Hello all, seeking some thoughts or advice from done who may have had or know about this issue. Basically my 98 started acting up about two years ago with its starting. Ive generally had to hold the key while it tries to start and then two or three more times before it would finally start. My son showed me the way he has to start his dodge truck by turning the key three times to acc to prime the pump which I've tried and it does seem to start wayyy better on the first turn. A kinda longer than usual turn but definitely way better. Over the past year every now and then on a slow roll take off after putting it in drive itll stall out at about 5mph. It seems that in the past few days its happened a lot more. 3 times each day for the past three days and once so far today.
The fuel pump is only a year old. Ive changed all the basics under the hood. It feels like a fuel issue when it stalls. Pump issue or injector issue or maybe even both?
I was hoping someone here might know from prior experience what the issue most probably is or have any advice to point me in the right direction.
Thanks and I love the forum you guys got going here everyone seems Extremly friendly.

Thanks, veritas

 

Check ball valve is topically the culprit of the long cranking to start. If you got a cheap pump they are known to fail quickly

 

Welcome to CF!

What engine and vehicle are we talking about? I know it's a 98 but what?

The best place to start is to check your fuel pressure, before you try to start it, during it's running, and after shutdown. You can usually rent a gauge for this. If you have an Autozone or Advance Auto near you, try there. Without a gauge, try checking the shraeder valve in the fuel rail first thing in the morning before you try to start it. That's a tire-like valve with a cap on it. Careful, fuel should spray out of it if it's holding pressure overnight. I kinda feel it's not.

 

98 Cherokee 4.0 liter

 

I just tested the fuel pressure and this is the basic breakdown. From the key off position to switched acc it would show 5psi each and every time I tried it. Once the vehicle started and was running it would fluctuate between 29psi/30psi. Does that sound like anywhere near normal behavior. Whatever it is seems to be getting worse because now it's killed twice while running at 45mph down the highway.

 

Okay, according to specs, your fuel pressure running should be 44-54 psi. The fuel pump runs of a couple of seconds when you turn on the key TO IGNITION, not accessory, to prime the fuel rail. When I say, IGNITION, I mean when all the dash warning lights come on. If you're only holding 5 psi overnight, that's okay, as long as it jumps to 50 when the pump primes.

I'm thinking there is something wrong with the fuel pressure regulator. That's mounted on top of the fuel pump at the tank. If you have low fuel pressure, it can't keep up with fuel demand on acceleration and the PCM is shutting down the engine. Unfortunately, the filter is inside the tank, so if that's clogged, you'll have to drop the tank, AGAIN. When the pump was changed, was the tank cleaned out? It's possible there is debris in the tank that's clogged the filter. This is a possible reason the pump failed the first time.

Try cycling the key several times ON IGNITION before trying to start. If you're getting 50 psi after priming but only 20 psi running, I'd say the filter is clogged.