Backfire above 40mph climbing needing throttle (1 Viewer)

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There is no mention of plug wires having been serviced with the rest of the tune up. That's a miss. Add to it that those aren't OE and I'm putting that way up the list...and I'm not an OE-only guy. Yazaki just makes a really good product.
 
There is no mention of plug wires having been serviced with the rest of the tune up. That's a miss. Add to it that those aren't OE and I'm putting that way up the list...and I'm not an OE-only guy. Yazaki just makes a really good product.
the plug wires were replaced with the rest but that was left off the list. I have no idea of the brand but I will go back through and ensure they're cleaned up when I get some new plugs.
Snake-oil plugs; throw them away and get OEM Denso plugs.
This is on the short list ... but I will say that after cleaning the plugs it runs a ton better today than it did prior. So I'm looking forward to adjusting the valves, new plugs and getting the carb dialed in.

I'm sure I'll get some opinions on this ... I went to set the dwell gap and hadn't paid much attention to the distributor yet ... Delco Remy 1112403 which I gather from the web was used in Chevy's back in the day. I read elsewhere that a dwell with this should be in the 28-30 range and to possibly use 10-14 BTDC vs the 7 from the book. Am I understanding this correctly or getting bad info? Would different distributors have different BTDC specs and dwell / breaker gap settings or should I target / baseline at the specs in the book regardless of the distributor? I'm also considering dropping a petronix in here, set the timing and possibly be in better shape.

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Much of this is for my record keeping at this point as I continue down the rabbit hole ... but I definitely appreciate everyone's guidance and opinions as I learn a bit more each day. Thanks!
 
Total advance is the critical timing number and how & when it gets there. Changing the static timing effects total advance. I suspect your dist could be contributing to your issue along with the plugs. Your plugs shows a rich condition, but that could be a results of your plugs, plug gap and and your dist. I would start with plugs, dwell and find what the total advance should be and set it to that number. Your dist is the unknown variable.
 
I'm sure I'll get some opinions on this ... I went to set the dwell gap and hadn't paid much attention to the distributor yet ... Delco Remy 1112403 which I gather from the web was used in Chevy's back in the day.

Sure hope that it does not still have the chevy drive gear on it, or you will be sorry! If it were mine, I would not risk it; I would ditch that dizzy and get an appropriate OEM Denso.
 
Sure hope that it does not still have the chevy drive gear on it, or you will be sorry! If it were mine, I would not risk it; I would ditch that dizzy and get an appropriate OEM Denso.
Can you expand on this? Is the Delco Remy known to have issues? It seems they were run for a long time on Chevys. Is it an overall quality or Toyota compatibility issue? Is the risk that the dizzy fails or will that failure cause other issues beyond the need to replace the dizzy if/when it fails? I read another thread where the general consensus was to replace with OEM but I also saw a few posts saying they've run it for years? I completely get wanting to go OEM but I'm also trying to work with what I have an upgrade / replace the high risk areas. Am I in one of those with this?
Thanks!
 
Can you expand on this? Is the Delco Remy known to have issues? It seems they were run for a long time on Chevys. Is it an overall quality or Toyota compatibility issue? Is the risk that the dizzy fails or will that failure cause other issues beyond the need to replace the dizzy if/when it fails? I read another thread where the general consensus was to replace with OEM but I also saw a few posts saying they've run it for years? I completely get wanting to go OEM but I'm also trying to work with what I have an upgrade / replace the high risk areas. Am I in one of those with this?
Thanks!


This:

I think it has to do with the compatibility of the gm gear meshing with the Toyota cam.

The GM dizzy helical gear can be made to mesh with the gear on the 2F camshaft, but the pattern is in fact different and it will eventually destroy itself, and the camshaft gear with it.
 
Closing the loop on this one ... I had a local land cruiser shop review the issue and asked them to also give the truck a once over (I've had it 6 weeks) to establish a baseline and let me know of any immediate concerns + items that I may want to address over the next year.

I'd already fixed the weak fuel pressure. They found an exhaust gasket leak they believe to the primary culprit. They're going to address this and make the basic carb adjustments in the next few days. They also gave me a few other mid-low priority items that I'll knock out on my own. The best part of the conversation was "this truck is in great shape for its age and should run great when we're done". Time will tell, but it was definitely the news I was looking for.

All in all, I'm glad to now have a relationship with a local shop and am looking forward to picking up the truck when I get back in town on Monday. Thanks all for the tips along the way!
 
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Closing the loop on this one ... I had a local land cruiser shop review the issue and asked them to also give the truck a once over (I've had it 6 weeks) to establish a baseline and let me know of any immediate concerns + items that I may want to address over the next year.

I'd already fixed the weak fuel pressure. They found an exhaust gasket leak they believe to the primary culprit. They're going to address this and make the basic carb adjustments in the next few days. They also gave me a few other mid-low priority items that I'll knock out on my own. The best part of the conversation was "this truck is in great shape for its age and should run great when we're done". Time will tell, but it was definitely the news I was looking for.

All in all, I'm glad to now have a relationship with a local shop and am looking forward to picking up the truck when I get back in town on Monday. Thanks all for the tips along the way!

IMHO that killer distributor would be my first priority. And if the "local land cruiser shop" you took it to, did not immediately throw it in the trash, I would question their competence. I'm being totally serious. That distributor is a ticking time bomb. It was sold by MAF back in the day, along with a Rochester carb, as a "performance" upgrade to the far superior OEM Toyota parts. That distributor has killed many a motor over the years.
 
IMHO that killer distributor would be my first priority. And if the "local land cruiser shop" you took it to, did not immediately throw it in the trash, I would question their competence. I'm being totally serious. That distributor is a ticking time bomb. It was sold by MAF back in the day, along with a Rochester carb, as a "performance" upgrade to the far superior OEM Toyota parts. That distributor has killed many a motor over the years.
Thanks - I do have an OEM distributor on its way that I'll swap in along with a set of new plugs. The local shop is Austin Land Cruiser Specialists which is the place friends and friends of friends steered me towards.
 

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