Scotty you are my only hope…
So, I recently bought my son a 1994 Ford ranger 4.0 manual trans (138k miles) and its quickly becoming a money pit. Upon purchasing, I drove it over an hour at highway speeds…never skipped a beat. I drove it around town without issue multiple times before gifting this to my youngster. As soon as he took ownership it started to fail us. It idles fine and can be revved to 5k without issue, but within a few miles of driving it starts to bog down and stall. Mostly, it seems to occur once the engine is warm. That said, there are times it stalls within a mile or two of driving. I tried to correct this issue by replacing the easy parts… IAC, MAF, TPS, plugs, cleaned throttle body, oil change of course. None of these fixed the issue. So, I brought it to a mechanic. He kept it for weeks and said it has a small head gasket leak that robs the engine of compression once warmed up. While I didn’t notice coolant in the oil, this tracked and I gave him the go ahead to replace the head gasket. He claims to have done just that, including sending the heads to the machinist to be shaved flush. So we got it back and its no better. He had it over a month and I spent nearly $1900 and the issue remains. So I got it back to him. He now claims that there’s in old school trick involving modifying the IAC to reduce air flow restriction and this will definitely fix my issue. He preformed this trick that I cannot find a thing about online and the truck managed to get 10 or so miles but choked down to a stall just before hitting the interstate. I don’t know what to do at this point. I can’t keep throwing money at it but my son needs a car and I’ve WAY over invested in this thing. What do you think? Please use that incredible brain and experience to help one of your oldest subscribers.
Many thanks,
Thomas
He kept it for weeks and said it has a small head gasket leak that robs the engine of compression once warmed up. While I didn’t notice coolant in the oil, this tracked and I gave him the go ahead to replace the head gasket.
It depends on how cracked the head gasket is, and where it's located. If the gasket cracked directly between cylinders, that will not happen. You will just lose compression.
If you were suspecting a head gasket leak, you could have tested the thing yourself without paying $1900. You could have rented a head gasket tester. It comes with blue fluid and it will turn yellow if it detects combustion products in the cooling system. Loading the parts cannon doesn't work, and it will drain your bank account.
Your fuel pump could be starting to wear out. Rent a fuel pressure tester. You can rent them at AutoZone, and it hooks up to a Schrader valve on the fuel rail. It should always read 60 PSI. If it goes below 60 PSI, your fuel pump is weak.
As soon as he took ownership it started to fail us. It idles fine and can be revved to 5k without issue, but within a few miles of driving it starts to bog down and stall.
Have you changed the fuel filter? The filter is external to the fuel tank, below the driver's side door, inside the frame rail.
@justin-shepherd
Thanks for the response. I did have the fuel pressure checked… forgot to mention that… actually 2 separate places have worked on it. The first literally gave up, didn’t charge me a penny, but said they couldn’t figure it out. The current shop is the one that suggested the head gasket and IAC “trick”. They still have it and seem to be committed to figuring it out. I’m just frustrated at how tricky this truck is becoming. It’s absolutely bone stock and doesn’t seem to have been worked on by a shade tree mechanic. I’m just hoping there’s something else out there I can dial in on. Thanks again for the response!
Thomas
I tried to correct this issue by replacing the easy parts… IAC, MAF, TPS, plugs, cleaned throttle body
Did you make sure to only use a genuine Motorcraft IAC and MAF sensor? That truck has OBDI, and you can't go el cheapo on sensors. They must be OE sensors. If it's not generating codes, it's probably fuel pump related.
When my BMW started acting up and tripping the check engine light, I had to press the gas pedal fully down 3x in quick succession to generate stored codes (it was the same age as your truck). I had a problem with my 02 sensors, per the generated code. The CCV valve had gone bad and there was a nasty noise that sounded like a massive rubber chicken. Once I fixed the problem, it took a solid 15 minutes for the check engine light to go out, but I fixed the problem.