Topic: Checking for spark

[83MT]

My truck has a rebuilt engine with about 1,000 miles on it. It's always fired right up, although every now and then it kind of "chugs" a bit when it starts, then chugs faster and faster until it's running smoothly. Saturday I drove it in the morning, it sat for a few hours, then I went to drive it again, it started right up, ran for about 5 seconds and died. Won't start again. Wouldn't start yesterday, won't start this morning. I can smell gas if I crank it long enough, so I'm assuming it's getting gas. How do I check for spark? Pull a plug, connect it back to the wire and see if there's spark when someone cranks it? Or is there another way?

Also what else should I be looking for?

Sorry- it's an '83, 22R.

[x2nou]

Clean your egr . I have that similar issue my egr was clog

[83MT [OP]]

That would keep it from starting?

[gnob]

pull the coil wire off the dist cap end.
put the terminal near a ground and crank the motor to check for spark.

the EGR could potentially cause a no start if it was stuck open.

if you still dont have spark, check the coil negative with a test light to see if there is flash.  if not, the pick up in the dist is prob bad.

[79coyotefrg]

lick a finger on each hand,  hold the coil wire with one hand with wet finger on metal end,   put other finger on engine, have someone crank the engine over several times



 

[83MT [OP]]

Ok thanks! Tried the wet finger thing, feeling much better this morning...

No, I pulled a plug and think maybe by holding it against the valve cover I was grounding it? Didn't see spark. I'll try that with the coil wire at lunch. So I pull the coil wire at the distributer end and hold the terminal close to the engine (or anything metal) and look for spark?

The distributer is only about 1000 miles and 3 months old, but I guess I should never just automatically rule it out. I definitely am getting fuel, checked that last night.

If there is no spark coming from the coil, then it's the coil that's dead? Or are there other things to check before replacing it? And just to be clear, the ignition coil is totally seperate from the starter, right? So since it's cranking the starter is obviously fine, but the coil could still be bad?

I don't know what any of these parts are called...but...there is a metal pipe coming off the intake which threads onto the egr with a nut. I cleaned that out and the intake where it attaches. What do I clean on the egr valve? You've got the part that actually attaches to the head, then the diaphram (?) that sits on top of it. What else do I clean.

[83MT [OP]]

Well, no spark coming from the coil, so I'll try replacing that and go from there.

[toolman]

ignitor may be bad..check around on ebay for a good used one.

[kneedownnate]

Check your coil wires real good before buying a new coil.  I find tons of coil wires look good, maybe even feel ok with a little tug or wiggle, then fully give out when you pull a tiny bit more.  We had a problem boat with a weak connection at a coil wire this summer, and I found it in a few seconds after sending somebody else out on it on 4 different occassions 

[79coyotefrg]

holding the spark plug or coil wire close to a ground SHOULD  show spark,  ive had my coil wire jump a spark 2 inches right to my finger

i might have a couple ignitors laying around

[83MT [OP]]

Great! I'll let you know if the coil doesn't do it (already ordered one). I'll also check all the wire connections. I don't mind replacing some of this stuff with new stuff because this is my daily driver/road trip vehicle and even though it's got a new clutch/engine/transmission all this 25 year old wiring & circuitry scares me a bit. The dealership guy (who steered me to the parts store because this crap is pricey at the dealership) said that he's heard from the mechanics that the ignitor is usually last to go on these trucks (and about 3 times the price of the coil) so trying the coil first is the way to go. We'll see. Coil should be here this morning.

[gnob]

it is more likely the dist pickup than coil.

[83MT [OP]]

Yeah, except I'm not seeing any spark coming from the coil, so my problem is probably there.

[83MT [OP]]

Not the coil...so on to the ignitor...

[Wermz84]

probably dum, but I would double check all the mechanical stuff, timing, chain what not.  just to be sure.     Good luck.

[Cheesemaker]

Are you getting any power to the ignitor?  Checked your fuses?

[83MT [OP]]

As far as I know I'm getting power to the ignitor. Without the equipment the FSM talks about for checking that stuff, I don't know what to check other than connections and the fuse. As far as I saw, there is one fuse labeled "engine". I'm assuming that's the only one I'd need to check? It was fine.

I made sure my distributer was bolted on tight and all that. The timing was set just a few weeks ago, so that shouldn't be it...

Anyway since I don't seem to be getting spark from the coil, the problem seems to be on that end of things. My new (expensive) ignitor will be here Monday, so I guess for now I just double check all wires/grounds etc and wait to see if that's it next week.

Thanks for the help.

[85yotabox]

i had the same problem, kinda...i had spark and fuel but my truck still wouldnt run.  so after a lot of troubleshooting i found that a wire connection under the dash was loose. (someone before me spliced into it and made the wire to short which caused it to pull out of the clip just enough to loose connection.) it was one of the wires commond down the steering colum form the ignituion.  sounds like that could be it but maby not. hope it helps!!

[83MT [OP]]

Ok. I did check around under there but that makes me think maybe I should spend a bit more time. Unfortunately a PO did some wiring stuff in my truck, although they more added wires, not messed with existing stuff. But because of that I've got wires that I can tell were grounds that are broken off, and wires coming in from the firewall that don't connect with anything, and it was running fine that way before. So...hard to tell if there's a new one loose. This could be a good opportunity to find out where (if anywhere) all those wires go. Thanks.

[gnob]

hey bud, the pickup in the dist sends signal to fire the coil.  the pickup is actually signalling the ignitor to go to ground.

losing an ignitor is pretty rare as far as i know.

generally you check the pick up using an ohm meter across the dist plug.
hsould be 200-2000 ohms.

also you can put a test light on the negative side of the coil and crank the motor, see if the lamp flashes.

its gonna sting when the ignitor doesnt fix the problem as there is generally no returns on electrical itmes.

[83MT [OP]]

Oh really? Well s&*t. We'll see how that goes, then. The Toyota shop I talked to only mentioned the coil & ignitor so I figured that's what I'd go with. I guess I'll look into the pickup and see how cheap it is. If it's cheap I'll just buy it now. I really need my truck to be running next week.

I don't have any of those tools to check this stuff, but honestly after spending what I've spent on parts, it sure doesn't seem like a bad investment to buy those check tools at this point...

Well if nothing else, I'll have a lot more new electrical stuff on my truck. Now I just have to worry about the actual wires...

[83MT [OP]]

Wasn't the distributer pickup. We'll find out after lunch if it's the ignitor.




Or...maybe we won't. At some point a PO installed a later model ignitor by cutting off a plug and splicing in a newer one, so the '83 ignitor won't plug in. Try again, back again tomorrow.

[83MT [OP]]

New ignitor, fired right up! Parts guy says the internals for the '83 and 85-88 ignitors are different, and even though somebody made the plugs work, I'll possibly have the same problem again down the road...oh well, I guess. Hopefully I'll get a few years out of this one, anyways. I can see why these trucks make better 2nd vehicles. With weird problems like this, it's good to not need it working again fast. If I had time, I would have found the correct plug at a junk yard and spliced it back in so I could use the correct ignitor, but I needed the truck running so I spent a lot on an ignitor that may not last too long since it wasn't built for my truck...we'll see.