Help diagnose the Ranger please....

[mustang50lx]

Another possibilty with popping is a bad camshaft. I still think I would look at the distributor personally. Why not take it to a shop you know and have them scope it? You can do a vaccum test to check for a clogged exhaust. In case you don't know how, you hook a vacuum gauge to manifiold vacuum hold the RPM's at 1500 and slowly raise them to 3000. The vacuum should not drop more than an inch or 2. Badly clogged exhust systems will normally drop 6 or more inches of vacuum. This test is normally good. We normally drop the exhaust too if possible. On some cars thats hard to do. Taking the O2 out can subsitute for dropping the exhaust sometimes. When we get clogged exhaust systems at work they are normally not popping. They have a severe lack of power. What is the manifold vacuum reading at idle? Is the needle on the gauge steady?

[stieny]

Another possibilty with popping is a bad camshaft. I still think I would at the distributor personally. Why not take it to a shop you know and have them scope it? You can do a vaccum test to check for a clogged exhaust. In case you don't know how, you hook a vacuum gauge to manifiold vacuum hold the RPM's at 1500 and slowly raise them to 3000. The vacuum should not drop more than an inch or 2. Badly clogged exhust systems will normally drop 6 or more inches of vacuum. This test is normally good. We normally drop the exhaust too if possible. On some cars thats hard to do. Taking the O2 out can subsitute for dropping the exhaust sometimes. When we get clogged exhaust systems at work they are normally not popping. They have a severe lack of power. What is the manifold vacuum reading at idle? Is the needle on the gauge steady?

I don't know if popping is the best way to describe the sound. Maybe it is, I don't know but it almost sounds like a miss that's audible through the exhaust if that makes sense.

I have not taken a read on manifold pressure. I don't have a gauge for that.


I guess I could go have the distributor scoped but like I said before, it was brand new a few years ago. But I guess it is possible for it to go bad again.

[stieny]

Also, if i have a spark problem, I don't see how that equates to getting nearly single digit highway mpg out of a compact 5 speed truck.

Ugh, I should just sell this thing.

[mustang50lx]

Also, if i have a spark problem, I don't see how that equates to getting nearly single digit highway mpg out of a compact 5 speed truck.

Ugh, I should just sell this thing.

If the truck is running bad you have to push the gas pedal harder which could cause lower gas mileage. It's really hard to say without seeing the truck.

[mustang50lx]

A totally trashed O2 could cause bad fuel mileage as could the MAF. Did you check the fuel pressure regulator vacuum hose to see if has fuel in it? If it does the regulator is bad and drawing fuel in through the vacuum line. Cars will run really bad when that happens normally.

[stieny]

Yea, I pulled off the vacuum line and there isn't any fuel in it.

I don't really have to give it any more gas then I used to, or at least it doesn't seem like it. Over the course of that road trip to NYC and back it just started getting awful gas milage and has been ever since.

[somethingclever]

Are you able to check the fuel pressure at the rail?

I would swap out the o2 sensor if the fuel pressure checks out ok.

[stieny]

Are you able to check the fuel pressure at the rail?

I would swap out the o2 sensor if the fuel pressure checks out ok.

I haven't checked fuel pressure only because I don't have a gauge and the pump is brand new. I could rent one though.

[somethingclever]

I haven't checked fuel pressure only because I don't have a gauge and the pump is brand new. I could rent one though.

I want to know if the FPR is good....


The popping may be excess fuel burning in the manifolds....


I would check fuel pressure at rail, TPS voltage, 02 sensor, maf harness for cut wire.

[stieny]

I want to know if the FPR is good....


The popping may be excess fuel burning in the manifolds....


I would check fuel pressure at rail, TPS voltage, 02 sensor, maf harness for cut wire.

Yea, I should probably get a reading at the rails.

But, the popping is in the muffler/exhaust pipping towards the back of the truck. Almost like the engines missing and causing a hiccup in the exhaust. Weird thing is, that I can't always hear it, especially after I drive it for a while but you can hear it more when you first start it and the engine is cold. But the hesitation at light throttle is always there.

[badstanglx]

u mite have a bad injecter too and check see if the egr works are not plug with cause it too

[stieny]

u mite have a bad injecter too and check see if the egr works are not plug with cause it too

I replaced all the injectors with new ones last week. Truck came without EGR.

[pRojekt02GT]

I replaced all the injectors with new ones last week. Truck came without EGR.

Read through all this, fairly odd...

My 93 blazer (4.3) has an EGR issue currently and I have some of the same symptoms you do. Horrible gas mileage, hesitation under slight throttle, rough/poor idle at normal operating temp. Maybe call a dealer, give them the VIN number and check if maybe it did come with an EGR system? Not really sure what to think. Have you maybe sprayed the upper intake to see if you could remove some carbon build up? Try some seafoam as stated earlier, couldn't hurt and its only 8 bucks a can...

Agreeing with the exhaust issue though, that cat could be clogged up some..I know they aren't cheap to replace either. Goodluck with all this!

[stieny]

Read through all this, fairly odd...

My 93 blazer (4.3) has an EGR issue currently and I have some of the same symptoms you do. Horrible gas mileage, hesitation under slight throttle, rough/poor idle at normal operating temp. Maybe call a dealer, give them the VIN number and check if maybe it did come with an EGR system? Not really sure what to think. Have you maybe sprayed the upper intake to see if you could remove some carbon build up? Try some seafoam as stated earlier, couldn't hurt and its only 8 bucks a can...

Agreeing with the exhaust issue though, that cat could be clogged up some..I know they aren't cheap to replace either. Goodluck with all this!

Thanks for the suggestions. I already seafoamed it a few times, the most recent one was a few weeks ago.

I know it didn't come with an EGR from the factory because I was there when my family bought it new in '94. It's been well cared for and landed in my hands three years ago so I know the trucks whole history.

It's weird because sometimes you can't hear anything with it idling and at other times you can. And on this tank of gas, it seems as if it's actually getting ok mileage.

Ugh.....

[2000GT]

How is it running now?