20V MK1 Engine Swap Injector resistor for a silvertop in a 1985

IkoIKo · 07-17-2009, 12:00 AM

I have a 85 MR2 with a silvertop 20 valve installed. The wiring for my car was done by someone else.
Mr220v mentions in one of his posts about wiring the injector resistor for a 20 valve swap into 1985 cars. Is this something that can be done after the install?

Kerry Phillips · 07-17-2009, 02:44 PM

The silvertop uses sequential fuel injection, Each injector is controlled independantly. The 85-87(early versions) MR2's used slightly different injectors that required some resistance to operate from a 12volt source.
The silvertop does NOT require such resistance.

Technical note:

The haynes manual refers to the part as a resistor, in the electronic world that part would be called a resistor network-it is actually TWO resistors with one common end.

BTW, enjoy NOT having to make your own wiring harness!

mr220v · 07-17-2009, 02:58 PM

Quote:

Originally Posted by kerry Phillips

The silvertop does NOT require such resistance.

Correct, 20v's do not require injector resistors.

IkoIKo · 07-17-2009, 06:55 PM

Thanks for the reply.
I was hoping that was the source of this engine running too rich. (Black tailpipe, popping after throttle lift off) It's developed a bad habit of running rough at idle and sometimes even shutting off.
I did some more checking (spray carb cleaner looking for vacuum leaks) and found that I could get the engine to shut off when I jiggled the connection on the AFM. So I bought another AFM from a 89 Camry 4 cyl. (based on the suggestions found on this board - thanks again). With the two AFMs next to each other I found another problem! The inlet on the AFM that came with the engine is WAY bigger. I looked up the part number on line it appears to be for a 3SGE turbo. So, I'll get some new adaptors and slap that in. Maybe that was the problem all along.

07-17-2009, 12:00 AM	#1 (permalink)
IkoIKo No Skills Join Date: Jun 2009 Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (2/100% )	Injector resistor for a silvertop in a 1985 I have a 85 MR2 with a silvertop 20 valve installed. The wiring for my car was done by someone else. Mr220v mentions in one of his posts about wiring the injector resistor for a 20 valve swap into 1985 cars. Is this something that can be done after the install?

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07-17-2009, 02:44 PM	#2 (permalink)
Kerry Phillips Cage Fighter Join Date: May 2006 Location: Chattanooga, TN area Posts: 299 Thanks: 0 Thanked 21 Times in 21 Posts iTrader Rating: (0/0% )	The silvertop uses sequential fuel injection, Each injector is controlled independantly. The 85-87(early versions) MR2's used slightly different injectors that required some resistance to operate from a 12volt source. The silvertop does NOT require such resistance. Technical note: The haynes manual refers to the part as a resistor, in the electronic world that part would be called a resistor network-it is actually TWO resistors with one common end. BTW, enjoy NOT having to make your own wiring harness!

07-17-2009, 06:55 PM	#4 (permalink)
IkoIKo No Skills Join Date: Jun 2009 Posts: 17 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (2/100% )	Thanks for the reply. I was hoping that was the source of this engine running too rich. (Black tailpipe, popping after throttle lift off) It's developed a bad habit of running rough at idle and sometimes even shutting off. I did some more checking (spray carb cleaner looking for vacuum leaks) and found that I could get the engine to shut off when I jiggled the connection on the AFM. So I bought another AFM from a 89 Camry 4 cyl. (based on the suggestions found on this board - thanks again). With the two AFMs next to each other I found another problem! The inlet on the AFM that came with the engine is WAY bigger. I looked up the part number on line it appears to be for a 3SGE turbo. So, I'll get some new adaptors and slap that in. Maybe that was the problem all along.