HICKL Posted April 2, 2003 Share Posted April 2, 2003 I was chattin with my nieghbor yesterday and he mentioned that he had let his old truck sit up for a year and had to put his old carb back on to get it running. As I am in need of a carb, I asked what he took off of it. Turns out he had a 670 cfm pro-jection fuel injection system on the 71 chevy pickup. Anyway, I took it apart an the injectors are just a little gunked up. We didn't discuss $$, but I think I can get it pretty cheap. What do you guys know about this system. My motor is a relatively mild, 300 hp if I'm lucky, sbc 350. Can list more details if necesary. Thanks for any input. Jeff Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 2, 2003 Share Posted April 2, 2003 Mr Hickl; Very interesting and maby a real good deal for you if the price is right. Soon others will come in here and clue you in as to it's worth etc.. I would think it wouldm't be to much to get it going. Check for cracks and what are the injector numbers? If it's ok and you don't want it, make a few bucks. Quote Link to comment Share on other sites More sharing options...
Guest thepenguin99 Posted April 2, 2003 Share Posted April 2, 2003 I could be wrong but I think the 670cfm 2barrel setup is good up to ~300hp but thats just about it. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 2, 2003 Share Posted April 2, 2003 Yup, you should be OK with that unit for your current application, but You'd outgrow it if your powerplant grew new aluminum heads or freer flowing exhaust, or a new cam or.... You get the Picture... Those things are dead nuts reliable from what I've read, just don't make the most power available... Mike Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted April 2, 2003 Share Posted April 2, 2003 You should find out if it is the old analog type, the 4D system or the 4Di system. The analog system had a control box with 4 or 5 dials on it. They were OK I guess, maybe little easier to tune than a carburetor. The 4D system was a digital system but you needed a calibration module to tune it. It should have "4D" on the ecu. I think it also had an O2 sensor feedback. The 4Di was Holley's first full laptop programmable system with spark control. I have one in my car now. It is primitive as fuel injection goes, but with patience it can work great. Their new Commander 950 systems are supposedly world class EFI, finally. Quote Link to comment Share on other sites More sharing options...
HICKL Posted April 2, 2003 Author Share Posted April 2, 2003 It has the control box with 5 dials on it. Choke, idle, mid range, top end and one more which I can't remember. It is probably a 10 yr old system. Does anybody now how much the injectors are in case I need to replace them? Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 2, 2003 Share Posted April 2, 2003 I've got the Commander 950 for a TPI setup and it is a vey nice package... Can't wait to install it! Mike Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted April 2, 2003 Share Posted April 2, 2003 It has the control box with 5 dials on it. Choke' date=' idle, mid range, top end and one more which I can't remember. It is probably a 10 yr old system.Does anybody now how much the injectors are in case I need to replace them?[/quote'] Sounds like the same unit I bought new back in '90 or '91 for an '80 El Camino I had. I also bought their closed loop system for that 4D. It ran great, and really enjoyed it. That was my first EFI and have never looked back. I try to avoid carbs now. Quote Link to comment Share on other sites More sharing options...
HICKL Posted April 2, 2003 Author Share Posted April 2, 2003 Lets get technical for a minute. I am trying to determine if the injectors can be unclogged before buying new ones or installing the whole system and having it not spray. The injector is basically a cylinoid (sp) that opens when given the proper voltage. To bench test and clean these buggers I could apply the voltage and see if it opens and spray through it. Anybody know what kind of voltage this thing expects to see at the injector???? I know I'm reachin here, but I figure the injectors are pretty pricy so it's worth a little fiddlin. Jeff Quote Link to comment Share on other sites More sharing options...
Mike kZ Posted April 2, 2003 Share Posted April 2, 2003 Check here for Holley EFI install and trouble shooting manuals: http://www.holley.com/HiOctn/TechServ/TechInfo/FMFITech.html Quote Link to comment Share on other sites More sharing options...
HICKL Posted April 2, 2003 Author Share Posted April 2, 2003 Thanks for the link, but I didn't find the info I needed. Anybody have the answer??? Quote Link to comment Share on other sites More sharing options...
Guest Thurem Posted April 3, 2003 Share Posted April 3, 2003 You might be able to get the injectors sonically cleaned (atleast I think thats what it's called). My buddy gets it done for 25 $ per injector, he is a mechanic. I would say to look in the Yellowpages. Thure Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted April 3, 2003 Share Posted April 3, 2003 If you want to bench test the injectors the best way is to hook up the entire system as if it were in a car. You will need 15 PSI fuel pressure to the throttle body. Once everything is wired, it should start spraying as if it were on idle. One difficulty may be to simulate the distributor signal, but you might be able to use a running engine. You shouldn't just apply straight voltage to the injectors because they operate on a pulsed signal. Full injector voltage (100% duty cycle) may fry the coil. Quote Link to comment Share on other sites More sharing options...
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