What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Help diagnosing, truck stalls

H

Houston_t

Registered Member
Joined
Oct 13, 2013
Posts
53
Reaction score
11
Location
Metro Detroit Area
So a couple weeks ago my truck began running like crap while at a stop light, it was bucking ( kinda like when you try to cut a carbed car off but i wants to keep running ) I got it over a lane then it cut off started it back up and same thing, then it wouldnt start anymore.

After doing some searching here i did a spark test and had no spark so i took the module to get tested and that did the trick. Went on vacation for a week or so got home and let it warm up for 10-15 minutes then went to run errands.

Come out of the store start it up go straight into reverse and it dies after about 5 feet,( now im blocking traffic in Meijer parking lot ) crank it over a few different times and nothing, its sat key forward while i struggled to push it back into the parking spot ( yea no help offered ) get in crank it over and it started but died after maybe 5 seconds ( did this about 4-5 times )

I finally got it started and running for more than 5 seconds so i back out of the parking space and take off but only made it maybe a couple hundred feet before it died again. Started right back up made it another couple hundred feet and then it dies soon as i tune onto the main road. I pull to the side and let it sit for about 5 minutes while i started to type up a for sale ad, tried the key again it started ran perfect the 2 miles back home. i let it sit for a day or so took it out again started right up and ran perfect drove it maybe 5 miles to the store, shopped for about a half hour came out and same problem again.

Where should i start my trouble shooting with this ? Truck is my daily driver so i need her running at her best, money is tight from vacation so i dont wanna just start throwing parts at it.
 
First things first, is it throwing any codes? Codes get stored for 50 start/stop cycles or until the battery is disconnected and can easily be read with a paper clip.
 
No question answer the codes question first. But the next thing I'd do is go to Autozone (assuming you have those) and borrow their fuel pressure tester. You can TRY to fill the tank to full and see if the problem goes away instead of checking fuel pressure and how fast fuel pressure bleeds off after the pump primes the fuel line, but it sounds a lot like your in-tank fuel pump line split, which is a common failure if the line inside the tank hasn't been replaced in some time.
 
dyeager535 said:
No question answer the codes question first. But the next thing I'd do is go to Autozone (assuming you have those) and borrow their fuel pressure tester. You can TRY to fill the tank to full and see if the problem goes away instead of checking fuel pressure and how fast fuel pressure bleeds off after the pump primes the fuel line, but it sounds a lot like your in-tank fuel pump line split, which is a common failure if the line inside the tank hasn't been replaced in some time.
Click to expand...

Tank is full, not looking forward to having to drop a full tank lol.
 
TBIs are simple creatures. Fuel, air, and spark - one of those is off.

Check injector spray with air cleaner off. How does it look? Missing, dripping, or weak?

Have spark? Use a tester if you have one, if not you can ground the plug against your block (don't use your hands). Can you see it spark?

If anyone of those are off, further diagnosis is needed.

Even if your check engine light isn't on right now, codes should still be stored that's your best place to look first.
 
Houston_t said:
Tank is full, not looking forward to having to drop a full tank lol.
Click to expand...
No worries about a full tank. Just disconnect fuel line at the filter and connect a hose off the line coming from the tank into a suitable container (i.e. a Jerry can). Then jumper the fuel pump relay in the engine bay to pump out the gas in the tank. And voilà, empty tank. :waytogo:
 
Speaking of filter, has that been changed recently?
 
People were just commenting in another thread about how the fuel filter is frequently forgotten, I would change it for good measure.
 
Houston_t said:
Yea for the few bucks they cost i will change it out. Thanks
Click to expand...

If you are going to dig into the filter, a good time to check fuel pressure with the test kit. You have to crack the lines somewhere, far better to do it under the truck than at the TBI unit.

As someone else commented, you can also check spray pattern...if the fuel pressure is low enough, you may see something other than a cone shaped spray. But that could also be from plugged injectors, fuel filter, etc. Fuel pressure testing is the best method. No reason to dig into the tank if that isn't the problem.

It sounds near identical to how mine ran when the hose split.
 
can i leave the fuel pressure tester hooked up while i drive ? Problem is it does not seem to do it all the time especially after it sits for a few
 
Houston_t said:
can i leave the fuel pressure tester hooked up while i drive ? Problem is it does not seem to do it all the time especially after it sits for a few
Click to expand...

Just depends on how long hose is from the tester to the gauge. One I borrowed I was just able to get it over the door sill so I could watch it.

Don't really need to drive it to know, if the hose is split, when the ECM primes the fuel system (15 seconds after ignition has been turned off, then turned back to run) you will see fuel pressure immediately drop to zero. My experience has been that if the hose *isn't* split, pressure drops off much slower. Idling can also show fuel pressure issues. If the hose is split, it should be pretty obvious on a fuel pressure gauge. Fuel level, size of hose split, pump efficiency, etc., can all affect how it runs, and why it acts up when it does.
 
tbi used the same flare as the p/s line from late 70's and newer . its the o-ring sealed flare . NOT a double 45* flare like brake and older p/s and fuel used .
 
Often called a saginaw flare. O-ring beneath a flared and flat section of the metal line. No idea why you can't see the pic or the links.
 
You must log in or register to reply here.

Latest Posts

Top Bottom