Timing issue? Vapor lock?

[claw32]

I have a 99 ranger xlt. I have had it for about 8months now and about a month ago it started having a problem.
What it does is: after being completely warmed up and driven for a good 15 miles i get off the highway and at a stop sign or red light the engine will begin to stall out, never completely stalled out but acts as if its not getting fuel. When this happens the temp will shoot up, but a minute with the heater on fixes it and the temp will be fine until it happens again. If i hold down the accelerator at a higher rpm stopped then it will try to do this but won't be able to stall out as much, the other day i started out at a light just fine and it did it in the middle of the intersection, when i pushed down on the accelerator nothing happened, when i took my foot off it picked itself back up. Also, when going uphill or having a heavy load in the bed i hear a bunch a crackling from the engine that sounds like preignition, but i have no check engine light, no codes are coming up, the shop i go to wants $900 to do the fuel pump even though one was put in right before i bought it. They replaced to Air Idle Control thinking that was it, but apparently not. It never did this until it started getting 100 degrees outside. Hope someone can help because this is just soooooo irritating

 

[wr250rdr]

Try the fuel filter, a pretty easy change, should be located on the drivers side frame rail. Also if your hearing detonation try running a higher octane gas for a tank an see if you still hear it.
And just as an FYI, efi systems will not vapor lock. It defies physics.

IMO it sounds like a clogged fuel filter so start there and report back

 

[claw32]

Forgot to put that in original post, I did change the fuel filter two weeks ago, no difference, also ran sea foam through the tank, and had engine decarbonized, nothing has made a difference.

 

[claw32]

Also, fuel pressure is fine, it drops when going uphill, but never out of spec. Just changed spark plugs and got spark. Checked coil and its fine.

 

[claw32]

Still no suggestions? darn, little update though, its cooled down to about 90 degrees with a good bit of humidity, and it hasn't done it since the temperature dropped.

 

[nine-teen91stxranger]

air filter durty?

 

[claw32]

No, cleaned it and MAF and connectors

 

[wr250rdr]

Do you still have your cat in your truck? My old s10 had a similar problem and it turned out the cat was clogged and toast. has the problem been getting worse? In my s10 it started as a gradual power loss then it turned into no power at all.

The check is a pain or can damage the cat. If you have access you can put a through pipe in and see if it fixes your issue. Or if you don't have to worry about smog. Take a b.a.h. And hit the cat a few times at each end and in the middle. This will shift things around for a while. Drive around and see if your problem is fixed. If it is it's a bad cat if not square one again

 

[claw32]

yes, i thought about that but thought it would throw a engine light, the stuttering has gotten a little better due to the temperature lowering outside, but still occasionally does it, and have notice a pretty good power loss recently. Still got to worry about smog, anybody have experience with a universal cat? like a magna flow universal? i can find some for about $60 but don't want to waste the money if they're not going to work.

 

[wr250rdr]

It didn't throw a code in my s10. There really isn't a code for a bad cat. The o2 sensors will occasionally throw a code if conditions are right and it throws off their readings, but think about it the rear sensor( which idk if you have, my trick is a 94 and lacks one) is set to measure high levels, less exhaust won't trip it, and the up stream sensor is designed to catch low levels indicating a problem.

Do you have access to a laser temp reader? If you do get your truck good and hot and I mean like 40 minutes of driving hot and take a reading at the front, mid and rear of the cat. You should see roughly 1200 degrees across it if you see a very hot spot it's a clog or if you see a cold spot at the end it's a clog.

As for the universal cats it depends on how much of a dick your smog tech is. When I had my miata I had a high flow cat that he failed me for on the visual because it wasn't oem and it was an altered exhaust. I took it to another shop and they passed me and it passed the sniffer. It also depends on your state and it's smog laws. Here in ca with the Eco-nazis the laws are very strict. Your states might not be