Sniper EFI
#51
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Re: Sniper EFI
Had my first start up with the distributor today it was a mixed bag of success and failure. I left a bunch of the wires really long just to test it before I bundled everything together. Discovered some nasty emi issues and I started to fix them. Hoping that I will have it all sorted out soon. The biggest emi issue seems to be coming from my 12-volt ignition source. I had previously used an isolation relay for the throttle body unit. I wired in a second isolation relay for both the distributor and the CDI box. Putting both of those things on the same 12 volt line was a mistake I am now isolating them separately and keeping the distributor 12 volt line as short as possible. When I was having emi issues having the air filter installed was causing my system to lose track of all the sensors stall out and backfire. Next time I get back to the shop I will clean up as much wiring as I can and find the best place for everything to hopefully avoid future emi issues.
#52
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Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: Sniper EFI
yes, these units are very susceptible to RMI and EMI noise. One thing people also do to help quell it, is the use of those ferrite beads that simply clip-on to the wire sheath.
https://resources.altium.com/p/how-d...oose-right-one
https://resources.altium.com/p/how-d...oose-right-one
#53
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Re: Sniper EFI
Tried a couple ferrite beads in a few places definitely improved performance. I also grabbed some emi shielding that can go over wires in case I need it. But I am still having emi issues one suggestion I've gotten is to change spark plug wires unfortunately they're running late because the USPS blows. I may also have to get the plastic air cleaner stud but we'll see once I get the new wires. While I had a little down time waiting I did make a little RFI shield. No idea if it will help but why not. You can see in the graph everything's going decent then all of a sudden reset. I'm very surprised for years I had no RFI issues now with the new distributor I do I guess I got lucky
#54
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Re: Sniper EFI
Went back to troubleshooting today was still having issues so I decided to redo all my wires again see how far away I could get everything. When I went to start again my LCD said no ECU no data everywhere. I went through and inspected everything and the main fuse turned out to be loose I think it was the cause of a lot of my problems. Tightened up the terminals and put it back in now it seems to be running great. Still need to get everything together and take it for a test drive but I looked at my old logs and holy crap the battery voltage was being weird. Did a six and a half minute test moving things around trying to get it to fail and no issues. I'm still going to swap out to the better plug wires when they come and I will probably leave the ferrite beads that I put on in there. Not sure if I will leave the emi shield I made. But really happy to make some progress
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#55
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Car: 1988 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 10 Bolt 2.73 Open
Re: Sniper EFI
Nice catch! Sometimes it's the simplest things. Although by reputation, I'm sure your shielding efforts were not wasted.
#56
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Re: Sniper EFI
Did some more work tonight and ran the car for many minutes letting fans cycle on and off a few times. Absolutely no issues started and restarted easily no stalling. So I started cleaning up some of the wiring and bundling it no problems were caused. Battery voltage was still nice and steady I'm very happy should be ready for spring
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DynoDave43 (03-14-2024), IROCZman15 (03-20-2024)
#57
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Re: Sniper EFI
170 miles of testing later and no issues the car is running nice and responding good to timing changes. Right now running 27 idle 34 WOT and 40 cruise with the table smoothed a bit. Need more testing and a mpg check but I am happy
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