Has anyone had problems running a MSD ignition with the Howell Fuel injection? Problem: Motor starts and runs at speed well, when you try to idle, it loads up. Went though all the checks fuel pressure, vac lines, line voltage, has the MSD filter for the computer. Some other has had problems trying to run the system with after market ingnition. Like to here some hints before I go yanking the MSD or buying a Code Scanner

You'll likely need a tach signal cleaner. It's right in the book that MSD ignitions don't put out a clean (there words) enough signal for the GM ECM.

Tim.

I've had alot of problems w/ my Howell Inj. :mad: I live close to them and have gone over and had them fawk w/it. I'm running the MSD Off-Road box w/Pro-Billet Dist., and other MSD stuff. They also mentioned that it could be a bad Tac-filter because their computer runs of the Tac. singel. I've also been told that I might have to switch to a Vac-Advanced Dist. I've had problems w/it loading at idel and thin and cruse. I also had a ba idel air motor, messed up wiring harness, and a bad fuel pump. I'm also wondering if my Inj. is straingeling power from my engine. I have a GM crate engine H.O. 350 w/ 330hp and 380ft/lbs w/stock carb, intake, heads, ect. Well I have alot of other performance parts on it and it doesn't have any balls on the street! It's slow and I can barely get my rear tires to even squak. I have a Th350 (race built) and 4.56's 35x36 Boggers and MRT 15x10 beadlocks. ????:confused:

oh yeah give them a call and talk to Troy. He's thier computer guy and he's the only one thier that has an understanding of what your looking for. :flipoff2:

Originally posted by Duche79
oh yeah give them a call and talk to Troy. He's thier computer guy and he's the only one thier that has an understanding of what your looking for. :flipoff2:

He's right Troy is the only one to talk to. I have a BBC running a edelbrock multiport with a DUI distributor. It RIPs!!!! It was a dog with the stock throttle body. Troy did the chip

Thanks for the input Duche79, I have talked to Troy a few times, very helpful person. I do have a tach filter. Had a friend with the same problem, his never worked right until he put the stock ignition back. Going to scan for codes, if everything checks, I will put stock Ingnition back and give it a try.

I fought this forever. Troy sent me two different filters to replace the one that was in the harness and that didn't work. Then one day I was reading the MSD manual and it said when installing MSD on a GM 'remove' the tach filter. MSD on a GM requires NO filter! I tried bypassing the filter and it worked great! I was on a DIY-EFI mailing list for people having problems with Howell and I helped out a lot of people with this. If you need to know exactly what i did let me know and I'll dig up the instructions I made up to send to people. Troy is great to deal with, but he never could accept that this was the fix :rolleyes:

Are you talking about the filter that comes with the MSD for tack and fuel injection or the filter that Howell sends you to put in their harness? I have them all! Please tell me what you did. Did yours do the same thing mine is doing, load up at idle?

Thanks:)

There is a little filter in the harness from the GM ECM for the Tach wire. Troy gave me a new one and it hasn't done anything. He also had me disconect my Monster Tach because he said it might be distorting the single or something. That didn't work. I'm going to try and by pass the filter this weekend. did you just short out over the filter or what?

For the past 2 nights I have passed out in the shop, breathing raw gas fumes. Tonight, first going to eat a rather large prime rib then going to put the stock HEI ingition back in and see how it works then. I don't see how any filter can correct a signal when the MSD-6 sends fire for 20 degrees of the rotation of the crank. No wonder the ECM can't read it. I will keep you posted. At least I will no if it is my ingnition that is causing the problem, then I can go from there.

I am talking about the filter in the Howell harness. It is about 6" or so from the computer taped up in the harness with 4 wires going to it. Power, ground, tach signal in from the distributor or MSD, and tach signal to the computer. What you want to do is remove it and splice the wire from the MSD directly to the wire going to the computer. If i remember right the wire from the ignition is white and the one into the computer is orange.(I've hunted all over and cant find the instructions i wrote up)

Mine was running exactly like yours. I put a scanner on it and found that the tach signal going to the computer was being multiplied by the filter. When it was idling it was getting a signal that the engine was running at about 2000 rpm and it responded by making it very rich. At higher rpm's the multplication was less making it run better than it did at idle. I hope this makes sense. I'll keep digging for my notes on it. If this isn't clear let me know and I'll try to give you more detail.

This weekend I took the MSD off and installed factory
ingnition. All works fine now. Howell sent me a special filter
to wire in the harness for the MSD, I suppose it was probally a fancy way of doing what crawler did, mine still would run right.
Was tired of throwing Ben Franks at it so I put the factory ingnition back, and it works great now.

:)