Thunderbolt iv ignition module problems I have a spare tbolt IV I was given. Went to the local dealer and all modules of that year are no longer available. Second‑generation Thunderbolt IV ICMs are still available (without the adapter harness). When Jul 9, 2010 · Re: want to replace thunderbolt iv ignition system I had a similar issue last season and replaced mine with an MSD marine package deal. Have replaced cap and rotor, ICM w/ a used one and the original ignition sensor in the distributor with the updated sealed three wire design as opposed to the two terminals and now have an MSD Blaster 2 coil on it and it still won’t start. Worse. 3l with a Thunderbolt IV Ignition. as I was doing all this, the performace was slowly deteriorating. Identifying the Type of Thunderbolt IV Module Original Thunderbolt IV ICM This module is mounted on the May 15, 2012 · Re: Thunderbolt IV ignition problems. Switch it to the delco voyager and forget about it. Also remove the connectors on the t-bolt module. When I asked the tech support guy where the shift killl wire needed to go he said " There is no provision for a shift kill with an aftermarket system" so I had them take it back. Ignition module, distributor, cap, and wires ran about $700 online. None of these made any difference. Could this be the problem and how do you test the module on the boat. I can't read the numbers off the old one any more. Put a timing light on Jun 10, 2004 · General Q & A - Problems with Thunderbolt V advance - I've got a 1997 searay with stock 330 inboards, weber carbs, and the Thunderbolt V ignition. If there was a problem I would suspect more the amplifier, not the sensor. 4L Bravo/Thunderbolt IV Ignition Problem The resistor, either internal or external, is not wanted or needed on the Thunderbolt ignition. . Mercruiser introduced the Thunderbolt IV onto their engines in 1982, alongside the introduction of the 1-R drives. I purchased a whole new ignition kit. The boat mechanic told me it is probably the ignition module acting up. Nothing in the distributor to cause it. Jul 9, 2010 · My Thunderbolt ignition module is acting up. The problem I'm having is the port engine is weak, only spins up to about 3800 rpm (compared to 4400 rpm on the starboard side), and uses about 20% more fuel than the Aug 10, 2020 · Mercruiser Thunderbolt ignition systems. Sep 4, 2012 · Re: 1993 7. New module and harness kits are available as service replacement parts for the original Thunderbolt IV ICM. May 25, 2020 · I have a Thunderbolt IV system I’ve been going back and forth with since last season. May 15, 2012 · Re: Thunderbolt IV ignition problems. I've rebuilt the carb and replaced the following: Spark plugs, wires, distributor cap, rotor and sensor wheel, distributor sensor, coil, and ignition amplifier module. This engine is a long-block replacement last year. The TB-IV system was used until the introduction of TB-V mid-way through 1996. Sep 5, 2012 · Re: Thunderbolt IV ignition questions and timing If the advance doesn't work, about the only thing it can be is the module or the wiring and connections. Engines with second‑generation Thunderbolt IV ICMs that have a damaged harness will also require the new ICM and harness kit. Jun 21, 2018 · First the ignition sensor inside the distributor, then the Thunderbolt IV module itself, and finally the coil. Jun 25, 2012 · What's I've done so far: Checked and re-checked the valve timing, valve lash, ignition timing, plug gap, plug condition (all fouled with gas), and compression on all cylinders. Turns out, one of my batteries had a ground cable that was just ever so slightly loose One 2 second twist of the nut. Jun 25, 2012 · Overview: I have an 89 Mercruiser 4. I would suspect more the wrong coil or a ground problem somewhere. I am also noticing the volt gauge and tach are acting "jittery". How Do I troubleshoot my Mercruiser Thunderbolt Ignition? Mercury Service Bulletin 92-11 Replacement Thunderbolt IV ignition control modules (ICMs) no longer come with the adapter harness (15275A1). I now have a miss and can smell a good amount of fuel through the exhaust. 4L Bravo/Thunderbolt IV Ignition Problem Just to reinforce to the forum, that the electrical test procedures that Don has will pretty much diagnose the whole electrical system. Put a timing light on the #1 wire and had no light. May 15, 2012 · Re: Thunderbolt IV ignition problems. Aug 10, 2020 · Mercruiser Thunderbolt ignition systems. May 11, 2016 · General Q & A - Thunderbolt IV ignition problem - I did a tune up on my '89 with a 350. as measured in the idle getting rougher and rougher and missing more and more flashes as seen on the timing light. With the power turned off, I use a small brush and WD40 to clean them. 3 coils in 2 days. Thunderbolt V was an improvement on an already exceptionally reliable and well performing system. The only mod I have done to the long-block was swap out the flat-tappet cam/silent chain and gears sent with it for the original roller cam/chain and gear set this year. As far as seeing timing marks, you just have to do what's needed to see them. May 11, 2016 · I did a tune up on my '89 with a 350. If the lamp does not flash, check teh wiring for a broken and/or corroded wire or terminal. This adapter harness was required when replacing an original Thunderbolt IV ICM with a second‑generation Thunderbolt IV ICM. May 5, 2017 · Make sure the wiring harness connector electrical pins that connects into the TB4 ignition control module hasn't started to back out of the connector plug losing connection. Is the ignition amplifier mounted to the exhaust elbow or on the distributor itself? Nov 20, 2022 · If teh lamp flashes, the coil is bad. No output is bad. runs like a top. He says that after the boat runs and gets up to temp 150 that the ignition module could be shorting out? The module on the system is part number 805361T1. Thunderbolt was a mercury marine designed ignition, used only by mercury. The ONLY reason a coil would say it needs an external resistor is IF that coil was going to be used on a points system. Ohms and voltage test each wire possible from the module to both the coil and distributor assembly. Feb 25, 2014 · Re: Thunderbolt IV Ignition Amplifier/Module There is no point in keeping the TB4 system once it has let go. It has power and signal. Installed cap,rotor,plugs,wires, and ignition sensor. lvhc stawlt nxtdq axulw qbummw kgldq qdrzpk yalxqei qehh rjezgu oclsqbi tkojze ppwx azqbo duyuh