|
Post by Lost on Jul 22, 2005 13:44:50 GMT -5
Hi, I'm in desperate need of ideas on my 88 Buick Century 2.5 I just bought it and it ran great, had a little valve rattle on accel, but nothing serious, Well last night it died while driving and was hard to restart. After it started it had no power.I changed plugs and wires,no help.I pulled plug wires 1 at a time and found #1 and 4 had spark 2 and 3 didn't. I changed the coil pack that those 2 were on still no spark Any HELP!! LOL will be appreciated. Thanks Guys.
|
|
|
Post by Venturi on Jul 22, 2005 17:25:08 GMT -5
Hi Lost, If you have already replaced the coil and plug wires for cylinders 2, 3 and still have no spark, you have a bad ignition module. The coil drivers for cylinders 1 and 4 are on a separate circuit than the drivers for 2 and 3, so it’s common for one set of coil drivers to go bad without affecting the other 2 cylinders. You can test the module with a 12 volt test light and a set of long jumper wires. I use two long jumper wires each with an alligator clip at one end and a female spade terminal at the other. Remove the 2, 3 coil and connect the female spade terminal of each jumper wire to a spade terminal of the coil connector on the module. Route the jumper wires up to the topside of the engine and connect a test light between the alligator clips of the jumper wires (make sure that none of the clips or the probe of the testlight can short to ground by touching any metal parts). Crank or start the engine while observing the testlight. The testlight should flash indicating the 12 volt power source is being switched to ground and the coil driver circuit in the module is working properly. If the test light does not flash while cranking or running the engine it would indicate a bad coil driver circuit in the module. This test isn’t necessary in your case because you have already replaced everything except the ignition module. I just posted it to show how easily the module can be tested without needlessly replacing any parts.
It would also be a good idea to go ahead and replace the crank sensor when you replace the ignition module. The crank sensor is bolted to the back of the module and must be transferred to the new module anyway. These sensors are prone to failure and replacing at the same time as the module may save you from some future headaches.
Keep us posted
|
|
|
Post by ChuckB on Jul 23, 2005 15:37:48 GMT -5
Well I replaced the ignition module and now the darned engine won't start at all??? lol This is an awful predicament! I checked the wires to make sure all was connected , all hooked up but.... nothing still. Any sugestions? thanks again.
|
|
|
Post by DanD on Jul 23, 2005 20:41:56 GMT -5
From what I remember the crank sensor protrudes out the bottom of the module coil pack assembly and perhaps when you changed out the module the sensor wasn’t plugged in properly or it just didn’t like being disturbed and is now not functioning. I know this is not a very specific kind of info but if it was running before the module change then likely it something that you have over looked during reassembling or you bought a defective module. Dan.
|
|
|
Post by oldtimer5520 on Jul 23, 2005 22:42:24 GMT -5
Have you checked to make sure you are still getting spark to #1 & #4? You mentioned that you had originally replaced the coil pack for #1 & #4 cylinders, was that a new or used coil pack and is this a new or used ignition module?
|
|
|
Post by ChuckB on Jul 24, 2005 14:55:55 GMT -5
Hi guys, I sure appreciate the help and yes I replaced all but the crank sensor. All new parts. I checked for spark on 1 and 4 no fire, no fire on any of them. If crank sensor is bad, would it cause no spark? But regardless I am going to replace that today. I'll keep you updated and thanks again.
|
|
|
Post by re-tired on Jul 24, 2005 20:32:16 GMT -5
If the crank sensor came out hard,they usally do.It is VERY easy to get a crack in the tube that goes into eng. This will cause a no start. 2cents worth.
|
|
|
Post by ChuckB on Jul 24, 2005 20:43:14 GMT -5
Well, You guys are probably tired of hearing from me but...lol I changed the crank sensor also, took everything to autozone and had it tested. All tested good.I put it all back together. Guess what? no fire to any wire. AHHH I'm about to pull my hair out lol. So is there a fuse or any thing else I might check? Thanks again.
|
|
|
Post by DanD on Jul 24, 2005 20:59:05 GMT -5
When I get back to work tomorrow I’ll see if I can find a wiring diagram to post for you and maybe from there we’ll be able to tell you which wires to test for power and ground Dan.
|
|
|
Post by DanD on Jul 25, 2005 7:06:39 GMT -5
I know the image is large sorry I didn’t think it was readable when I tried to resize it. First thing is checking all the fuses in the under-dash fuse panel with a test light and the ignition switch in the run position. If they are all ok and will light the test light on both sides of the fuse. Then go to the ignition module and disconnect the two-wire connector and using a test light connected to battery negative and ignition on, test for power at the pink/black wire. Next switch the test light to battery positive and probe the black/white wire the light should light. That is the ground for the module. You could also test for power at the fuel injectors red wire with ignition on, test light connected to battery negative. The same fuse protects these two circuits, there is a splice somewhere in the loom and that is why there are two different colors, Pink/black module and red at the injector. Do not try and test the blue injector wire with a standard test light, there will be to much current flow through this kind of test light and you may burn out the computers injectors driver. Try this and let us know your findings. Dan.
|
|
|
Post by Venturi on Jul 25, 2005 9:15:20 GMT -5
Hi Lost, I’m sorry this thing’s giving you such a hard time. In addition to the checks that Dan suggests, some of these also had an extra ground wire which connected the module backing plate mounting stud (lower left corner I think). Make sure this ground wire was securely reattached to the mounting stud if so equipped.
Let us know what you find.
|
|
|
Post by ChuckB on Jul 28, 2005 12:23:13 GMT -5
Hi guys, Got busy this week and just got back on this car. I checked for power to injector, I have power there, but haven't checked for ground yet. All the fuses are getting juice to them also. I am almost betting it is some stupid little thing that I am over looking, lol, well actually over feeling ,as I can't see it at all. So I'f you can think of any thing let me know. Thanks.
|
|
|
Post by ChuckB on Jul 28, 2005 16:21:28 GMT -5
Okay I checked the 2 wire plug at ignition module. I am getting both juice and ground there, but still no spark at the wires. Checked for ground wires on bottom left stud, there are none [ it is grounded on block]. So I'm still dazed and confused with this darn thing lol.So Thanks again guys
|
|
|
Post by Venturi on Jul 29, 2005 8:55:48 GMT -5
Chuck,
Try checking for spark with the large connector at the module disconnected, this would eliminate the possibility of a shorted tach or reference circuit. With the two wire connector at the module still connected it should produce spark while cranking provided the crank sensor, module and coils are ok. If you still have no spark I’d be really suspicious of the new module, to be honest I’ve had very little luck with anything but Delco modules on these. If you still have the old module you might try reinstalling it (I know it’s a pain in the butt) to see if you still have spark on cyls 1, 4. If you then have spark on those two cylinders it would confirm that the new module is NFG.
Let us know what you find.
|
|
|
Post by ChuckB on Jul 30, 2005 13:15:58 GMT -5
Hi Venturi, I put my old ign. module back on and guess what? it starts again and only runs on 1 and 4 like it did pre new module!!! So I'm going to auto zone and see what they give next lol {hope it's a good part this time}I'll let you know how it works this time.Thanks again. P.S I'm really getting good at removal and replacement of this part LOL. ;D
|
|