Been using the site for some time now. Figured I'd better join and seek real advice.
here goes:
1996 2.3L single cab style side 4x2 standard transmission
Starts easily
Won't idle without throttle
can reach high RPM
Will drive but very difficult have to feather, dies with clutch in at hills, stopping etc. Pop clutch to keep going, very rough and sounds bad
smells of fuel around truck when running

I have done a considerable amount of work.. to this point with no improvement. . New parts, (needed as all were original) plugs/wires, egr, pcm, injectors, fuel filter, fuel pump relay, pcm relay. TPS, air filter, oil/filter change.

Fuel pressure while running 35-40psi
need to checkcompression this weekend when loaner kit gets in.
I am at a loss now. Any help 🙏

 

Check fuel pressure regulator's(FPR) Vacuum hose
If FPR leaks you smell fuel and its sucked in to the engine causing low power and flooding out

Its on the engine, drivers side, FPR looks like a small can, has the Fuel Return hose attached, AND a vacuum hose
Replace FPR if gasoline is in that vacuum hose

2.3l compression should be about 160psi
Under 130psi means timing belt has slipped

Pull out upstream O2 sensor and start engine, it will be LOUD, see if engine runs better, if so you have a Clogged Exhaust, usually collapsed CAT converter
Engine is an "air pump", if "old" air can't get out then new air with fuel can't come in

 

Really appreciate the suggestions. I will check these Saturday morning. Won't have time after work tomorrow. Once checked I'll report back either way.

 

Should I have posted my thread elsewhere on the site? Dont see a way to move it though. If I did my apologies to the other members.

 

Its fine here, a moderator may move it to another sub forum at some point

 

I was able to check the cylinder compression this weekend. This should be fine right?

Front Cylinder = 165 PSI
Second Cylinder = 164 PSI
Third Cylinder = 0 PSI
4th Cylinder = 0 PSI

How I conducted test:

1. Pulled all 4 plugs
2. Pulled Fuel Pump relay
3. Disconnected both coil packs
4. used loaner gauge hand tightened into each cylinder
5. Cranked engine to peak PSI

Pretty sure this isnt going to be a timing issue. Thoughts all?

 

No, not a timing issue
Looks like 3 and 4 have very burnt exhaust valves or a valve is not closing

After you pull off the valve cover you can inspect valve stem height, manually rotate engine to see if there is a cam rocker issue

 

So when running and not moving it has a very "strong" gas odor also.

Ok so pull valve cover and inspect valve stems. when rotating engine what would indicate cam rocker issues?

Also don't think I said. The truck was going doing the interstate when the current situation occurred. It was making power and moving we had noticed a little decline in power but nothing for a truck of this age to cause alarm.

Could a valve spring have broken? Thinking no since both cylinders are dead.

Ron D thanks for staying with me on this.

 

You are looking at the 2 valves in each cylinder(3 and 4) to be opening and closing the same as 1 and 2 valves do
Same height when closed, same depth when opened

While not common the 2.3l intake valves can "tulip", take on a tulip flower shape so no longer seal, the valve stems will often sit up higher than other intake valve stems

You can rotate engine so both valves on say #3 are closed then inject compressed air into spark plug hole, like a Leak down test, but listen at the tail pipe and intake to see which valve is leaking the air
Or the dipstick tube.................hole in piston

Its possible the head gasket between 3 and 4 blew, but 0psi would be a stretch for that, 60-100psi would be expected
0psi is like no valve or piston seal at all

 

Ok understood. I will get the valve cover pulled and inspect and report back progress to the forum.

Question, so is that what they call doing a "Valve job" ? Meaning you inspect and replace just the valves? Does valve replacement require the head to come off?

Thank you

 

Yes, most likely the head will need to come off regardless of what you find under the valve cover unless cam or rockers are the issue, maybe cam broke so 3 and 4 valves are just stuck open

Valve job requires head to come off and then all valves are removed and the valve seats are checked and replaced as needed but all exhaust valve seats are usually just replaced
Valve guides(the part the valve stems slide in) are measured, inspected for wear and fit, replaced as needed
New seats are install and new exhaust valves usually, and these are ground/lapped to match angles to get best seal when closed
Same for intake valves

The parts are not expensive, its the labor
You can get a "rebuilt head" which pretty much means its had a valve job, and you send in your head(core charge) they rebuild it and sell it to the next guy
Or you can take your head to a Machine shop for a valve job, same thing just takes longer, but will be cheaper
Generally 4cyl, 8 valve head would be $500-$700 depending on parts needed and labor rates in your area, for a valve job

 

Ok then. Thank you sir for the feedback. Not a shade tree mechanic job it doesn't sound like.

I will get this checked and if the case I'll start shopping. Thank you again

 

I finally got a little time to pull valve cover. Couple things the bolts on exhaust side were loose. It does have a rubber gasket.
no visual signs of issues. I then rotated everything by hand. I did not note any issues. Everything appeared to move similarly.

At this point I need to pull the plugs and apply air??

Thanks

 

You can do a leak down test, and listen at the tail pipe, intake and oil drain holes(if valve cover is off), other wise dipstick tube
That will tell you where the most air is leaking out of that cylinder, exhaust valve, intake valve or piston/rings

 

Any chance it could be a blown head gasket since two side by side valves lost compression (0) at the same time while driving?

 

Sure, adjacent cylinders both with low compression can be a blown head gasket between the two cylinders, but usually would still show some compression, not 0psi, possible of course, but the gap between the cylinders is pretty small to transfer all the compression out
On the other hand 3 and 4 are on reverse cycles, 3 piston is going up while 4 is going down, so could be sucking out air faster than it being compressed, but thats a stretch

 

Ok will try and get the test done tomorrow. Thank you.

 

Rondd something just occurred to me when I did the compression test I only removed the 4 plugs on the exhaust side I did not remove the ones on the intake side.
Now that I'm getting ready to do the similarsieak down test well they're looped down test I need to remove all 8 spark plugs correct? Would leaving the other 4 in when I did the compression test have impacted the 0 reading on the back 2 cylinders?

 

The other 4 spark plugs stay in, they are just "plugs" in these types of tests to prevent air loss

You did the compression test correctly, exhaust side spark plugs are easier to access and you should remove all 4 when doing compression test to get best starter motor cranking speed, and so the testing is equal across all 4 cylinders

 

I did not have the right tester for leak down and my O'Reilly's was going to have to order. So given I knew whatever the issue at this point I would need to remove the head. So yesterday I pulled the head.
All looked good except the large burned out spot in the head gasket between cylinder 3-4. So it seems it would not build pressure due to air moving between the two cylinders.

I will of course get a new gasket. Additionally have you heard of people putting water in the ports and seeing if the valve leaks when closed? Should I do this and lap the them if leaking?

Here are some photos.

 

Here is a picture of the 4 cylinders. I do not see any vertical scratches or grooves. As someone who has not removed a cylinder head or tore into an engine I am not qualified to say if this looks ok or not but nothing jumped out at me as being overly bad.

 

Yes indeed, that would be a good reason for the 0psi, haven't seen one burned that wide before

Yes, leave spark plugs in and stand the head up so valves are facing up
Fill each cylinder cavity with water
Wait
Then have a look at the intake and exhaust ports on the sides of the head for water leaking out, would indicate a poor valve to seat seal

 

I will do that test then. Thank you and I will report back later.

 

Any suggestion what is a good gasket for the 2.3L?

 

Don't have a 2.3l but I have used Fel-pro gaskets over the years, and have no complaints