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engine backfire issue
Posted: Sun May 01, 2011 1:01 pm
by Pinzgauer Pete
Have a new issue that just developed...Pinz runs great when first started and engine is cold...then after a few miles starts running poorly and bacfires....I literally have to keep fanning the accelerator pedal to keep it from stalling almost like it is not getting enough fuel but then loads up and backfires. I suspect an ignition problem maybe a bad coil??? or could this be a sign of an impending pertronix ignition module going bad??? I thought if the pertronix module goes bad it would just fail and not start at all...maybe someone out there had the same issue and resolved it?
Re: engine backfire issue
Posted: Sun May 01, 2011 4:53 pm
by spandit
Is it misfiring? Does sound like an ignition problem. Try running your engine at night and looking under the cover (or take it off) to see if there is any sparking - could be an HT lead breaking down etc.
My misfire, I think, was caused by a dodgy coil connection so try unplugging the terminals and plugging them back in again, making sure the crimps are in good condition.
Re: engine backfire issue
Posted: Sun May 01, 2011 5:02 pm
by totaljoint
My backfire was caused by an exhaust leak (thanks, Jim L.!), the gaskets between the header and pipes finally burned through. Replaced with NAPA equivilent and now sounds and runs better than ever.
Re: engine backfire issue
Posted: Sun May 01, 2011 5:05 pm
by spandit
I do need to sort my exhaust out as it is leaking a bit too. Can you post the NAPA part number or a picture of said gaskets?
Re: engine backfire issue
Posted: Sun May 01, 2011 5:17 pm
by Pinzgauer Pete
I thought it could be an exhaust leak too but the fact that it runs normally when cold and only acts up when hot lead me to believe it may be an item like a coil or module that is breaking down with the heat..dont think exhaust gaskets could behave that way..
Re: engine backfire issue
Posted: Sun May 01, 2011 5:35 pm
by Jim LaGuardia
Main cause of coil failure is excessive voltage(bad regulator). Could be domino effect starting with dirty molex connection overworking regulator, voltage above 28.8V dc will cook the coil over time.
Use a VW Beetle coil (aka Bosch Blue coil). It will have 3.3-4.0 ohms resistance. Do not use any coil with
less than 3.0 ohms or the Pertonix module will fail

Re: engine backfire issue
Posted: Sun May 01, 2011 8:12 pm
by edzz
Any chance you still have one of the Pertronix Epoxy coils that were recalled?
http://www.expedition-imports.com/categ ... il_recall/
Re: engine backfire issue
Posted: Sun May 08, 2011 8:56 pm
by Pinzgauer Pete
Ok finally got to work on the Pinz this weekend...as I thought this was indeed a ignition issue. I had a blue vw coil laying around and changed it out. For good measure to make sure I did not have a bad voltage regulator I checked that and found the voltage to be within spec outputting 28.05volts. Runs great now no more backfiring!
Re: engine backfire issue
Posted: Mon May 09, 2011 12:20 am
by wudog
I had the same problem about a month ago. Thanks to Jim L, he solved the issue OVER THE PHONE with me, replaced ignition coil. I have a Bosch Blue coil on and carrying a spare coil just in-case.
Re: engine backfire issue
Posted: Thu May 12, 2011 6:44 pm
by Skeej
spandit wrote:I do need to sort my exhaust out as it is leaking a bit too. Can you post the NAPA part number or a picture of said gaskets?
Me too!
Re: engine backfire issue
Posted: Thu May 12, 2011 10:45 pm
by totaljoint
Sorry guys, no part numbers. Here's what the mechanic I had do the work told me:
I tried to locate the NAPA part numbers, there are none. Seems that you have to go through boxes of gaskets in the back with the ring (part #14 on assembly group 01-55) and old gasket ( be sure and catch the NAPA guy on a good day where he'll let you search for a while) and see what makes the best fit, but none had part numbers. On mine two different sizes came very close, so out of 4, I have two of each size...seems to work fine though.
On mine, it was a gasket that came in doubles (two/sheet)) and they had to be cut apart and the mounting holes modified.
Not worth it, considering that SAV has them for around $4.80/ea in stock. NAPA price was 3.00/ea.
Sorry I couldn't be of more help.
Ed
Re: engine backfire issue
Posted: Fri May 13, 2011 8:41 am
by pinzinator
When a condensor fails you will have a backfire and loss of power. I should know, I've had it happen twice, once was with my Haflinger. Start with the cheapest and easiest fix first.