Injector Questions and some "What If's"
02-05-2011, 11:25 PM
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Injector Questions and some "What If's"
I have a "new to me" 1986.5 928 auto, 85,000 miles, that I am in the process of restoring to a roadworthy condition. Am in the process of refurbishing the ignition parts and thinking ahead to the fuel system.
Looking through previous posts it seems logical to replace the existing injectors with the Ford 19# units but I have a couple of questions.
1. What Ford part number? Do the stock o-rings fit my motor or do they need changed? What part number for Injector? O-Ring if needed?
2. A more critical question - I am considering updating the exhaust with an X-pipe. Will I need a different Injector if I do that? What size is recommended?
3. Even more critical question - If I install a Porken performance chip will I need a different injector? What size?
4. Ultimate critical question - If I install both the X-pipe AND the performance chip? What size injector works best with that combination?
I appreciate any advice and all comments. Have been reading through the forum til way past bed time every night. Too much info to absorb without serious danger of head explosions!
Looking through previous posts it seems logical to replace the existing injectors with the Ford 19# units but I have a couple of questions.
1. What Ford part number? Do the stock o-rings fit my motor or do they need changed? What part number for Injector? O-Ring if needed?
2. A more critical question - I am considering updating the exhaust with an X-pipe. Will I need a different Injector if I do that? What size is recommended?
3. Even more critical question - If I install a Porken performance chip will I need a different injector? What size?
4. Ultimate critical question - If I install both the X-pipe AND the performance chip? What size injector works best with that combination?
I appreciate any advice and all comments. Have been reading through the forum til way past bed time every night. Too much info to absorb without serious danger of head explosions!
02-05-2011, 11:30 PM
#2
Administrator - "Tyson"
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There is absolutely no reason to go down to 19lb injectors.
1985/86 cars use 24lb injectors. You cannot go to 19lb unless you plan on re-tuning the engine and / or adjusting fuel pressure to compensate.
It is a good idea to have your injectors cleaned / flow matched. I've used both of these places with good results:
http://www.cruzinperformance.com/
http://www.witchhunter.com/
None of the modifications you listed will need larger injectors. If you need more fuel a RRFPR (rising rate fuel pressure regulator) would be a better way to go than jumping up injector sizes.
Welcome to the club - sounds like you've already figured out the search function so I won't go into my normal diatribe about it.
1985/86 cars use 24lb injectors. You cannot go to 19lb unless you plan on re-tuning the engine and / or adjusting fuel pressure to compensate.
It is a good idea to have your injectors cleaned / flow matched. I've used both of these places with good results:
http://www.cruzinperformance.com/
http://www.witchhunter.com/
None of the modifications you listed will need larger injectors. If you need more fuel a RRFPR (rising rate fuel pressure regulator) would be a better way to go than jumping up injector sizes.
Welcome to the club - sounds like you've already figured out the search function so I won't go into my normal diatribe about it.
02-06-2011, 01:31 AM
#3
Rennlist Member
You can use the 87 S4 fuel regulator (Ken indicates that on his site). Direct fit.
The dampers also changed for 87 with the higher pressure, but most of us are using the stock 85/6 ones without issue so far.
The dampers also changed for 87 with the higher pressure, but most of us are using the stock 85/6 ones without issue so far.
