1992 B2600i Ignition problem: Coil check?

[magnumtoy]

Here's my situation.

Engine will crank no problem. Checked for spark. No spark at plug or coil wire. I want to check the coil itself, but the manual's test says to check the resistance while the engine has run and warmed the coil up. (duh, can't run the engine, won't start!?!?)

How do I confirm or rule out the coil?

(Also, what is the little thing that is mounted right next to the coil, actually sharing the same bracket? It's a little 3/4"x3/4"x1/4" thick black, potted thing with a 2-wire connector connected to it. Does it have anything to do with the ignition?)

Thanks.

[Tom Brockman]

Originally Posted by magnumtoy

Here's my situation.

Engine will crank no problem. Checked for spark. No spark at plug or coil wire. I want to check the coil itself, but the manual's test says to check the resistance while the engine has run and warmed the coil up. (duh, can't run the engine, won't start!?!?)

How do I confirm or rule out the coil?

(Also, what is the little thing that is mounted right next to the coil, actually sharing the same bracket? It's a little 3/4"x3/4"x1/4" thick black, potted thing with a 2-wire connector connected to it. Does it have anything to do with the ignition?)

Thanks.

I believe that box is a capacitor in the transistor circuit. The transistor works the coil to create the spark. The transistor might be the problem if you are not getting a spark. My Chilton manual claims it can't be tested. Only replaced. Don't see why the coil should be tested when the engine is hot. Primary resistance should be 0.81-0.99 ohm, but mine measures about 1.8 ohms. Secondary resistance is 6 to 30K ohm. Mine measures about 12K ohm. Also, test the wires from the coil to the distributor and from the distributor to the spark plugs. The spec is 16K ohms per 3.28 feet. Look for cracks in these wires.

[magnumtoy]

Thanks. Does the chiltons manual say anything about the plug/coil wire resistance saying "not to exceed 16,000 ohms per meter"? You'd think it'd be the other way around... like "must exceed" or something? I'm working out of a Haynes manual. Is Chiltons any better?

I DID measure my primary coil resistance (cold) and it was 1.5 ohms.

I DO see something on the elec. schematic that shows an "external resistor" between the ignition sw. and the coil, but in the verbage and the resistor specification in my manual, it looks like only 1988 B2600 has it. Does Chiltons clarify this?

If I'm getting no spark at the coil wire or plug wires, there's really not much else that could be wrong than the coil or the resistor itself, right?

Thanks for the advice. Is yours the same model as mine? How many miles do you have on yours? Anything major gone wrong recently? Mine has been pretty good. Water pump once, pwr steering line once. Too bad it's only a 2WD. I haul firewood with it.

[Tom Brockman]

Originally Posted by magnumtoy

Thanks. Does the chiltons manual say anything about the plug/coil wire resistance saying "not to exceed 16,000 ohms per meter"? You'd think it'd be the other way around... like "must exceed" or something? I'm working out of a Haynes manual. Is Chiltons any better?

I DID measure my primary coil resistance (cold) and it was 1.5 ohms.

I DO see something on the elec. schematic that shows an "external resistor" between the ignition sw. and the coil, but in the verbage and the resistor specification in my manual, it looks like only 1988 B2600 has it. Does Chiltons clarify this?

If I'm getting no spark at the coil wire or plug wires, there's really not much else that could be wrong than the coil or the resistor itself, right?

Thanks for the advice. Is yours the same model as mine? How many miles do you have on yours? Anything major gone wrong recently? Mine has been pretty good. Water pump once, pwr steering line once. Too bad it's only a 2WD. I haul firewood with it.

It doesn't say "not to exceed 16,000 ohms per meter" just that this resistance is 16K ohm per 3.28 feet. So implied, I guessing the resistance of each wire should be less than 16K ohms because the wires are less than 3.28 feet in length.

I think the Chilton manuals are alot better than the Haynes. I've used Haynes before. Some help, but not enough.

Don't think the box is an external resistor. Mine measures greater than 20 Meg ohms. So I think it is a capacitor that is not shown in the diagrams. There is an external resistor in the documentation for some of the other model engines (not B2600i 2.6L).

I'm pretty sure the other box down beside the coil is the transistor used to work the coil to make the spark. If this is bad, then you would not get a spark. But there is no test for it. You just have to replace it.

I have a 1992 B2600i with the 2.6L engine. Bought it used about a year ago. Has 69K miles on it. Have had trouble starting it last winter and just recently. Think it might be the fuel pump, so I'm in the process of replacing this pump.

Hope this helps.

[magnumtoy]

Well, damn it all. I'm running out of ideas.

I figured out that the part right next to the coil is the in ignition module. After thinking "what else could it be that could go wrong?" I went ahead and replaced the module. STILL no spark, no start. I also see a relay-looking thing a few inches away from the coil and module that is mounted on the side panel, tucked just under the hood. It's got a rubber sleeve around it. I pulled it out and it says on it...

LA10
DC12V 10A
N.O
IMASEN
1T26

It has 4 terminals on it. Two skinny ones say "coil" and the two bigger blades say "ON" and "OFF". The connector for it runs into the same harness that the coils runs to. DO you know what this is??

I'm getting purdy damn frustrated. I might be at the end of my rope, may have to bring it in. Any more help I'd appreciate it.

I read one more thing, a fusible link near the battery, that I'll check into today after work. My manual SUCKS. That and I'm just an idiot I guess.

Thanks.

[Tom Brockman]

Originally Posted by magnumtoy

Well, damn it all. I'm running out of ideas.

I figured out that the part right next to the coil is the in ignition module. After thinking "what else could it be that could go wrong?" I went ahead and replaced the module. STILL no spark, no start. I also see a relay-looking thing a few inches away from the coil and module that is mounted on the side panel, tucked just under the hood. It's got a rubber sleeve around it. I pulled it out and it says on it...

LA10
DC12V 10A
N.O
IMASEN
1T26

It has 4 terminals on it. Two skinny ones say "coil" and the two bigger blades say "ON" and "OFF". The connector for it runs into the same harness that the coils runs to. DO you know what this is??

I'm getting purdy damn frustrated. I might be at the end of my rope, may have to bring it in. Any more help I'd appreciate it.

I read one more thing, a fusible link near the battery, that I'll check into today after work. My manual SUCKS. That and I'm just an idiot I guess.

Thanks.

I think that "relay-looking thing a few inches away from the coil and module that is mounted on the side panel" is the Circuit Opening Relay. It controls the fuel pump. You can test it by jumpering the Check Connector. This is a yellow 2-pin connector over on the opposite side panel hanging near the windshield washer fluid tank. Put your car key into the ignition switch and turn the key to ignition (so the radio plays). Then jumper the yellow connector with a small bit of wire. You should hear a clicking noise from the relay. You might need someone to help you. I found I could not both listen for the relay and giggle the wire in the connector at the same time.

I found a website you might try. http://www.justanswer.com/car-information.asp?r=gacar It costs a few bucks to get your question answered but these are people who supposedly know what they are doing.

I am fumbling around like yourself trying to figure out why my B2600i won't start. It looks to me like I have a spark, but no gas getting to the cylinders.

[magnumtoy]

I finally found this truck on alldatadiy.com (better info than my manual). For my prohlem, it looks like there is a main relay (near the battery) that controls this circuit. I'll try that tonight. Still trying to find out what relay I found near the coil, I think it is the horn relay. I'll check it tonight too.

What you call the circuit opening relay (aka fuel pump relay) is located behind the drivers side kick panel. That controls the fuel pump. You might want to check that. There's also a "fuel cut relay", located behind the LH side of instrument panel. Not sure what that does, but that's something else not in my manual, but on the alldatadiy website for my truck.

You can subscribe to the service - pay for it by the year. Good luck, let me know how your fuel search goes.

[Tom Brockman]

Yea, OK your right. That is the horn relay. It sounded to me like that was the relay I was activating when I was jumpering the 2 pin test connector for the Circuit Opening Relay. I have located the kick panel you mentioned and found the relay. Is there a relay in the position for the Fuel Cut Relay on your truck? My Chilton manual says the Fuel Cut Relay is used in the Carburetor version of the 2.2L engine, not in the 2.6L fuel injected engine.

The Main Relay in the 2.6L engines supplies power to the Airflow sensor, Self-Diagnosis checker, Fuel Injectors, ISC Solenoid Valve and the Crank Angle Sensor, but not the Ignition Coil and Igniter. The wiring diagrams show power for these is supplied through the Ignition Switch. It looks like that when the Ignition Switch is turned on, power is supplied to the Ignition Coil/Igniter and the Engine Control Unit. The Engine Control Unit then pulls in the Main Relay to supply power to the stuff mentioned above.

Maybe a little late to be asking this question. But have you checked the electrical fuses? The Engine Control Unit has fuses, Engine 15A and Room 15A. If one of these is blown then the Engine Control Unit won't work and you won't get a spark, since the Engine Control Unit controls the Ignition Coil/Igniter.

[magnumtoy]

I got it running last night! It was the main relay. Located right near the battery on the same bracket the main fuses are on. i took it off and was testing it... at first it was dead (no continuty while suppling 12v to it... then it started working as i kept testing it - adding and removing 12v multiple times. Must have been stuck open or something, even though I heard clicking. It might be getting ready to fail. Might go ahead and replace it anyway.

Re: the fuel cut relay, I'll check and post it on your other thread about your fuel problem (to keep my spark and your fuel problem separate) Thanks for your help.