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Shazbot! More Ignition woes again!

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Bret

Bret

Yoda
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Ok like I said in the other tread - I knew there was another shoe waiting to drop.

Well I got everything back together and am still awaiting some parts before I start the installation of the alloy head and new camshaft. But in the mean time I wanted to make sure everything else was fine first.

Anyway as some of you know I installed my new Mallory Dizzy with the PerTronix Electronic Ignition upgrade. Well when I run the RPMs above 3-4k it stumbles and falls flat on its face and starts to miss & back fire.

I'm thinking I have a tired old coil that is giving going south on me (field collapsing or can’t respond fast enough to the demand). Now it measures ok and might not be the real problem, but given that it’s about 7 years old, I’ve gone ahead & ordered a replacement just to be safe.

Another possibility is that the weights on the Mallory could be advancing more than 30-32 degrees at 3-4,000 RPMs but I’m not sure that it’s a dizzy the problem as it was doing the same thing with my old sloppy coil too.

Yet another possibility that my mechanic pointed out to me last week is that my Catalytic could be partially clogged and is restricting the exhaust and according to him would tend to bog the system down. If this is the case I won’t be able to do anything about it until I get my bits & parts back from the local welding shop here in town.

Oh well – one step forward, two steps back. Such is the case when navigating uncharted territory I guess.

Any thoughts are welcome and I’ll have some more updates probably this weekend.
 
check the Dizzy out carefully, a friend of mine had one go bad recently with less than a thousand miles on it. The jury is still out on wether Mallory is gonna make it good or not.
 
exhaust restriction is easily diagnosed. Hook up a vacuum gauge. Hold the rpm up to an engine speed you suspect of causing problems. i.e. 3500. Hold it there. If restricted the vacuum gauge will show you.
 
ccougill said:
check the Dizzy out carefully, a friend of mine had one go bad recently with less than a thousand miles on it. The jury is still out on wether Mallory is gonna make it good or not.
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Again it's doing the same thing it was before the Dizzy was installed. While I haven't ruled out anything - I'm not so sure the Mallory is related in any way to this problem.
 
bret typed" Another possibility is that the weights on the Mallory could be advancing more than 30-32 degrees at 3-4,000 RPMs "

More realistic based on your symptons would be your not getting any advance. If you were getting to much , you most likely at worst would get some pinging.
 
Update! I've yet to try the new coil I ordered, but on a hunch I contacted our good friends in Moss Motors' Technical Support department to see if they’ve had any problems with their EFI kit related to the Ignition system.

Well after talking to a couple different folks – they admitted that there’ve been some customers reporting issues with the “sensitivity” of the coil tachometer pick-up to the ECU. In fact the symptoms they described where identical to what I'm seeing (bogging down at higher RPMS) and it there case it's because the ECU can't see the RPMs via the coil Tachometer pickup. I’ve been promised and assured that they have the ability to increase the sensitivity and that one of their primary tech support specialists will be contacting me this morning.

Honestly I think they where a bit surprised at what I’d already done troubleshooting-wise thus far, because I half expected them to give me a couple “other things to try or look at before they’d admit that there was anything going on with the EFI kit. That said I was impressed that they where so willing to work with me even if it turns out not to be an EFI problem.

I’ll post another update when I have more to report.
 
That's starting to sound a bit like Micro$haft!! You're a BETA TESTER!!!
 
DrEntropy said:
That's starting to sound a bit like Micro$haft!! You're a BETA TESTER!!!
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Yeah well I didn't really sign up for that and I though they had pleanty of these out there already. I even told them I have an O-scope if they need me to check signals to & from the ECU but I'd need the schematic to do that or have someone walk me through it.

But what the heck if they truely want my help I don't mind at all. But they've got to supply me with the schematic and the ability to access the ECU in trade. But I doubt that's going to happen. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
OK, I talked had a great chat with the Moss tech guy this morning. He gave me a couple things to check out over the weekend and I'll get back with him on Monday with the results.

First thing he seems to thing is a fuel starvation issue. I got a fuel pressure gauge I'm going to hook up to confirm or deny that in a little bit. Likewise he wants me to hook up my dwell meter at the same time to see what one fails first.

At face value the good money according to the tech, seems to be on fuel starvation causing all the problem and not the ignition. But the test should tell us pretty quickly one way or another.

Got'a confess I was most impressed at the end of our conversation. The tech gave me his direct extension and told me to call back on Monday. Then said “I will be working with you until this is resolved”.
 
if it's fuel starvation, would it be possible that the ECU isn't "properly" mapped for the needs of your engine?

Didn't you say not too long ago that the engine had been bored out previously? Wouldn't that have an effect on how much air it pulls in at high RPMs?

Unless I'm mistaken, the Moss EFI kit doesn't use a "Mass Air Flow" sensor. So, if the fuel press, and dwell check out fine, then I'm thinking it might be possible the ECU just isn't delivering the fuel the engine wants.
 
My engine has had some work done to it in the past but we're not really sure what exactly. We do know it's got flat pistons and that the head was decked at one time or another. So the actual compression ratio is unknown.

But we won't know for sure if it's been bored out or not until I get the head off when I get ready to install the alloy head. But there've been some delays at the shop so who knows for sure when that'll be.

In the meantime I performed the procedure as the Moss tech support guy suggested. The good news is I did find my fuel pressure was about 10 psi. Wasn't sure if that was good or bad so I pulled the fuel filter and it jumped to about 15 psi. Not sure if that’s the problem or not. But I guess all the work I've done lately I might've had some crud & contaminants break free inside the fuel tank that could have clogged the filter.

But it looks like I'm running on fumes right now so I have to run out and get some more fuel. While I’m out I’m going to pick up a new fuel filter and some fuel treatment too.
 
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