I just recently bought a 1975 IH 200 4x4 pick up with a 345. It had been sitting for awhile, but I got it fired up. I suspect this thing has not ran proper in the past, because, the carb had signs of a rebuild, new fuel pump, cap , rotor, wires, and plugs, and a shiny new gold ignition box. I have had a few IH pickups in the past, but this is the first one I have had that doesn't have points ignition. I have been reading all the wonderful stories about the gold box ignition, maybe that's my problem. Here is my issue I have the truck to it will fire up and idle like a champ but as soon as you try to accelerate it starts cracking out the exhaust, like a shot gun. Plugs are new, and are firing good at low rpm near idle. I have a great running Holley 2 barrel off anther truck, good compression on all cylinders. It sure acts like week ignition. Does this sound like another gold box problem. I have an extra msd 6al box laying around , what would I all need to incorporate that into my system? It looks like everything has been replaced in the ignition short of the pickup in the distributor.
popping and banging 75 ihc 200 with gold box igniton system
- Thread starter taplin75
- Start date
Scoutboy74
Moderator
Welcome to the forum. A couple things to try before casting all suspicion squarely towards the gb amplifier module. First, verify that all spark plug wires are routed in accordance with the firing order cast into the intake manifold near the distributor and also published in the ihc service literature if you happen to own a volume. It can also be found via internet search as well. Remember that the wires are routed in a clockwise fashion around the distributor. All it takes is two wires crossed up to cause some real issues and its very easy to do. If that checks out good, next thing would be to check your timing if you have access to a timing light. Without knowing your mechanical aptitude, I'll hold off on explaining the procedure for now aside from a reminder that IH v8 engines are timed off cylinder #8 rather than #1 as with most other makes. If you need further explanation, just ask. Examine your wiring terminations at the coil and make sure they're snug. Please update us when time permits with your results from the above.
I have checked the firing order numerous times, this was the first thing I did, I was an ase certified mechanic for 14 years, and have drag raced and truck pulled for 20 years, feel free to use technical terminology, I should be able to grasp it. I also checked timing it was set at 4 to 5 degrees advance, and with vacuum unplugged it pulled 26 degrees total at about 3000 rpm. All connections appear good at the coil. I did advance the timing with out the use of the timing light till it ran somewhat better, just to see if anything changed. It was a little better but not even close to being right. It still pops and cracks out the exhaust and doesn't really have any power.
Scoutboy74
Moderator
Typically these engines wake up a little with some advance to the static timing. I wouldn't be concerned with as much as 10-12 degrees of static advance so long as there is no observed pinging/detonation during hard acceleration under a load. But, yours won't even accelerate hard at this point for whatever reason. Is the vacuum advance functioning? Can you rev to wot when the engine isn't under a load? Based on the symptoms you've described, it seems more like a fuel delivery issue or a manifold vacuum leak rather than an ignition problem. You expressed confidence in the carb condition, but I would still delve deeper into the mixer myself before crap-canning the gb. They do have a bad reputation, only somewhat deserved, but the failures are normally in units that have been in service for decades and those failures are most commonly exhibited as intermittent non-starts all the way to complete non-sparking.
Robert Kenney
Super Moderator
Re: popping and banging 75 ihc 200 with gold box ignition system
The gb system has enough components in the box to fail many ways... Is it defective it is hard to say. You seem to have enough experience to diagnose the system. A points distributer can be had for a reasonable cost or a pertronix. If you are comfortable in doing a dizzy swap/pertronix I would. Install a basic coil and see if it fixes the issue..
Have a look at the rotor contact head that swings past the wire post on the underside of the cap. Look for the witness marks left by sparking while running. They should create a erosion pattern about the middle part of the tip.. If it appears to be on the leading or trailing tip of the head, you could have a rotor phasing problem.
The gb system has enough components in the box to fail many ways... Is it defective it is hard to say. You seem to have enough experience to diagnose the system. A points distributer can be had for a reasonable cost or a pertronix. If you are comfortable in doing a dizzy swap/pertronix I would. Install a basic coil and see if it fixes the issue..
Have a look at the rotor contact head that swings past the wire post on the underside of the cap. Look for the witness marks left by sparking while running. They should create a erosion pattern about the middle part of the tip.. If it appears to be on the leading or trailing tip of the head, you could have a rotor phasing problem.