Popping under boost

Joined
Dec 22, 2015
Guys I am running 15lbs of boost on a precision 60mm turbo.
The car has been running great until last week it just died out of no where after idling for 20 minutes. I changed the plug wires and it seemed like the problem went away.

Now a few weeks later it started to pop and backfire a bit once in a while under WOT. Now every time it goes WOT I get a lot of popping.

I put on a new coil and it did nothing.any suggestions ?

I was looking in the engine bay and was wondering if it may be related to this hose missing ? See picture attached
 

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Guys I am running 15lbs of boost on a precision 60mm turbo.
The car has been running great until last week it just died out of no where after idling for 20 minutes. I changed the plug wires and it seemed like the problem went away.

Now a few weeks later it started to pop and backfire a bit once in a while under WOT. Now every time it goes WOT I get a lot of popping.

I put on a new coil and it did nothing.any suggestions ?

I was looking in the engine bay and was wondering if it may be related to this hose missing ? See picture attached
 

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I'd check the cam sensor first. It's off...Check the locator tab on the sensor and see if it sheared off.
 
Could be your ignition module. Make sure you get an ac delco. I think rock auto has best prices. If it turns out to be something else then just carry it in the trunk as a spare. You don't have a hose missing. A little sponge filter goes there.
 
I would ohm out your cool pack . I have seen brand new coil packs that where toast . Also some modules that seem okay till u get into boost . If u have acces to another known good coil pack and module I would swap and see if the problem is still there
 
If you changed the coil pack but not the module, you've only tried half the job.


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I was looking in the engine bay and was wondering if it may be related to this hose missing?

Did you try replacing the hose yet, was it always missing? I would go over ever hose and clamp, I use the KISS method.

I was running a T66 on the MR2 in my avatar and had some misfire and stumbling once under light boost (10psi) and it was due to bad gas but fortunately I had forged JE pistons so the engine just shook it off.
 
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where is the best place to buy the ignition module?

what part # plugs would you recommend for 15lbs of boost, car is a street car that runs mid 12's.?
 
where is the best place to buy the ignition module?

what part # plugs would you recommend for 15lbs of boost, car is a street car that runs mid 12's.?

I would call one of the vendors/supporters of this forum for some advice first and then price the module.

I don't think the plugs are your problem though, unless you have a fouled one, and we boost junkies need to have them gapped properly.

Use the method I learned the hard way decades ago....the KISS method. ;)
 
A few weeks ago I would get 1-2 pops under WOT, now everytime I go completely WOT I get multiple popping/misfiring etc.... The car doesn't seem to bog or anything just a lot of popping.

I will check the plugs this weekend, then maybe replace the module.
 
A few weeks ago I would get 1-2 pops under WOT, now everytime I go completely WOT I get multiple popping/misfiring etc.... The car doesn't seem to bog or anything just a lot of popping.

I will check the plugs this weekend, then maybe replace the module.
Chasing gremlins.......been there is the battery and alternator fine?
 
Could be your ignition module. Make sure you get an ac delco.............

I recently talked with a regional AC Delco manager at a trade show here, and I asked him which factories and where are they located which actually makes their parts?

He stated they do not manufacture any parts now, all their parts manufacturing is out-sourced, mainly off-shore, and of course in Mexico which we have known about for years.

Parts are usually made to their specs, but many of the individual components used in parts like the GN ignition module are no longer available after 30+ years, and the substitute components may or may not perform like the original product.
 
where is the best place to buy the ignition module?
AC Delco is what you want as far as modules go but as Nick pointed out they are now outsourced. Some have success with aftermarket modules but they are hit and miss. The AC Delco modules made by Magnavox (for AC Delco) is the one you want if you want no drama. I have a couple that's been tested with a Caspers Ignition Simulator as well as on my car. So you'll know you're getting one that works. PM me if you need one.
 
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