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2631704

I installed Holley's Sniper EFI system on a 1987 420SEL. I got sick of my fuel relay and generally the ke-jetronic system. In the beginning I tuned the EHA to 0.6bar and left it unplugged and ran the car for awhile in 'carb mode' but it would always run its self out of fuel at high rpm.

Pin #4 of the overvoltage relay is deleted so no ecm or airbags. The transmission quickly locked the torque converter clutch at 45mph. I'll mod the air conditioning this weekend and bleed the brakes. The transmission pump is getting new seals soon.

So the throttlebody was replaced with a cast iron t3 2.5" Vband adaptor off ebay. The vband clamps to extended and welded 2.5 to 4.0 vband 'bell'. The top of the bell has a 3/8 mild steel 4150 carb plate from hellsgate and the efi is bolted on top. I installed a honda civic hybrid gas peddle from a previous project so I can run normal cable throttle linkage. The factory linkage seesaws starting at the transmission lever and its opposite side pulls the throttle. The efi runs at 58psi which is a breeze for the factory fuel pumps which are chinese 044 bosch clones off ebay. Factory bosch fuel filter. I plugged the oem injector holes with dimes and RTV. Most important is running a relay off the keyed switch for the positive side of the ignition coil. The relay keeps the voltage clean for the efi while cranking. EFI gets its tach signal from neg side coil. Efi has its own fuel relay spliced directly to the oem fuel wire #7. The overvoltage relay now only powers ABS. The egr thermo vac switch is removed and hole tapped 3/8npt for efi coolant sensor. Carb plate sits just above the temp sensor for the ecu/ignition system and a mrgasket 'lowrider' #4339 air cleaner leaves an inch of clearance under the hood. More to come soon
 

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W201, W212, W221, & W222 Moderator
'84 Euro 500SE, '85 Euro 2.3-16, '51 Euro 170S, '97 Jeep Wrangler Sport, '15 G63 AMG
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What are the differences you've noticed in terms of mileage, power, and idle stability?
 

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Discussion Starter #4
The odometer is stuck at 122k and I haven't a clue yet. I'll get a GPS speedo/odo and check. The power usable. I can survive on-ramps and hit 85mph in a normal amount of time. The oem throttlebody sensor is unplugged and the ezl assumes i'm always at 50% throttle. Idle is a little bouncy in park but in drive its a solid 700rpm. I used to pull up to stoplights and the engine would die with oem KE-Jet. Now it idles like it should. I reworked the throttle and transmission cables today.
 

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W201, W212, W221, & W222 Moderator
'84 Euro 500SE, '85 Euro 2.3-16, '51 Euro 170S, '97 Jeep Wrangler Sport, '15 G63 AMG
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8,511 Posts
I see. In Drive my idle would be around 350RPM after the car warmed up due to a failed throttle position sensor that someone just decided to short the pins to. I've removed that jumper and am now always at 700 in Drive, but I can tell it's running richer now, but no more bogging down at stop signs with the AC on.
 

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Discussion Starter #7
nice, ya I fabbed an IAC delete tube before the efi install. the tube worked well enuf for putting the car in carb mode.
 

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Discussion Starter #9
ran a volvo alt for the past 3 months. it was $50 at a salvage yard. its a genuine bosch alt from a 1991 volvo 240. 80amp double pulley.
2637261

the al157x gets a grind on its housing and a spacer to fill the other side's gap.
2637265

al129x - al157x - OE 0120469588589
2637266

2637277

air pump delete

2637280

the volvo alt only put out 13.4v on a hot day. the new al129x sends a solid 14.2v all day because its 115amp and has a fresh chinese voltage regulator.
 

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Discussion Starter #10
2637669

use the right hex key and you wont have to drill this bolt. rockauto mixed bag of AC orings.
 

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Discussion Starter #11
2638203

2638204

1975 bronco reluctor wheel is the same as MSD uses in their dis. The pick-up is off a chrysler town & crunchy station wagon or gran fury. The magnet and metal that lives inside the coil has been bent and shaved and mounted the edge of the dist. I placed the pickup 45 degrees behind cylinder #1 as the Sniper instuction say to do so. Tomorrow I'll swap out and wire the Sniper for magnetic pickup instead of "coil negative" triggering. If this deal works then i can use the 'points out' wire to trigger a coil driver to trip the coil negative using programming within the Sniper CPU fully controlling engine timing and I'll be able to delete the EZL. Brown sniper wire goes to the benz TD wire which I think means "tach drive". I still need td for air conditioning i think. AC is blowing cold right now. I activated the over pressure blow off valve hahaha. So the dis shaft that makes contact with the rotor is 14.6mm and the lower part is only 12mm. The reluctor's interior diameter is 16mm or 0.625 inches. Roll pins 5/64ths of an inch or 2mm. I think it took 21 pins and I taped and rubberbanded these around the lower shaft. I hammered the reluctor wheel on because 2+2+12=16. It spins perfectly. I then scratch strart tig welded around the top with 308l rod. I'm sure the reluctor wheel is 409ss and the shafted is unknown but puddled right. I did all this to a $25 'rebuilt unit' off of ebay.
 

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Discussion Starter #12
2639473

hogged out everthing and i still cant get a clean signal. gonna try an HEI module next
 

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Discussion Starter #13
I give up on magnetic pick-up. Ordered a dist for a 1995 5.0 mustain and gonna see if it fits. Holley hyperspark is a clean version of a 5.0 dist from years 88-95ish. Hall effect and a 12v square wave should make the sniper happy.
 

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Discussion Starter #14
The air conditioning's 12v to compressor clutch is now actuating a relay the grounds the orange 'A' input of the snipe's 10 pin connector and the sniper bumps the IAC by 15% to idle up the engine at redlights. it blows cold.
2639846
 
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