Loony ignition wont fire

[blazeron32s]

hey guys
i got a little problem here. my husband and i bought an 85 s-10 blazer for $600 about 7 months ago, and it ran fine for awhile. THENNNNNNN.. .. the truck would not fire after it was hot. It would fire just fine cold, then one day, it said "screw you" and just wouldn't fire. Since then, we have replaced the ignition module and the pickup coil. STILL no spark at the coil. then we tried a coil off of an 89 firebird with the 2.8 and still no spark at the coil. Has anybody had this problem with their 2.8 in a 4wd blazer? if so, what was wrong? The wires under the dash are rigged really weird. we are going to purchase another multi-meter here real soon, we blew our old one. if there is a way we can check by running wires and trying to bypass fuseable links, we have plenty of wire. all help that can be offered would be greatly appreciated. this is a daily driver, so we dont have to drive our mustang.

[dracer398]

Have You checked for power at the coil? I'd start there and work back to the Ignition switch on the column. The cheap Hanes manuals have halfway decent wiring diagrams that might help too.

Good Luck!

[blazeron32s]

Okay, we rotated the engine with the cap off. the rotor spins. we have power according to the test light, in all 4 wires. but we still have no spark at the coil. does this help any in diagnosing this problem?

[blazeron32s]

hey guys
I have been doing some more research on my ignition problem, and someone sent me an article that I am going to quote, "Don't start checking things hit or miss, Go get the wiring diagram so you know what you're dealing with. I remember one case where we wasted a lot of time on a mid-'80s GM pickup. If we'd checked the wiring diagram, we'd have known there was a separate spark control module present, which turned out to be the problem." Now, acording to Haynes, the only sensors I have are, EGR Vacuum rregulator valve solenoid, Injector #2, Injector #1, Oxygen sensor, Idle air control valve, fuel pump & sensor, oil pressure switch, Fuel pump prime, fuel pump relay, ECS module, ECS knock sensor, power train control module, manifold absolute pressure sensor, throttle position sensor, & engine coolant temperature sensor. We were looking for the computer data link (it says i have one, but doesnt say where), and cannot find it. from our past experience, GMs are under the steering column. Does this truck have one? And where would it be if so? Sorry so long of a post, but i figure maybe this may lead somewhere. I am thinking that it is definately my coil, but I want a little feedback before I go buy it. Are all 4 wires going into the coil supposed to have power? OR is one of them supposed to be a ground? If one is supposed to be a ground, but has power, could that point more directly toward the coil? (all 4 of my wires coming out of the coil have power.) Words anyone?

[dracer398]

Did ya get that thing running yet? You said it's an 85 and it has fuel injection?

[blazeron32s]

hey, i havent gotten back to you because its not fixed yet. I think its just the coil by all indication and by all methods of troubleshooting. as far as fuel injection, this is what i know. I have a single injector sitting on top of my primary side of the carburetor and another injector looking (cant see it very well) on the secondary side. I thought it was a TBI but I guess I could be wrong. I have 2 electrical connectors coming in. One right where the float bowl is, and the other on the front side. I am told that its probably a Rochester E2SE carburetor and that i have a distributor and ignition system the same as a TBI system. However it does not have the ECS bypass wire under the dash and timing is set by removing the 4 wire connector from the distributor. I HATE THIS ENGINE! i have a 350 sittin' on an engine stand in my back yard that we are rebuilding to put in that, along with all the solid axles and all that stuff, but thats another story, for now i just need this running. i think i am going to just get a coil and put it in, and see if that doesnt fix it. i am just so tired of pouring money into an engine i am not going to use. Thanks again 4 the help, i WILL keep you posted to any changes.

[dracer398]

This might help with the 350 transplant. I myself have done one and the book offered by www.jagsthatrun.com is well worth the money. They even have full size motor mount prints!

[blazeron32s]

hey -
okay, here goes. here is the lowdown... we;ve gone through and changed the coil, pickup coil, ignition module, and guess what again?? THE COIL!!!! i thought it might be a bad one, so i took it back and replaced it again, and IT STILL WONT FIRE. NO SPARK, NO FIRE. NO GO. HEEEEEEEEEEEEELLLLLLLLLLLLLLPPPPPPPPPPPPPP
the 4 wires coming into the coil, all have 12.3 volts. The battery has 12.3 volts in it. when the engine is cranked, the voltage drops down to about 9.5 - 10. The side of the ignition module, that has the three prong connector has voltage coming in that is 12 volts. the pickup coil is reading that voltage is getting there. the only 2 things that we can think of, that are the problem, is the entire wiring harness inside and out or the starter solenoid s-terminal. what would be the chances that the s-terminal on the starter solenoid would be bad? or that the starter solenoid itself would be bad? where does the wire that comes from the starter solenoid go to ? so we can test that wire to make sure that it is sending a signal to the ignition. we have a wiring harness that we can buy from a salvage yard for $75 inside and out garunteed to be good. is it worth it? could there be any chance that the harness itself is bad? i know we have a few wires that arent connected anywhere but it ran with them unnconnected before. Any input guys... i need it.

[papereater]

It's been a few months since your last post, have you gotten that problem fixed yet?

[blazeron32s]

no wish i could say we have. weve walked away from it temporarily to get our other primary vehicles in good running order, instead of continually pouring money into the s-10, and getting nowhere. my husband and i have also been going back and forth being sick at different times, & my husband is in the navy, and they have been beyond busy since august. i seriously think its in the wires, god only knows where, and i have considered replacing the wiring in it to know that its done right and all the mickey-moused crap would be outta there. thanks for checking up, but thats all for now.

[papereater]

OK. Here goes 5 bucks. I had a similar problem on my '84. There are 2 Fusible links on mine. Originally they look like black M-80's and the wires that attach to them look like no other wires in the harness. As I recall, they were braided.
I finally had to replace the links. If I had to go back in there again I'd say they're located in that mess just above the starter.

[BlazHer]

Did you ever fix your problem? I have 85 4wd blazer same problem.

[blazeron32s]

Hey. No I have no fixed it, in fact I gave up on fixing it after an automotive electrician thats been in the game for 40 years couldn't figure it out. I will be moving onto the 350 swap. The fusible links that papereater mentioned - i cannot find them anywhere. they're not above the starter, and i cannot find them anywhere else. Ive given up on the daily driver concept with it and am putting a 454 in my camaro as we speak. When $$ allows we'll do the swap mentioned in my signature. If you are having the same problems, the beset i can reccomend is trying everything that is mentioned in this particular forum. I have tried/done everything mentioned, and nothing has worked. You may have better luck, hopefully your problem is not as in depth as mine. I would reccomend starting with replacing the ignition modulator, pickup coil, and coil, off the bad those are the primary suspects. If its not that...start checking wires and make sure power is going TO the coil with the proper ammount of voltage (if you have a 12.4v battery, you should have ~12 volts to the coil.) You can pick up a Haynes book and it tells you exactly how much voltage needs to go to each component. Im going to assume your starter wires have a good connection (you have checked them, right?), and that the ground to your battery and both battery cables are in good -clean- no acid buildup or corrosion. I know it sounds basic, but it can make the difference in some cases. The only other thing i have, is to replace the whole damn ignition setup to an MSD. Best of luck, keep us posted.

[NovaRod]

We have similar symptoms on a 2.2L '96. Take a look aqt the post below.

If you or anyone has any insight, please post. We will do the same. Thanks!
NovaRod

http://www.automotiveforums.com/vbul...d.php?t=188705

[recurve]

This is a sad story blazeron. I can tell from your posts that you know much more about vehicles than I do but can I suggest one thing?

Is fuel getting to the engine? Do you have adequate fuel pressure? Do you hear the fuel pump when you turn your ignition key halfway?

It is a well known problem with Blazers (especially in the '97 model year) to have a condition where the starter will turn the engine over but it will not ignite. Further symptoms is that the dash lights don't come on and the fuel pump can not be heard when the ignition key is turned halfway.

The fix is to replace the ignition switch. It can start as an intermittant problem (sometimes works) but can become a permanent problem.

Take care,
-- recurve