Fuel pump problem...I think

Here are all of the best threads. Alert an admin to nominate a thread

Moderator: Staff

Re: Fuel pump problem...I think

Postby powndpuppy » Thu Jun 13, 2013 2:57 pm

Has anybody done a swap from the 2.6 izoozoo-electro-whizzer-leave-you-on-the-roadside-engine to the GM V6? How about to the 23.carbureted engine. Do the car and intake from the 2.3 bolt to the 2.6? I know that the exhaust manifold does. With the GM V6, did you have to change trannies too and how is the difference in mileage and performance? I've had it with the garbage electronics on this 2.6. I live where the daytime temps are over 100 deg. virtually every day in the summer, all summer and often as not, below freezing in the winter, and I can't have a car that will leave me sitting and baking in a canyon 40 miles from the nearest cow (who died 3 years earlier from heat stroke). I need something r-e-l-i-a-b-l-e. zoozoo electronics just don't pass the sniff test for me anymore. Even though I carry a plethora of tools, it is hard to field-rig a new brain or electronic fuel injection circuit in the field, using a matchbook and a pair of paperclips. Even McGuyver would find himself flustered and cussing at and kicking this POS.

I found the fusible links, I think. They're little plastic boxes with clear tops, screwed into the input side of the fuse panel. They're fine and the panel is hot.

I found my fuel pump circuit. It runs from the under the dash fuse panel, under the floor mat, exiting the floor under the PAX seat in a design that I'd call "at best, horribly flawed". The through the floor plug is down in a low spot that would hold water and submerge the connector in deep fording. (Maybe OK in fresh water, definitely BAD in salt, and something as simple as a window cracked in a car wash would flood the depression). I ran power to the fuel pump circuit and it runs. The pump is new and it does push fuel. I have power to the coil with the key on, but no spark. I traded out the coil and tested the one that came off. It was good. I replaced the brain with another used brain. Still no start. Next will be the distributor, I have power to the coil but it isn't sparkling. I'm thinking "bad reluctor in dist. not grounding circuit on rotation". After that comes the torch and engine hoist.

What a can of worms. I'm going to put my old Scout II back on the road and just use this thing as a urinal.
powndpuppy
Drives on Pavement
 
Posts: 10
Joined: Wed Sep 19, 2012 1:57 am
Has thanked: 0 time
Have thanks: 0 time

Sponsor
 

Re: Fuel pump problem...I think

Postby kreepnSlayer » Mon Aug 12, 2013 12:27 pm

Great page.
Going to try some of these suggestions here. I've been having intermittant issues with my fuel as well.
I have a 1991 trooper with the 3.4 swap. While driving it quit on me and I had to two it home. I tried a few times to mess with things but it just wouldn't start. One day I was screwing around under the hood and left the MAP sensor disconnected. It started but ran rough. I plugged the sensor back in while it was running and the car died. I Unplugged it and it started up again. I remembered that I had another sensor from when I did my swap (one came on the 3.4) so I hooked that up and presto, trooper started and ran great.

Last weekend however no dice. Went to start it and nothing. Unplugged the MAP sensor and still wouldn't start. Very strange. It'll crank and crank but won't spray gas.
I'll try all the methods in this thread and post results.
kreepnSlayer
Drives on Gravel
 
Posts: 40
Joined: Mon Aug 12, 2013 9:23 am
Location: Blaine WA
Has thanked: 0 time
Have thanks: 0 time

Re: Fuel pump problem...I think

Postby captkai » Wed Mar 05, 2014 12:18 am

Electronic Engine Control 2.6L.jpg
This is a deep subject! I'm running the jumpered from a keyed slot right now. I have been having issues with my truck not starting if it has been raining or cold for some time now. I won't bother anyone with my various trials; I'll just state what I found, maybe it applies to others.
1.Fuel pump relay socket was only hot in one slot; there should be 2 hot sockets.
2.the yellow wire that runs from the oil pressure switch to the diode to the fuel pump relay was just touching the oil pressure switch (poor connection)
3.I jumpered the yellow wire up by the fuse/relay box to the + on my battery and I got two hot slots in in the fuel pump relay socket
4. Installed the relay and the truck started right up
5. I reconnected the yellow wire connection because there is a blue wire in there also and I don't know what it does yet.
6. The jumpered relay slots is only temporary and probably dangerous. The fuel pump will continue to run and pump fuel in an accident as long as the key is on!
7. I have attached the schematic I used.
You do not have the required permissions to view the files attached to this post.
1990 Extended Cab Isuzu Pickup, 2.6 L 4ZE1; 5 speed 4WD
1994 Isuzu Trooper 3.2 L SOHC automatic
captkai
Drives on Gravel
 
Posts: 48
Joined: Fri Sep 21, 2012 3:29 pm
Has thanked: 32 times
Have thanks: 2 times

Re: Fuel pump problem...I think

Postby bendorfold » Wed Mar 05, 2014 2:22 pm

captkai wrote:I'm running the jumpered from a keyed slot right now.
I have been having issues with my truck not starting if it has been raining or cold for some time now.
Answer: If it's just a "raining or cold" problem. I use kerosene and a paint bush to "wash" the distributor cap and rotor, inside and out, and the wires. WD40 might do the same. This technique eliminates the spark shorting to ground until the parts dry out. Note for cold only: a low compression, 75 psi or less, makes for hard starting when cold.

1.Fuel pump relay socket was only hot in one slot; there should be 2 hot sockets.
Answer: The fuel pump relay only has one "hot at all times" connection. The other one that gets hot is, after the engine is running and the alternator is working, through the engine/charge relay. When cranking/starting the engine, the fuel pump gets its power from the started relay through one of the fuses in the small group of four to the front of the relays.

2.the yellow wire that runs from the oil pressure switch to the diode to the fuel pump relay was just touching the oil pressure switch (poor connection)
Answer: The oil pressure switch, with two yellow wires, will shut the engine off if/when the oil pressures get low so you don't ruin the engine.

A bad alternator is a very common "won't stay running" cause. Symptoms are: engine starts, runs for a couple of seconds and stalls. This is repeatable, start and stall, start and stall. The jumper "fix" will, as Selahdoor said," this will get you home. And/or get you to your next paycheck."
"Use it up. Wear it out. Make it do. Or do without." War Advertising Council: May, 1944

"It is better to keep silent and be thought a fool than to speak and remove all doubt." - maxim

mine - 1989 Trooper, 2.6L, 5-spd Manual, 170,742 miles, Stock - SOLD
my son - 1992 Trooper, Auto, DOHC, 225,000 miles (362,102 km), Stock -Still Good
mine - 1996 Trooper, 5-spd Manual, SOHC, 163,849 miles, Aisin Manual Hubs - Totaled
Isuzu mechanic during 1988-1992 Model Years

For this post the author bendorfold was thanked by:
captkai
User avatar
bendorfold
Zu Royalty
 
Posts: 1050
Joined: Sun Jul 02, 2006 4:24 pm
Location: near, but not in, Philadelphia, Pennsylvania USA
Has thanked: 0 time
Have thanks: 11 times

Re: Fuel pump problem...I think

Postby captkai » Fri Mar 07, 2014 3:45 am

Thanks for your answers; I put the relay back in (yellow wire still broken off at oil Press sensor). It has been starting fine all day; next time it won't start after being rained on I will do the jumper test. But in the meantime I better get my windshield resealed-maybe dry wires would help!
1990 Extended Cab Isuzu Pickup, 2.6 L 4ZE1; 5 speed 4WD
1994 Isuzu Trooper 3.2 L SOHC automatic
captkai
Drives on Gravel
 
Posts: 48
Joined: Fri Sep 21, 2012 3:29 pm
Has thanked: 32 times
Have thanks: 2 times

Re: Fuel pump problem...I think

Postby captkai » Fri Mar 21, 2014 12:44 pm

Does anybody know what this little electrical component does? I appears to be connected in parallel with the fuel pump. (see arrow)
You do not have the required permissions to view the files attached to this post.
1990 Extended Cab Isuzu Pickup, 2.6 L 4ZE1; 5 speed 4WD
1994 Isuzu Trooper 3.2 L SOHC automatic
captkai
Drives on Gravel
 
Posts: 48
Joined: Fri Sep 21, 2012 3:29 pm
Has thanked: 32 times
Have thanks: 2 times

Re: Fuel pump problem...I think

Postby Apeiron » Fri Mar 21, 2014 12:50 pm

bendorfold wrote:
captkai wrote:Answer: The oil pressure switch, with two yellow wires, will shut the engine off if/when the oil pressures get low so you don't ruin the engine.


If the schematics are correct the oil pressure switch will not shut off the pump on low oil pressure, it will keep the pump running as long as there is oil pressure.
1993 Amigo 4wd Hard top, Delta 260, elephant feet, Skyjacker Nitros, 3" suspension lift, Indy4x HD tie rods, Revolution Gears, Maxxis MT-764s 31x10.5x15
Apeiron
Zu Royalty
 
Posts: 1495
Joined: Tue Sep 21, 2010 3:10 am
Location: Santa Ana, San Jose, Costa Rica
Has thanked: 0 time
Have thanks: 54 times

Re: Fuel pump problem...I think

Postby bendorfold » Sat Mar 22, 2014 6:01 pm

captkai wrote:Does anybody know what this little electrical component does? I appears to be connected in parallel with the fuel pump. (see arrow)

Should be a condenser, to control voltage spikes.
"Use it up. Wear it out. Make it do. Or do without." War Advertising Council: May, 1944

"It is better to keep silent and be thought a fool than to speak and remove all doubt." - maxim

mine - 1989 Trooper, 2.6L, 5-spd Manual, 170,742 miles, Stock - SOLD
my son - 1992 Trooper, Auto, DOHC, 225,000 miles (362,102 km), Stock -Still Good
mine - 1996 Trooper, 5-spd Manual, SOHC, 163,849 miles, Aisin Manual Hubs - Totaled
Isuzu mechanic during 1988-1992 Model Years

For this post the author bendorfold was thanked by:
captkai
User avatar
bendorfold
Zu Royalty
 
Posts: 1050
Joined: Sun Jul 02, 2006 4:24 pm
Location: near, but not in, Philadelphia, Pennsylvania USA
Has thanked: 0 time
Have thanks: 11 times

Re: Fuel pump problem...I think

Postby captkai » Sun Aug 03, 2014 1:11 pm

I finally just bought a new fuel pump (a Bosche); and replaced it in early May. I also painted the electrical caps where the wires come out of the Pump Hanger with liquid electrical tape and replaced the electrical connector with a "trailer" 2 wire connection. My car has started every time since.... I hope I am not jinxing myself by posting this. I think the fix was the fuel pump (the new "trailer" connectors were in before the new fuel pump and that didn't fix anything). If it was the electrical tape paint......I will never know because I did the paint and pump at the same time! History-the truck would just choose not too start sometimes; trouble shot for a LONG time....
1990 Extended Cab Isuzu Pickup, 2.6 L 4ZE1; 5 speed 4WD
1994 Isuzu Trooper 3.2 L SOHC automatic
captkai
Drives on Gravel
 
Posts: 48
Joined: Fri Sep 21, 2012 3:29 pm
Has thanked: 32 times
Have thanks: 2 times

Re: Fuel pump problem...I think

Postby bendorfold » Sun Aug 03, 2014 2:02 pm

Glad it's working for you. The 2.6L/5-speed combo are so much fun to drive.
"Use it up. Wear it out. Make it do. Or do without." War Advertising Council: May, 1944

"It is better to keep silent and be thought a fool than to speak and remove all doubt." - maxim

mine - 1989 Trooper, 2.6L, 5-spd Manual, 170,742 miles, Stock - SOLD
my son - 1992 Trooper, Auto, DOHC, 225,000 miles (362,102 km), Stock -Still Good
mine - 1996 Trooper, 5-spd Manual, SOHC, 163,849 miles, Aisin Manual Hubs - Totaled
Isuzu mechanic during 1988-1992 Model Years
User avatar
bendorfold
Zu Royalty
 
Posts: 1050
Joined: Sun Jul 02, 2006 4:24 pm
Location: near, but not in, Philadelphia, Pennsylvania USA
Has thanked: 0 time
Have thanks: 11 times

Re: Fuel pump problem...I think

Postby Nadz » Tue Sep 30, 2014 1:28 am

Hi everyone, I know this is an old post but its relevant to my problem! I have a 1990 Rodeo 2.6L DLX 4ZE1 motor just rebuilt and put back on the road but recently I've experienced problems with the fuel pump. Occasionally on start up it runs for about 4 seconds then sputters and cuts out. When it is working normally the fuel, battery and hand brake lights come up on the dash lights and the air con doesn't work. From gathering information off this post, I decided to check the relays and had the alternator checked. I got new relays and the alternator is fine but I'm still puzzled as to why this problem occurs occasionally. Would appreciate any advice or feed back relating to the issue.

Thanks
Nadz
Drives on Pavement
 
Posts: 1
Joined: Tue Sep 30, 2014 12:59 am
Has thanked: 0 time
Have thanks: 0 time

Re: Fuel pump problem...I think

Postby DSUZU » Sat Jan 03, 2015 8:53 am

bump to the top
1991 LS Trooper 2.8 V6 5 speed conversion (Sold)
1989 LS Spacecab 2.6 5 speed 4x4 manual hubs, Rodeo torsion bars, extended shackles, 2" lift, K&N airfilter (drop in), dump bed conversion, burgundy interior change, warn brush bar.
Previously owned: 1987 Trooper II LS, 1989 Trooper (parts only), 1994 Trooper 3.2 Auto, 1997 Rodeo 2.6 5 speed, 1993 shortbed pickup 2.3 (project - sold) 1992 Rodeo 4x4 LS (parts car, devoured by Spacecab needs) plus some 70 plus other non Isuzu vehicles over the years.

http://forum.planetisuzoo.com/viewtopic.php?f=15&t=64060

The American dream is getting farther and farther away from the American.

If your wife has 5.00, and you have 20.00, your wife has...25.00

"Water is one of the greatest essentials of life. Without water, you can't make coffee."
DSUZU
I am the Stig
 
Posts: 7054
Joined: Fri Mar 16, 2012 8:28 pm
Location: St Pete Florida
Has thanked: 220 times
Have thanks: 626 times

Re: Fuel pump problem...I think

Postby Bjesseg » Sat Jan 03, 2015 9:44 am

I have almost the exact same issue as Nadz. Just rebuilt the engine. New fuel pump. I haven't checked the alternator yet or tried the jumper fix. Going to try that today, need to get it home.
1990 Trooper 2.6l manual
Bjesseg
Drives on Pavement
 
Posts: 18
Joined: Wed Nov 26, 2014 7:38 pm
Has thanked: 1 time
Have thanks: 0 time

Re: Fuel pump problem...I think

Postby captkai » Wed Jan 14, 2015 3:23 pm

" the fuel, battery and hand brake lights come up on the dash lights and the air con doesn't work" Those are the same symptoms I had on a 3.2l 2004 trooper; I didn't get the alternator tested..but I did take the alternator out and replaced it with a new one from Napa. That fixed my trooper. (car would run, but I never took it out. I just charged the battery and started it to see if magically fixed itself for a few days)
I also had an intermittant start problem with my pick up for a long time (some posts in this thread and a lot of PMs) ; I finally changed the fuel pump and problem went away.
Could your alternator be failing; and it was just working well while it was being tested?
1990 Extended Cab Isuzu Pickup, 2.6 L 4ZE1; 5 speed 4WD
1994 Isuzu Trooper 3.2 L SOHC automatic
captkai
Drives on Gravel
 
Posts: 48
Joined: Fri Sep 21, 2012 3:29 pm
Has thanked: 32 times
Have thanks: 2 times

Re: Fuel pump problem...I think

Postby Bullseye » Wed Mar 30, 2016 10:41 pm

Thanks for all the help in this thread. I am about to try jumpering but I have a couple questions first.
88 Trooper II: I have been dealing with a starting problem for months now. I have changed the fuel pump, fuel pump relay, and fuel filter. I had the alternator checked at Advanced Auto. I did not remove it to have it tested, they tested it while running. Historically if I can get it to start it will start the rest of the day with no problem and it runs great. If it doesn't start, it may be hours or a couple days before it will.
Will the alternator test "good" even if it is the problem?
Are their any other pieces of the fuel system I should consider replacing?
Bullseye
Drives on Pavement
 
Posts: 7
Joined: Thu Dec 27, 2012 10:04 pm
Has thanked: 4 times
Have thanks: 1 time

Re: Fuel pump problem...I think

Postby Selahdoor » Thu Mar 31, 2016 12:26 am

Bullseye wrote:Thanks for all the help in this thread. I am about to try jumpering but I have a couple questions first.
88 Trooper II: I have been dealing with a starting problem for months now. I have changed the fuel pump, fuel pump relay, and fuel filter. I had the alternator checked at Advanced Auto. I did not remove it to have it tested, they tested it while running. Historically if I can get it to start it will start the rest of the day with no problem and it runs great. If it doesn't start, it may be hours or a couple days before it will.
Will the alternator test "good" even if it is the problem?
Are their any other pieces of the fuel system I should consider replacing?

Yes, the alternator will "test" good at an auto parts shop, even if it is bad. They do not test the circuit that runs our fuel pump.

Try removing the fuel pump relay, and jumpering in the way I have suggested, which bypasses the relay, and bypasses the alternator circuit, but doesn't leave the fuel pump always powered. (It is only powered when the ignition is turned on.)
-Jeff
1988 Trooper LS. 4ZE1. mua5.

How can I help you or make you laugh today?

For this post the author Selahdoor was thanked by:
Bullseye
User avatar
Selahdoor
Forum Admin
 
Posts: 7271
Joined: Tue Dec 28, 2010 1:42 am
Location: Index, Wa.
Has thanked: 96 times
Have thanks: 165 times

Re: Fuel pump problem...I think

Postby Bullseye » Thu Mar 31, 2016 9:13 pm

I tried jumpering and I could hear the fuel pump running. It cranked but would not start. I must have something else going on. It is a bigger problem because it is intermittent and is getting worse. Any help is greatly appreciated as I am still very much learning.
Bullseye
Drives on Pavement
 
Posts: 7
Joined: Thu Dec 27, 2012 10:04 pm
Has thanked: 4 times
Have thanks: 1 time

Re: Fuel pump problem...I think

Postby DSUZU » Fri Apr 01, 2016 9:23 am

Can you post a picture of your fuel pump relay area? I no longer have a Trooper for comparison, but can offer some trouble shooting ideas. I hav eto compare tests against my 19989 pickup. Dennis
1991 LS Trooper 2.8 V6 5 speed conversion (Sold)
1989 LS Spacecab 2.6 5 speed 4x4 manual hubs, Rodeo torsion bars, extended shackles, 2" lift, K&N airfilter (drop in), dump bed conversion, burgundy interior change, warn brush bar.
Previously owned: 1987 Trooper II LS, 1989 Trooper (parts only), 1994 Trooper 3.2 Auto, 1997 Rodeo 2.6 5 speed, 1993 shortbed pickup 2.3 (project - sold) 1992 Rodeo 4x4 LS (parts car, devoured by Spacecab needs) plus some 70 plus other non Isuzu vehicles over the years.

http://forum.planetisuzoo.com/viewtopic.php?f=15&t=64060

The American dream is getting farther and farther away from the American.

If your wife has 5.00, and you have 20.00, your wife has...25.00

"Water is one of the greatest essentials of life. Without water, you can't make coffee."
DSUZU
I am the Stig
 
Posts: 7054
Joined: Fri Mar 16, 2012 8:28 pm
Location: St Pete Florida
Has thanked: 220 times
Have thanks: 626 times

Previous

Return to Hall of Fame

Who is online

Users browsing this forum: No registered users and 1 guest