx7_ragtop

Probably the igniter, not the coil.

Brad

vobs

Is the igniter the the grey metal box behind the coil, or is it somewhere else. Just curious, I have an ignitor and a coil coming in the mail so, let me know. Thanks.
Matt

ProPhotog

so if the leading igniter is fried in some way...that will keep the trailing side from firing too? Still having problems getting my trailing side to fire as well.