injector pump question

[rfb343]

Hello, I'm new to the forum, but have looked up answers to a great number of questions in the past now now I need a specific answer, I have a 91 f250 2w 7.3L that wont start, one day I went to goto work and it would not start, this has happened many time to me in the past and has resulted in new GPs, GP relay,fuel filters,8 new injectors and return line kit, each time she ran like a champ alas she has sat for too long and now its time to get her cranked up again... Heres what I know so far(in addition to the above parts being in working order) I have copious(about 2-3 ounces in 5 seconds of cranking) amounts of fuels at the Injector pump inlet, and no fuel at the injectors, am I due for an injector pump or is there something else I should test first? Thank you in advance Mark Taylor

[M.L.S.C.]

IIRC you're supposed to be seeing at least 1 pint of fuel for 10 seconds of cranking, so at 3 ounces per 5 seconds you're like 10 ounces short of that - I didn't see a lift pump in your list of replaced parts, and since that's what delivers the fuel to the injection pump that would be my prime suspect too.

[rfb343]

Originally Posted by M.L.S.C.

IIRC you're supposed to be seeing at least 1 pint of fuel for 10 seconds of cranking, so at 3 ounces per 5 seconds you're like 10 ounces short of that - I didn't see a lift pump in your list of replaced parts, and since that's what delivers the fuel to the injection pump that would be my prime suspect too.

That is correct I have not replaced the lift pump, as I thought It was putting out enough fuel, I will double check the pump output for the above volumes and repost the results, thank you.

[danngreen]

Originally Posted by M.L.S.C.

IIRC you're supposed to be seeing at least 1 pint of fuel for 10 seconds of cranking, so at 3 ounces per 5 seconds you're like 10 ounces short of that -

Thought it was 1/3 pint in 10 seconds, which is 2-3 ounces in 5 seconds, so you should be getting good fuel delivery at least TO the injector. That's about what mine delivers (I just replaced the caps on the injectors and return lines). I got the 1/3 pint in 10 seconds figure from these posts: 1988 7.3 Navistar Camper, cold start issues Start then no start? cranks but won't start

[M.L.S.C.]

I stand corrected, guess I missed that "/3" part, lol - never really had to mess with mine, dunno how much fuel it delivers but judging by how strong the truck pulls even bouncing off the governor tis apparently more than enough fuel

[arthurgoboom]

You may want to test the fuel shutoff solenoid to ensure it's working. Turn the key on and go out and disconnect both wires going to the top of the injection pump. There should be an audible click when you touch the connectors to their respective spade terminals. One is the shutoff solenoid, one is the cold advance solenoid. I don't remember which is which but they both should work.

[M.L.S.C.]

the FSS runs off the plug closer to the injection pump gear cover

[rfb343]

Thanks for clearin up the fuel volume, it seemed to me that it was pump an adequate amount of fuel, I havent had a chance to check the solenoids yet, but I'll check 'em today

[LMJD]

Thought it was 1/3 pint in 10 seconds, which is 2-3 ounces in 5 seconds,

Yea, it's something like that as I remember. I was thinking the pint/minute was a mile off. I don't have time to look it up in my shop manual. Bad part is, you feed some poor guy the wrong advice and he wastes time and money replacing the wrong components.

[M.L.S.C.]

Originally Posted by LMJD

Yea, it's something like that as I remember. I was thinking the pint/minute was a mile off. I don't have time to look it up in my shop manual. Bad part is, you feed some poor guy the wrong advice and he wastes time and money replacing the wrong components.

Oh yeah, that's why I always indicate if I know something for sure,like, if I've personally measured it, or taken it apart - anything else gets the IIRC and AFAIK and similar expressions to go with the info, as that's be something I haven't personally verified, like that fuel flowrate thing now.

[rfb343]

Ok, so I know I've got plenty of fuel getting to the IP, and after recharging batteries have found that the when the two wires on the top of the IP are removed and the ignition on, the one towards the front clicks on and off with removing and replacing the wire, the one in the rear does nothing. Now the the other question is what is the grey plastic module on the side of the IP with a 3 wire plug on the drivers side of the IP? thanks

Mark

[DAVID94IDIT]

If you have an automatic that is probably your MPLS. I senses your trottle position and controls the shifting of the transmission.

[rfb343]

ok, so Im assuming here that the my cold advance solenoid is bad(as the r and r of the wire to the terminal in the rear did nothing) unless im mistaken and have the FSS and cold advance mixed up, in either case what is involved in replacing them, as I cant find anything bout it online or in either of the Haynes books i got.

[M.L.S.C.]

Let's start simple - run a jumper wire from a battery's positive terminal (either battery works) to the FSS spade connector (the one closer to the injection pump gear housing), that should take care of any electrical issues you may have and assure that the FSS is open - now try to fire up the engine, whether it fires up or not should help you rule out possible wiring mismatch.

The 3-wire module on the side of the IP is indeed the FIPL, tis like a TPS but only for the E4OD transmission.