Page 3 of 7 FirstFirst 1234567 LastLast
Results 31 to 45 of 95

Thread: Another Conversion

  1. #31
    Fuel Injected!
    Join Date
    Mar 2017
    Location
    Sacramento, ca.
    Age
    42
    Posts
    51
    I do not have a book per say. but I do have the downloaded wiring diagrams for the 91 Chev Astro 4.3l auto. I do not know if the oil press switch is looking for the same pressure as what my l6 original pump puts out.
    Also the prom is Delco AUMJ 1278 underneath it has
    JT8(G)/J6/P
    LFIVN960
    AE03

  2. #32
    Fuel Injected!
    Join Date
    Dec 2014
    Location
    Saint John, NB, Canada - beside Maine
    Age
    75
    Posts
    22
    Thanks for the information - that's a lot to put on a small part. I think oil pressure should be about the same for the 250 and the 4.3. So oil light on at idle causes can be, besides actual low oil pressure from engine wear - oil pressure not getting to switch, due to passage obstruction, switch failure, oil too thin from gas dilution, and idle speed too low. Any of those possible? Does the light go out as engine speed increases? Are the valves noisy?

  3. #33
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    it depends on what oil I use ,my 4.3 has 20-35 psi at idle .

  4. #34
    Fuel Injected!
    Join Date
    Dec 2014
    Location
    Saint John, NB, Canada - beside Maine
    Age
    75
    Posts
    22
    Sounds healthy. I'm told that the pressure switches for dash lights turn the lights on below 7 p.s.i. Does yours have the factory gauge setup?

  5. #35
    Fuel Injected!
    Join Date
    Mar 2017
    Location
    Sacramento, ca.
    Age
    42
    Posts
    51
    Well. The old sensor came on when oil got too low (valve cover leak I have not been able to seal yet. Prolly going to replace the cover.) I do not know if this sensor is any good so I'll probably replace it. My engine w/o fan is really quiet compared to when my dad had it running. Haha

    Although thinking about it the oil pressure switch that I pulled from the Chevy Astro van appeared to have a piece of plastic tube snapped off inside of it I might go pick another one up for $20
    Last edited by r.e.c.enthusiasts; 08-16-2017 at 06:12 PM.

  6. #36
    Fuel Injected!
    Join Date
    Mar 2017
    Location
    Sacramento, ca.
    Age
    42
    Posts
    51
    Quote Originally Posted by 53 Catalina 292 View Post
    Sounds healthy. I'm told that the pressure switches for dash lights turn the lights on below 7 p.s.i. Does yours have the factory gauge setup?
    Nope. Just came w dummy light

  7. #37
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    I have a electric dash gauge [stock] . them sender units may operate at different psi I don't no.

  8. #38
    Fuel Injected!
    Join Date
    Dec 2014
    Location
    Saint John, NB, Canada - beside Maine
    Age
    75
    Posts
    22
    r.e.c.enthusiasts - Maybe, instead of spending $20. on a new oil pressure switch, you could try walking into the parts store with a straight face and asking if you could just borrow one for a couple of hours. Sometimes the guys like to kid around. Good luck with that. My mental image of the engine end of the perfect oil pressure switch doesn't have any snapped off plastic tube, so you may be on to something. I've had a few of those "Oh, yeah, now that I think of it..." moments. Sometimes I say, "I knew that! I did!" Is the oil pressure gauge involved in the TBI or ignition wiring? Just thinking that if you had a mind to put a gauge in someday, and it's not wired into the TBI or ignition controls, this could be a good time. I know one Chevy system in a previous century would cut power to the fuel pump if the oil pressure was inadequate. Three terminals on those switches, I think. How many on the Astro switch?

  9. #39
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    it depends on what year and model if it is hooked to the fuel system.i think you can bypass all that if you no how.

  10. #40
    Fuel Injected!
    Join Date
    Mar 2017
    Location
    Sacramento, ca.
    Age
    42
    Posts
    51
    Well... Its the 3 wire pressure switch from the 91 vin z astro van and it is wired in with the fuel pump. The truck does start and run. The oil light stays on full time though

  11. #41
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    that switch is proble for a gauge,

  12. #42
    Fuel Injected!
    Join Date
    Dec 2014
    Location
    Saint John, NB, Canada - beside Maine
    Age
    75
    Posts
    22
    That would be great, to replace the switch and find out you don't have an oil pressure problem. Did the donor Astro have a gauge?

  13. #43
    Fuel Injected!
    Join Date
    Dec 2014
    Location
    Saint John, NB, Canada - beside Maine
    Age
    75
    Posts
    22
    I just checked Rock Auto's listings - not infallible, but a great encyclopedia, and for the 91 Astro, they list only switches for gauges, suggesting the conclusion that all 91 Astros were gauge equipped. This presents a small problem. ony's suggestion of bypassing the oil pressure switch's control of the fuel pump sounds good to me. If that is workable, a one-wire oil pressure switch should operate the light. At least, that's how they did it in the salad days of the 250. I think the 250 switch was normally closed, completing the ground circuit, putting the light on, and when pressure came up, it opened, leaving/turning the light off. I'll check other listings and, ahem, report my findings.

  14. #44
    Fuel Injected!
    Join Date
    Dec 2014
    Location
    Saint John, NB, Canada - beside Maine
    Age
    75
    Posts
    22
    Herewith, ahem, I am pleased to report my findings: Under 1989 Caprice, with dash light, I find Airtex/Wells part no. 5G7 and Standard part no. PS212T, each using 3 wires, and each way under $10. before shipping. I chose the one with the small, long base, remembering that the hole in the block of my 292 is deep in a recess below the side cover. As long as your connecter plugs into it, you should be in business. If you check Rock Auto, under 89 Caprice, Electrical, Switches and relays, you can pull up pictures to see if your plug matches.

  15. #45
    Fuel Injected!
    Join Date
    Dec 2014
    Location
    Saint John, NB, Canada - beside Maine
    Age
    75
    Posts
    22
    Did you try replacing the oil pressure switch with one calibrated , if that's the fancy word I want, for a light instead of a gauge? And I'm thinking that you will need the temp gauge sender calibrated for a light, too. Is there a reason you don't want to use the original location in the cylinder head for the temp sender? Maybe you want one location for the light and one for a switch for an electric cooling fan? (Good plan, in my view.)
    Other than the manifold adapter and the distributor, which you've posted about, what were the other issues you ran into before getting the TBI system running? I'm hoping to find an Astro/Safari or other 4.3 donor for the PCM, or maybe just the PROM, to run my Caprice system for my conversion. Johnny Cash would be so proud. But 4.3s of that vintage are few and far between hereabouts. There's one I see nearby, but it's still in service, so if I were to appropriate the PCM, I figure the guy would miss it sooner or later. (Comedians everywhere looking for work, and I'm trying to be funny. Shame on me.)

Similar Threads

  1. TBI conversion.
    By scottsrc in forum Introductions
    Replies: 5
    Last Post: 01-23-2015, 09:37 PM
  2. 24X LT1 Conversion
    By MYLTWON in forum OBDII Tuning
    Replies: 0
    Last Post: 12-28-2014, 06:32 PM
  3. 4A-GZE conversion
    By ericjon262 in forum GM EFI Systems
    Replies: 16
    Last Post: 11-24-2014, 05:37 AM
  4. s-10 283 tbi conversion
    By hammertime371 in forum GM EFI Systems
    Replies: 30
    Last Post: 09-15-2014, 06:26 AM
  5. My First EFI Conversion
    By EagleMark in forum GM EFI Systems
    Replies: 1
    Last Post: 09-18-2011, 04:00 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •