Post Reply 
 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Isuzu p.up 1988 engine starts then dies
04-20-2013, 06:57 PM
Post: #1
Isuzu p.up 1988 engine starts then dies
Engine starts runs 3 or 4 seconds and off it goes , I would like to know what the problem is? this is my first time at this site thanks'' Oh i changed the fuel pump and checked relay for it and i think its ok'
Find all posts by this user
Quote this message in a reply
04-20-2013, 10:24 PM
Post: #2
RE: Isuzu p.up 1988 engine starts then dies
well first things first we need more info on the size of motor miles transmission size. If my memory serves me right this engine has a carbarator on the engine i would try getting some carb cleaner and spray the heck out of carb to clean it up ... Another problem could be if fuel injected you may have the fuel lines clogged , filter may be clogged, your idle air control sensor may be dirty{iac sensor}. that can be cleaned with some throttle body cleaner and a wire brush.did you change the filter when you changed the fuel pump . i recommend this because the filters easy to change and their usually cheap {somewhere around the 10 dollar price range or less
Find all posts by this user
Quote this message in a reply
04-20-2013, 10:25 PM
Post: #3
RE: Isuzu p.up 1988 engine starts then dies
Hi Mitch,

I think that I would try starting it and then give it a couple of little shots of starting fluid before it stalls. If you can keep it running longer on the starting fluid you will know that the spark is OK and you are loosing fuel. If it is the fuel it may just need a gas filter? If it doesn’t run any longer on the starting fluid you are probably looking for a loss of spark.

Narrow things down for us and let us know what you find so we can give you better advice.

Thanks for using the forum,
Garner

Interested in Mining? Look here: Coal Mining, PA
Visit this user's website Find all posts by this user
Quote this message in a reply
04-21-2013, 12:05 AM
Post: #4
RE: Isuzu p.up 1988 engine starts then dies
Its 2.6 engine and where is that idle sensor ? I will put a fuel pressure gauge on it tommorrow and see what I get. I know the filters not old but I was thinking you could be on to something with ethanol in old lines cloging up things. This fuel injected with a fuel rail. I had noticed when I would take off in the morning I had some power loss lately . That was certainly sign of some sort. Transmission size I dont know. thanks
Find all posts by this user
Quote this message in a reply
04-21-2013, 09:35 AM
Post: #5
RE: Isuzu p.up 1988 engine starts then dies
The power loss could be a sign of many things. As Sandman suggested, the fuel Pump and fuel Filter coexist where a plugged filter can cause pump damage & a damaged pump can plug the filter. So if you change the pump you should change the filter. On the other hand, changing the filter regularly could prevent pump damage by reducing the load on the pump.

Once we know if fuel loss is the problem we can go from there. If you’re going to check with a gauge, make sure that you know what the proper pressures are supposed to be. Different vehicles have different spec.s and even a couple of pounds off can be the problem. If you try the Starting Fluid method, just give it a couple of shots after it starts. If you can keep it running for even several seconds longer you know that there is a fuel problem.

Another thing that comes to mind is a plugged exhaust. If you had a Rotten Egg smell as you were loosing power the problem could be the exhaust. But check the fuel first and get back to us.

Thanks for using the forum,
Garner

Interested in Mining? Look here: Coal Mining, PA
Visit this user's website Find all posts by this user
Quote this message in a reply
04-21-2013, 11:48 AM (This post was last modified: 04-21-2013 11:56 AM by Rupe.)
Post: #6
RE: Isuzu p.up 1988 engine starts then dies
One more thing that is often overlooked is any kind of security system malfunction. Yeah, I know it's an older vehicle but I have spent time pulling my hair out because the security system had an issue and it kept turning the engine off after a few seconds. Usually this kills the spark, which in turn kills the injector pulse. IOW, no fuel AND no spark.

Hint: this may require a helper... put a spark tester on one plug wire and when it quits watch close to see if the spark continues as the engine speed ramps down. If it's still there then you know you are dealing with a fuel issue. Also watch the fuel pressure. If that stays then you know you are looking at injector pulse. If pressure goes away then track down why the pump is shutting down.

Second hint: The fuel pump should run for 2 seconds when the key is turned on. It should also run for 2 seconds after each time the starter operates. That's a sign of the pump and the relay working. If it stops after the engine is running then the signal to "keep going" is not reaching the ECM (ingition or crank sensor) or the ECM itself may be bad. (or as above with a security system issue)

Good luck and keep us posted.
Find all posts by this user
Quote this message in a reply
04-21-2013, 04:30 PM
Post: #7
RE: Isuzu p.up 1988 engine starts then dies
OK guys thanks a milllion. I have narrowed it down- I put my volt tester conected the meter right at the fuel pump and I'M Losing all voltage to fuel pump when I release the key and it will continue running when I hold the key switch very close to engaging the starter so I am losing all voltage upon releasing the key. So that rules out a lot of things. I also opened up ignition key switch up to see if i had some bad contacting situation and bent upward some worn spots sanded those surfaces lightly put it back together with no improvement. We are almost there thanks again!!!!!!!! oh No security system on this truck.
Find all posts by this user
Quote this message in a reply
04-21-2013, 05:01 PM (This post was last modified: 04-21-2013 05:04 PM by Rupe.)
Post: #8
RE: Isuzu p.up 1988 engine starts then dies
For your next step try having a helper pull the small wire from the starter while you hold the key in the crank position ans see if the pump runs. If you can get to it easy enough do the same thing but allow the engine to start. (careful of moving parts) See if it keeps running while holding in crank.

Here's were this may take you.... the car has a fuel pump relay to do one job but many vehicles have a second relay to keep it running once started. (older Nissans as I recall) What happens with age is the relay that stays on full time burns out eventually. In the case of Nissans it was a second set of contacts in the EFI main relay.

If many of your relays look the same check the part numbers on the case, as they may be exactly the same. In this case you might be able to swap say the AC relay in for a test to verify before buying anything.
Find all posts by this user
Quote this message in a reply
04-21-2013, 08:12 PM
Post: #9
RE: Isuzu p.up 1988 engine starts then dies
So I opened switch up on colume cleaned bent a little sanded and when I put it back together I could not turn the starter over - It looks like theres very little tollerance for anything out of perfect alignment, I will get a new switch from Isuzu. So I will check for a second relay like a main relay - I will look but I don't think theres a second relay pertaining to the fuel pump... Shucks I thought I would wrap this up today but to bad..........Hope you guys stay with me on this one so I can brag about u guys.......
Find all posts by this user
Quote this message in a reply
04-22-2013, 12:02 AM
Post: #10
RE: Isuzu p.up 1988 engine starts then dies
Going from memory on the Nipondenso EFI system, but it's almost a direct knock-off of the older Bosch systems. IOW, if the engine cranks that should be the same signal to trip the fuel pump... but only during cranking. The pump should stop about 2 seconds after you release the key unless the engine starts... and that's another signal. Again, going from memory that will be too early for a crank angle sensor so probably an ignition signal to the ECM. Would have to dig up a wiring diagram to go further.
Find all posts by this user
Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)