Any auto Mechanics out there?

jacobs · #1 01/21/05, 02:05 PM

I have an 87 Range Rover that is going through ignition modules like crazy and they are not cheap. I also burned up 2 ignition coils. I can't seem to locate the problem. The Range Rovers had a problem with ignition modules getting too hot and burning out because they were right next to where the radiator hose connected to the engine and it was on the back side of the distributor. They made a relocation kit to remedy this problem and I bought one of them. This seemed to do the trick and I was just beginning to trust the vehicle when it burned out another module. The only thing I haven't tried yet is running another ground from the block to the frame and putting a 12 volt resister before the ignition coil.

Has anyone run into a problem like this before? What causes and ignition module to burn up after 500 miles? The modules have a 1 year warranty from the place I order them from and they deal strictly in Rovers. He said I've gone through more modules than all the other customers combined last year!

Cosmic · #2 01/21/05, 02:50 PM

In its new location, does the module feel warm or hot to the touch after being in operation for a few minutes.

Would approach the problem in a couple of different ways.

1. Control the ambient temperature in the area of the module. Could be add more heat sinking to its mounting area or even install a small aux fan and blow cold outside air on it continuous. How you duct the air is important, maybe don't need the fan, if you can scoop duct some air via a rig designed to get it thru normal car motion. Remove the module from seeing ambient under hood (bonnet

) temperature by some means. Datsuns and many Japanese cars locate the module in the passenger compartment is that possible here. Some even put it under the back seat. Most it is in the passenger footwell.

2. Could be just a screwed up design. Is this common in Rovers with the module relocated? What is a typical life time? Dodge Omni's had a similar problem in their distributors and it was flawed design, aluminum in the cap / connections. Just had to know to clean the puppy every few thousand miles. Went thru a lot of caps compared to cars using copper / brass.

3. If the problem is electronic in nature, can be bad. Think along the line of what can isolate it. Same deal in the old Omni's, some compacts, they used a limiter resistor. It was a common source of ignition failures. Always kept a spare in the glove box. Yup, maybe trying to get a better ground will help.

Would try to cool it better in some manner, mounting on a big copper heat sink plate and blowing cold air on the combo might be a good fix if the real underlying cause is heat related. Also look at how much it vibrates in its present location. Heat and vibration are the big killers of electronics. Moving the module into the passenger compartment might be the best if possible.

UncleTom · #3 01/21/05, 03:43 PM

Is there supose to be a type of heat transfer grease used on the module to mounting sink. On fords and gms it is used to transfer the heat or they wont last long. It is put on the module and then bolted to the sink. Then the grease squishes out. Just my .02.

agmantoo · #4 01/21/05, 03:50 PM

Often people get the wires to the two small connectors on the coil reversed. The coil will run the vehicle wired either way but the coil will heat when the primary and the secondary are not observed.

jacobs · #5 01/21/05, 10:16 PM

Quote:

Originally Posted by agmantoo

Often people get the wires to the two small connectors on the coil reversed. The coil will run the vehicle wired either way but the coil will heat when the primary and the secondary are not observed.

I might have to check this out. I replaced the coils the same way they were hooked up before, thinking that they would be right on the old coil. The connections on the coil have male and female spade connectors, male on one side and female on the other, but if a previous owner replace it wrong....?!!

As far as heat, the relocation kit puts the ign. module by the coil on the fender, away from any heat source. That shouldn't be a problem, especially since it has been in the single digits here for the last week.

jacobs · #6 01/21/05, 10:24 PM

Quote:

Originally Posted by UncleTom

Is there supose to be a type of heat transfer grease used on the module to mounting sink. On fords and gms it is used to transfer the heat or they wont last long. It is put on the module and then bolted to the sink. Then the grease squishes out. Just my .02.

The last module I gooped the grease on extra thick, but I just had a generic electrolytic grease (I'm an electrician, go figure!) and not the "automotive" grease. Shouldn't make a difference, but it's a possibility. I'm at the point of trying just about everything. I think that when I replace this module I will dump it on some unsuspecting individual, like it was dumped on me, but I just can't do that. I'm the type of person that has a conscience and would give the person their money back. That's kind of rare these days, but that's the way I was brought up!

HermitJohn · #7 01/22/05, 02:02 AM

If its a heat problem and sounds like it is if the company made a relocation kit, go look at various methods computer people use to cool processors especially when overclocking. Bigger heat sink, special extra-efficient heat transferring greases, special fans, etc. Some even water cooled their processors or used the cooling thermosistor out of those little 12V refrigerators you plug into your cigarette lighter in your car.

Also is this vehicle computerized? The older non-computerized electronic ignition modules were fairly simple to interchange. For example Volvo used a very expensive Bosch module and Nissan used their own very expensive module. I have replaced both with a pre-computer GM module which is about $12 at AutoZone. Made my own heatsink out of chunk aluminum cut from bottom of junked skillet. Just used generic dielectric grease from NAPA that I keep around to use on other things. I also used the GM coil like used on four and straight six engines in late 70's which is high output and external from distributor. I still wonder about Volvo and Nissan (and I am sure others also) wanting hundreds of dollars for basically same under $20 modules used by GM, Ford, and Chrysler. Pre-computer era modules are basically just a big heavy duty transistor. The computer era modules are also just a big transistor with some electronics added so computer can control timing advance via the module. By way I like the GM modules since I control the size of heat sink. The old Chryslers for example had heat sink as part of the module and I think it was too small. I used to have an old '76 Dodge pickup that melted a module every once in a while. Learned to always carry a spare. I suspect the GM module and coil would have worked on it, but that was before I had experimented using it on Volvo and Nissan systems so didnt know how interchangable these modules are. Right now I am using a GM module and coil in my Ford truck, just because I changed to an I-6 with 70s era electronic distributor from a point ignition V8 and didnt have a Ford module setting around. As I said I just didnt have a Ford module around , but had extra GM module so used that. I think the Ford modules were ok, although remember something about Ford coils giving problems on that era system.

Cindy in KY · #8 01/22/05, 06:59 AM

Don't know if this will help at all, but it sure won't hurt. I went thru allot of modules on my other pickup, before I sold it. They would get hot, and after they cooled off, the truck would start again. I would keep all the used ones in the truck, and swap them out, till one started the truck. Seemed the hotter I ran the truck, the more it would happen. (if I was in a hurry) All the modules were either made in Mexico or overseas. I got a bit tired of this, and went to Parts America, and got one made in the US. Never once had a problem with that one. The modules I was buying that kept going out were about 23 bucks apiece, don't remember what the Parts Amercia one cost, probably about the same.

I know it's frustrating, I spent many an afternoon, sitting on a country road, dead in the water. And I had a bright yellow primered truck, and many a farmer on a tractor would drive out of his field, to come check on me. I'd tell them I'd be there about a hour, reading the paper, waiting for Buttercup to cool off, and no, I'm not out of gas, but thanks so much anyway. Found our best source for round bales of alfalfa this way, been buying from him ever since.

heelpin · #9 01/22/05, 12:45 PM

In most 12 volt systems, a resistor is connected in series with the primary circuit of the ignition coil. During the cranking period, the resistor is cut out of the circuit so that full voltage is applied to the coil. This insures a strong spark during cranking, and quicker starting is provided. The starting circuit is designed so that as long as the starter motor is in use, full battery voltage is applied to the coil. When the starter is not cranking, the resistance wire is cut into the circuit to reduce the voltage applied to the coil. If the engine starts when the ignition switch is turned on, but stops when the switch is released to the run position, it can indicate that a resistor is bad and should be replaced.
At no time should the resistor be bypassed out of the circuit, as that would supply constant battery voltage and burn out the coil.

patSAMMY · #10 02/06/05, 03:22 PM

Quote:

Originally Posted by heelpin

In most 12 volt systems, a resistor is connected in series with the primary circuit of the ignition coil. During the cranking period, the resistor is cut out of the circuit so that full voltage is applied to the coil. This insures a strong spark during cranking, and quicker starting is provided. The starting circuit is designed so that as long as the starter motor is in use, full battery voltage is applied to the coil. When the starter is not cranking, the resistance wire is cut into the circuit to reduce the voltage applied to the coil. If the engine starts when the ignition switch is turned on, but stops when the switch is released to the run position, it can indicate that a resistor is bad and should be replaced.
At no time should the resistor be bypassed out of the circuit, as that would supply constant battery voltage and burn out the coil.

I get no spark from plugs tryed coil new resister and new distrubiter still no spark any idea Thanx

patSAMMY · #11 05/27/07, 08:35 PM

Have this carb. 350 rebuilt motor. New everything. Problem 3#s of oil preasure when motor warms up. 50#s when it is cold. Plastigaged the bearings .003 new cam bearings new oil pump. can someone tell me way so low of pressure?

Junkmanme · #12 05/27/07, 08:45 PM

Is the oil pump powered by the camshaft? If so, you may have a worn camshaft.

fordy · #13 05/27/07, 09:03 PM

Quote:

Originally Posted by patSAMMY

Have this carb. 350 rebuilt motor. New everything. Problem 3#s of oil preasure when motor warms up. 50#s when it is cold. Plastigaged the bearings .003 new cam bearings new oil pump. can someone tell me way so low of pressure?

..................I'd be having a "come too jesus" meeting with the mechanic who did the rebuild , and let Him find the problem . , fordy...

MELOC · #14 05/27/07, 10:16 PM

bad resistor wire...maybe? does it use resistor wire?

zukgod · #15 05/28/07, 02:08 AM

Low oil pressure when it warms up could be many things. I would also have a talk with the person who built the engine. Something was not rebuilt, Oil pump,old rings,pluged pickup tube,pluged oil return lines, incorect oil. The list is huge good luck.

farminghandyman · #16 05/28/07, 09:59 AM

My son and my son in law has some old jeeps, and they had the same problems,

one day my son was towing a trailer, and the truck was over heating ever 5 miles or so, I got the idea to take the hood off the truck, we pulled the trailer the rest of the way home no heat problem, we then proceeded to punch two (electrical punch) two 3" holes in the rear out side of the hood, no more burnt up modules, and no more over heating problem, son in law did the same, no more problems, I had a 1980's gm car that was similar and punched two holes in the rear of the hood to let it ventilate and to let the heat soak out (the heating of the engine compartment after the car is shut off), and had much less problems, ran a lot cooler.

some of the modern cars are jsut to tight and do not allow for enough air flow around components,