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1988 2.6 5 spd Rebuild

80K views 596 replies 18 participants last post by  hessmess 
#1 ·
Still have not had time to go through it or start the cleanup. I am sure I will have a million questions. I noticed the fuse box did not have a cover and I know the cover tells what the fuses and relays etc. are for. I have a few empty slots and it may be for stuff this vehicle never had. Manual door locks and windows. Anyone know where I can source this missing cover?

BTW I think this is the original paint, does anyone know what it was? Beige? Yellow?

Thanks
Alan
 

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#377 ·
giusedtobe said:
You know I don't have confidence in any gauge right now Lol but I did try two different ones and they did move when I blew compressed air into them to see if I was crazy or not. I forgot that I T'd into the fuel line where the fuel filter is and got zero pressure there too no more than 3' from the tank. Is there a fuel pump you recommend? I just got one off parts geek or rock auto with no thought as to quality.
When I was doing my research on here it seemed Carter was the highest regarded of the rockauto selection, and to absolutely never get the Airtex one
 
#378 ·
giusedtobe said:
BTW did I mention I found an exact 88 Trooper 2.6 5 speed that I bought for $375?
"If there are no pictures it doesn't count" is a phrase I've heard around this forum over the years... just sayin'. :wink:

I'm psyched to hear that the compression is solid across the board, that's a huge relief! I've read that the injectors are "batch fire" although some references are all four and some are 2x2... if you can't get a definitive answer let me know, I've got a few people I can ask who might know.

As for the fuel pump, there are a lot of guys here who have a lot more knowledge and experience than me, but in my personal experience they seem to be a bit of a crap shoot. I haven't gone beyond the $200 range so perhaps that's the magic break point, but I've had ones close to that much fail in a couple months and the dirt cheap Airtex last for several years. The only thing I've really learned from all of this is the benefit of cutting a "fuel pump hole", dropping the fuel tank when the fuel pump "you're sure will last" fails just plain sucks! LOL!! :lol:

Keep up the great work Alan!!

Jonathan
 
#379 ·
I'll post some pics of number 2 before too long.

So if the ignition is on should I be able to read voltage at the fuel pump? Or is it only present when the engine is turned over?

Did not have a helper so I checked and got zero volts with ignition on. Thinking that maybe I'm getting voltage when it cranks over but maybe less than 12, That or there is an issue in the supply line or vent line.....................or the new pump sucks.
 
#380 ·
It might do to set up your meter so you can see it when you're cranking over the engine. IIRC on these, if you turn the ign to "ON" the pump will run for a few seconds then shut off. So unless you catch that first few seconds on your meter (or test light), you won't see any voltage.

We know with certainty that the fuel pump must run when the engine is cranking, so it would stand to reason that's the best time to check for voltage at the pump.

Maybe with a helper if you can't extend the meter leads far enough to see the meter when turning the ignition.
 
#381 ·
OK so voltage to the pump is good. Fuses and relay are good. The supply line delivers fuel but shows zero pressure.

The only thing I can think of is either the new pump and old pump are both bad, there is some obstruction in the supply line even though I got zero pressure at the fuel filter 2' from the tank, or an injector or more is stuck open pouring fuel when the key is turned over. Now that I think about it this is unlikely because I got zero pressure dead heading the gauge. Trying to think of ways the pressure is released before it registers on the gauge.

Lastly, I managed to get not one but two bad fuel pressure gauges from the auto parts store. Highly unlikely I would think. I think I might try to get some fuel hose and check pressure right off that dang tank.

Stupid question: How much fuel pressure should show just turning it over? Manual says start the engine & check FP. Is this a deal where FP is not developed until it is running?
 
#382 ·
Just to rule out: Can any of these cause a no start?

Throttle position sensor: I checked it per J5's video and it was good
Crank position sensor (as I understand these are in the distributor and I've tried two dizzys)
IACV: Did not test but could this cause a no start or just a idle issue?
Igniter: Got spark so I'm thinking not but assume if you have spark then the igniter is working?
ECM: tried two with no difference.
 
#383 ·
Well, I'd expect it should be pushing somewhere in the range of 40+ psi because that's what the I-TEC system runs at. The FPR controls the ultimate pressure by dumping excess back to the tank via the return line.

Are you SURE you're on the discharge of the pump and not the return line? I checked my old pics of changing the fuel pump on my RS, and the larger line coming out of the fuel pump is definitely the pressure side. The return line, which is closest to the electrical connections, is noticeably smaller.

That's a bummer getting bad test equipment, probably cheap Chinese junk. You could always throw a long hunk of hose on the pump and direct effluent into a container. If it's flowing quite a bit of fuel when it's running, it should be capable of developing pressure as well.

If you've got spark and compression, all at the right times, it should run if it has fuel. Will it light-off with a shot of starting fluid in the intake?
 
#384 ·
I've checked the pressure where the fuel filter goes (new) and dead headed it on the supply line and neither registered on the gauge and yes it was on the supply line.

Was thinking of doing exactly what you are referring to to show flow and also test pressure with a new piece of fuel line.

So many problems and issues I've worked through but if memory serves it did NOT respond to starting fluid & yet I get spark and I've checked timing 100 times.
 
#385 ·
Fuel relay and alternator good? I remember Jerry mentioning the fuel pump will cut off if it detects a bad charging system, seen a few posts about it. Not sure it applies to you 88 though. Just dumping some thoughts here.
 
#386 ·
Covered the fuel pump operating theory on the last page. Alan, Are you hearing the pump run any at all? Dennis
 
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#388 ·
If you've got spark and compression, all at the right times, it should run if it has fuel. Will it light-off with a shot of starting fluid in the intake?

Was my thought Ed. I keep asking myself, why won't it run if the engine has compression, ignition and fuel. I've used starting fluid spray to start many engines that had problems elsewhere that I was later able to diagnose. Wish I was closer as probably many here wish too. I know sometimes 2heads and eyes are better than one. I'll keep following along and I know this engine will run..
 
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#389 ·
DSUZU said:
Covered the fuel pump operating theory on the last page. Alan, Are you hearing the pump run any at all? Dennis
Thanks gents for the replies, so my father in law who is a retired engineer (the kind that can actually fix stuff) took my old Delphi pump and rigged up a test with it in a coffee can of gas. Worked perfectly and I had happened to have just borrowed my third pressure tester I checked it too and it worked great. I was going to run some fuel line off the tank itself to see if I got pressure to rule out the new pump (brand unknown)

When I got home I rigged up my hose and checked and pressure was great so I'm thinking well then it has to be losing pressure somewhere in the line. Thought I'd try it again before doing anything to the line and what do you know, I hook it up and just like that I have 40 psi of pressure at the rail! So I am going to chalk this up to the occasional good luck engine fairy because I didn't do anything to get a different result unless the first two gauges were bad.

So as long as that issue does not return, I'm going to check the injectors with noid lights and then I can put the plenum and TB back on try to get this lump running. Probably be the weekend before I can dig in again but going to recheck all the ignition once I have it back together before trying to start it.

BTW I wish you guys were closer too! Appreciate all the online help believe me.

Island, thanks for the help. The more the better.

Regards,
Alan
 

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#390 ·
islandscrub said:
Fuel relay and alternator good? I remember Jerry mentioning the fuel pump will cut off if it detects a bad charging system, seen a few posts about it. Not sure it applies to you 88 though. Just dumping some thoughts here.
Alternator is new and was charging good when it ran pre-backfire. At this point I'm not ruling out anything but if I understand the function, the engine should start and then shut off if the alt doesn't pick up the power to the FP. Relay seems good and I've tried several to rule that out. Fuses look good. Feeling much better about solving this now that I have the correct fuel pressure.
 
#391 ·
giusedtobe said:
So I am going to chalk this up to the occasional good luck engine fairy because I didn't do anything to get a different result unless the first two gauges were bad.
Alan
I hope the problem was that the first two gauges were bad, sure would be nice to know for sure. Me, I hate it when mechanical things "fix themselves", good luck engine fairy or not. I always have this nagging fear of it happening again when I'm a ways from home. Anyway, glad you appear to have it sorted out.

Mike
 
#392 ·
gruff54 said:
giusedtobe said:
So I am going to chalk this up to the occasional good luck engine fairy because I didn't do anything to get a different result unless the first two gauges were bad.
Alan
I hope the problem was that the first two gauges were bad, sure would be nice to know for sure. Me, I hate it when mechanical things "fix themselves", good luck engine fairy or not. I always have this nagging fear of it happening again when I'm a ways from home. Anyway, glad you appear to have it sorted out.

Mike
Agree, if it is intermittent then I'll get the bad side of the coin at some point. Really just odd but this seems to be a good description for pretty much everything on my Trooper journey.
 
#393 ·
Checked the injector leads with a noid light and they all are pulsing fine. I even checked with the injectors connected to visually confirm a spray of fuel and they looked good so provided the fuel pressure stays as it should then I can rule out compression and now fuel. Going to get it back together and check all the ignition this weekend and see if it will start.

Just to make sure I am doing it right on timing: Crank mark at TDC #4 & 1 and cam mark on the mark on the housing, rotor on #4. I am third and fourth guessing myself at this point. :drunken:

So provided my ignition passes the test it should start.
 
#395 ·
islandscrub said:
yeah. TDC on power #4, TDC on exhaust #1. I've discovered even if the distrib is a tooth off it should start, I had mine one off 'retarded' and it started but ran poorly.
When I first started it I was off by a tooth as well. It ran, not well but it ran. Moved the dizzy back a tooth and it seemed to run great until I drove it and it backfired, Has not run since, other than like crap on 2 cylinders. Still have no idea why it did this.
 
#397 ·
Argh! Darn that brittle stuff. I had to snake the good one from my 2.3L, the one on my 2.6L came broken. Do you have AC? I checked the operation of this thing with boiling water, and it seems only the bottom one (broken one on yours) is the only one that opens and closes via heat. The top one seems to just go straight to the AC fast idle valve and is open when cold. It didnt look like the plunger inside can raise high enough to shut the top opening(s), so I'm not sure why the AC fast idle routes through there at all.
 
#398 ·
Yeah I'm kind of uncertain on what happens if I just cap the whole thing like J5 does in his video. Or maybe somehow plug the lower broken part and keep the pass through air which is totally redundant IMO since it comes off the intake and goes into the I-Tec plenum. It does have an AC system but its been open so its not functional as is. Another project for down the road if I can get this POS running.
 
#399 ·
giusedtobe said:
One step forward and two steps back it seems. Managed to break the plastic thermal valve pulling hoses off and now I've broken my back up!
Those buggers suck, I've collected four over the years but all are broken. I fixed one with a steel sleeve (picture toward the end of my build thread) and have not tested this yet but thinking this this theoretically might work - 15/64" drill hole, 1/4" ID polyethylene tube which eventually get slapped with JB Weld:



Food for thought!

Jonathan
 
#400 ·
shaggydoink said:
giusedtobe said:
One step forward and two steps back it seems. Managed to break the plastic thermal valve pulling hoses off and now I've broken my back up!
Those buggers suck, I've collected four over the years but all are broken. I fixed one with a steel sleeve (picture toward the end of my build thread) and have not tested this yet but thinking this this theoretically might work - 15/64" drill hole, 1/4" ID polyethylene tube which eventually get slapped with JB Weld:



Food for thought!

Jonathan
Nice idea! Thanks. On J5's video he deletes the whole thing. Wondering what I need to do other than plugging the holes to make that work.
 
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