Sefi 1.9 car runs rough constantly except acceleration, 1800 hydrocarbons supposed to be 220..plugs wires good, compression good, no vacuum intake leaks apparent after spraying , gas good, fuel pressure 36-40 , no visible cracks in coil

chevy pickup 2wd. (C) gen4 truck, pick up not the Suburban C1500
no engine told and is engine question , no VIN told (has engine code)
4 engine , 3 gas, 1 diesel. gas 4.3,5.0-and 5.7 and D6.5

OK 4.3 told
LOST YOUR SCAN TOOL>? USA answer me, 1998 is OBD2 here.
Barrow ,rent ,buy or get any shop or even car stores to scan it?
that is called misfiring and the can too for sure reports on that,
its not scanning first the reason , we don;'t know./
some car must be driving hard, to get a CEL even 3 times drive cycles. or if in CANADA THEIR Silly OBD2 masks many codes failing , as seen scanned,
a bad FPR can show good fuel pressure then fail up hills or more load put on the engine, (it fails to regulate at all times)
my answers are generic, due top no engine or vin told.
if I had replaced all that, id have stopped
and scanned it, then a compression test now
and make sure all spark plug tips look no, not green with antifreeze or carbon or OIL soaked and then compression test. is really first
no bad engine runs right, for sure below 150psi compression. (gas)
99% of all posts here never tell that engine or scan the PCM./
making answers pure ASE day 1, answer generic.
engine good, ALL CYLspark good , ALLfuelNG good.1,2,3 (pure physics really)
sad is what if EFI OBD2 told you what is failing?
CYLINDER 6 (WEAK COMBUSTION) DTC CODE
say P0306 fails, and spark plug 3 is green COATED (AF50%)
OR SOAKED IN OIL AND COMPRESSION IS 50PSI OR ZERO
SAD TO MISS THAT, NO?
SCAN IT.

check the three basics first .1 is fuel getting to the cylinders . 2 is there spark at plugs . 3 are all air and vacuum pipes,hoses in good condition including the air filter and box , try running with the air intake remove from throttle body , if all these are ok check for cylinder compression , keep me posted if you wish

You have an interference motor. If you had to replace the heads due to the valves possibly touching the motor, you have to consider rechecking the compression after you replaced the heads. I had the same motor that had an intake leak. I found frozen rings on the number 1 piston as well as a bent pushrod. Ultimately, the camshaft had broken due to coolant getting to the bearings. If the spark is good, the fuel is good, then the only other problem you'd have would be compression.

PROBLEM TROUBLE AREA
Rough idle, stalls or
hesitate on acceleration :
.Spark plug faulty
. High-tension cords faulty
Ignition problems:
• Ignition coil
• Igniter
• Distributor
. Incorrect ignition timing
Vacuum leaks:
. PCV valve and line.. .
. EGR line..
. Intake manifold.
• Throttle body
• ISC valve
• Brake booster line

• Throttle body
• Brake booster line
. Incorrect idle speed
. Reset timing
. Adjust valve clearance
. Check fuel system . Check air cleaner
. Incorrect valve clearance
. EFI system problems
. Low compression

First you should try to get codes out of the OBD port with a quality scanner. When was the car last running great and not overheating? What changed first and when? Have you done a cylinder leak test? You could have a blown headgasket.

Possible vacuum leak and or internal engine issue, have a cyl compression check done along with cyl leakage test

If everything you listed is in fact all good, then the only other thing left would be a vacuum leak in the intake runner to #1 cylinder. (intake gasket) It wouldn't be the first time I have seen bad intake gaskets on a Dodge

Hello, This sounds like a cracked or shorted coil. Some of the autoparts stores can check this for you. You can get free scans at Autozone, Advance , or Oreillys. If you have a Vacuum gauge, it will tell you if the Valve springs are floating at higher RPMs.

You can try to water mist the Intake manifold with an old spray detergent bottle. If the RPM changes while the engine is running, you have found a leak which is throwing off all the engine settings.

There were a lot of reports of gas tank leaks and cracking by the fuel tank and fuel pump for this year of Escort. Whether you have this problem may take a Radiator shop to test it. The Emissions hoses could be venting vacuum thru any leaks in the gas tank.

Some of the problems should give you a "Check light", but you should have a free scan to see if your onboard Diagnostic system is even working.

change the plugs and wires.

My problem was solved when I repaired my 4 wd activation dash switch. The switch was contacting on 2WD & 4HI at the same time. The front differential activation is vacuum activated possibly creating a tug of war that didn't actually engage it but drained off vacuum from the engine? A theory at best but stumbbled across it because I knew the switch wasn't working properly I repaired it and low and behold rough idle disappeared and all is good for 3 weeks running.