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Ocasional hard to start


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Old 07-16-2008, 08:04 PM   #1
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Ocasional hard to start

Hello, please forgive me if this is a newb question, I havent been in here long.


I have a 92 2.5, 5 speed, 2wd, no power nothin', short box. I think I may be fighting a couple of different problems, but Im not sure.

This morning, and one moring a week ago, I was trying to start my truck to go to work, and it would just crank and crank. No fire... I tried opening the throttle all the way but it made no change. The one thing I did notice was that some times it would hit a couple times once I had let off of the start switch, but before the engine had stopped turning. This morning when it did finally start, it hadnt hit untill I had let off of the start switch, then it took off.


I am wondering if I am facing a fuel pump issue, or a power supply to the fuel pump type issue? Possibly a spark issue related to the ignition switch some how?


Possibly a seperate problem...


A few weeks ago, I did some work to my truck. Most importantly, I went through the distributor, cleaned it out, and re-wd-40'd the inside of the cap. Prior to doing that, I had an issue where on really humid days, it would start a little hard, but not as bad as I posted above, then once running, if you were at lower rpms, you could barely give it any throttle or it would act as if it were missing on 2 cylinders. It would do this untill the engine reached full temp, and then it was fine after that.

This problem I am believing to be a spark/moisture issue...

This problem was still there after I had worked on the distributor, but was not as bad. I dont believe that these two problems have much to do with each other, but I may be wrong. I am very green with diagnosis on automotive EFI. I am a powersports mechanic.



Any ideas are appreciated, I have to take this thing on an 16 hour road trip next week
Old 07-16-2008, 11:12 PM   #2
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Re: Ocasional hard to start

Have you replaced cap, rotor, plugs, wires? Check the pickup coil and stator in the distributor and clean. Check the connections on the ignition module, make sure it is not a fuel issue, the Fuel pressure to the TBI unit should be around 14 PSI, does the injector spray into the TBI? will it fire right up on starting fluid/ carb cleaner? Hows the battery holding up? How about the wiring off the battery- cables tight/ clean? Hows the current draw off the starter - is it excessive (I am thinking about maybe a weak battery and lower voltage to the electronics here due to a high load starter.)
Old 07-17-2008, 01:20 PM   #3
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Re: Ocasional hard to start

Quote: Originally Posted by lesterl
Have you replaced cap, rotor, plugs, wires? Check the pickup coil and stator in the distributor and clean. Check the connections on the ignition module, make sure it is not a fuel issue, the Fuel pressure to the TBI unit should be around 14 PSI, does the injector spray into the TBI? will it fire right up on starting fluid/ carb cleaner? Hows the battery holding up? How about the wiring off the battery- cables tight/ clean? Hows the current draw off the starter - is it excessive (I am thinking about maybe a weak battery and lower voltage to the electronics here due to a high load starter.)

The cap, rotor, wires, and spark plugs are not very old and appeared to be in good shape a couple weeks ago. I didnt have anyone around to help me to see if it was spraying fuel or not. The bad thing about it is it only does it once in a while so I cant really do much testing with the problem.

The battery is brand new and so is the starter. It cranks quite fast so Im sure there are no issues that involve those.

14psi is much lower than I expected. There is no shrader valve correct? Im guessing I need to fabricate some sort of in-line gauge to test this?



Where is the fuel pump solinoid locatated? I am kind of wanting to check it out and do some manual wiring to see if I can find an issue there...
Old 07-17-2008, 01:46 PM   #4
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Re: Ocasional hard to start

The relay for the fuel pump is just above the brake booster on the fire wall....(engine compartment) there are two relays and we hot wired mine there... you are looking for the tan wire w/ white stripe...we just unhooked the fuel filter @ the bottom and put a hose on the line coming from the tank so we could pump it off into a gas can.... Hope this helps

Last edited by puppy power : 07-17-2008 at 01:48 PM.
Old 07-17-2008, 06:12 PM   #5
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Re: Ocasional hard to start

Thanks for the tip Puppy Power...



Update...

Today we got hit with a healthy thunderstorm and a down pour over the lunch hour. It had stormed overnight also...

In the morning, it cranked forever before starting like stated before, and once going I had to keep it revved or I couldnt give it much throttle. It would pretty much just die out otherwise...

--At lunch time it down poured hard while I was eating lunch. I had to go down a lightly flooded street on my way back to work. As soon as I hit water, it died out and wouldnt start. About 10 minutes went by and a friend came by with a tow strap. We pulled it down the street and i dropped it in 4th. It fired right up.



I am thinking I am having an issue with either the distributor or the coil, but I havent had any time to deal with it yet.
Old 07-17-2008, 08:55 PM   #6
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Re: Ocasional hard to start

Sounds like Ignition, look over everything real close, make sure the cap is down tight.
Old 07-17-2008, 10:10 PM   #7
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Re: Ocasional hard to start

I got it...


I was spraying water on the ignition system after work, and as soon as I shot water at the ignition coil it died.

I went to Napa and they had a MSD coil sitting there on the shelf that fit it so I bought that. It idles smoother and everything.

Thanks
Old 07-17-2008, 10:46 PM   #8
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Re: Ocasional hard to start

AWESOME! Thanks for posting back! :-)
Old 07-18-2008, 12:31 AM   #9
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Re: Ocasional hard to start

Quote: Originally Posted by lesterl
AWESOME! Thanks for posting back! :-)

Anytime, thanks for the helpfull suggestions...


I am a moderator at suzukicentral.com, so I am all about followup in threads. My main hobbies are dirt toys and my s-10 is my toy hauler/daily driver. I just cant afford to drive the 69 3/4 ton with a beefed up small block and 4.56:1 gears around anymore


Im approaching 180K miles, how long do these things live? Im not sure if this engine has had a timing gear change either. Its not very noisy, but I think its noisier than it was when I got it.
Old 07-18-2008, 09:32 PM   #10
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Re: Ocasional hard to start

They can last a very long time it taken proper care of, the supplier my dad has at school had an astro with over 1M miles on it (not all original, but was close.)
Old 07-27-2008, 11:46 PM   #11
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Re: Ocasional hard to start

i have a 1991 s10 no power anything 2.5 and i will drive it and starts ok but takes some time for it to kick on. Then out of the blue it wont start so i leave it for a day and it starts back up like usual. the fuel pump is working. its getting spark and gas. any ideas on whats wrong?
Old 07-28-2008, 12:25 PM   #12
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Lightbulb Re: Ocasional hard to start

Quote: Originally Posted by josh1991ironduke
i have a 1991 s10 no power anything 2.5 and i will drive it and starts ok but takes some time for it to kick on. Then out of the blue it wont start so i leave it for a day and it starts back up like usual. the fuel pump is working. its getting spark and gas. any ideas on whats wrong?
Josh--

The fuel pump will run long enough to pressurize the fuel rail during start-up cranking, but then shuts off. (This throws a lot of troubleshooters off)..Then, when the oil pressure switch "sees" 4 PSI of oil pressure OR the fuel pump relay kicks in, the fuel pump runs. Usually, this happens instantly and you'd never know that all these things were happening. I got my 2.5 Duke to start quicker by installing a new fuel pump relay. Before, it would "wait" for the oil pressure build-up THEN fire off the pump. Now, with a new relay, it'll start first or second piston up, every time...so, first, on key to start, the pump runs, then shuts off, relay pulls on the pump, if relay is shot, oil pressure switch contacts close at 4 PSI and that brings on the pump, it is a failsafe...

Last edited by Steady Eddie : 07-28-2008 at 12:32 PM.
Old 07-28-2008, 12:57 PM   #13
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Re: Ocasional hard to start

thanks for the information. I was also wondering could it be the coil pack ???
Old 07-28-2008, 10:41 PM   #14
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Lightbulb Re: Ocasional hard to start

josh--

Yes, it could be a weak coil, along with about a million other things, too. The coil can be removed and tested, maybe at a place like Autozone. But to just replace it, is not smart. It is 50 bucks or so to buy, and what if the old one is not bad?? You'd be out the money for nothing--and still have the problem.

For example a weak battery, with a bad cell, will produce just the things you have said. The electronics need about 10.5 volts to work. Or a not-yet-dead module...do the cheap-fix stuff first.
Old 07-28-2008, 10:53 PM   #15
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Re: Ocasional hard to start

ok thanks for the help. what are some of the cheap fixes that i can do?
Old 07-29-2008, 12:20 AM   #16
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Lightbulb Re: Ocasional hard to start..cheap fixes...

josh--

The best cheap fix is for you to buy a Shop Manual...my S-10 came with one and it has proven to be a blessing. Not everything you always wanted to know about the Iron Duke is in there, but it is close.

The sensors can be tested for free, starter can be tested for free, the battery can be load tested for free, etc...

Last edited by Steady Eddie : 07-29-2008 at 12:23 AM.
Old 07-29-2008, 07:49 AM   #17
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Re: Ocasional hard to start

oh ok. well my battery is good. alternator brand new. the thing that bothers me is i have no inner wheel wells and i think the water splashing up on my wiring is taking its toll. Also when i bought the truck all emissions stuff is gone and for some reason the wiring to the starter has been altered. But once you start the ol iron duke it runs good except for the lifter tick
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