[joes88stang]

i have a 1988 mustang lx 2.3 automatic
it is running rich. it leaves a black spot by the exhaust on the ground. when you first start driving it runs good then after about 8 minutes of doing about 50mph it will ride jerky. if you come to a stop it will idle rough at about 800 rpms and it will put out so much black smoke your eyes will water. replaced o2 sensor map sensor computer, cleaned fuel injectors. egr valve cant figure out. someone suggested a new distributor. im thinking the fuel pressure regulator. any ideas will be a great help

[tripleblack]

Originally Posted by joes88stang

i have a 1988 mustang lx 2.3 automatic
it is running rich. it leaves a black spot by the exhaust on the ground. when you first start driving it runs good then after about 8 minutes of doing about 50mph it will ride jerky. if you come to a stop it will idle rough at about 800 rpms and it will put out so much black smoke your eyes will water. replaced o2 sensor map sensor computer, cleaned fuel injectors. egr valve cant figure out. someone suggested a new distributor. im thinking the fuel pressure regulator. any ideas will be a great help

Hmmm. Could be a lot of things.

First thing I'd do is the usual ture-up troubleshooting.

PCV Valve plugged up (should rattle freely)?

Vacuum leaks particulalry around the manifold or gaskets? (If you don't have a stethoscope, use a piece of vacuum hose held to your ear to search for hissing sounds). With your problems, they should be easy to find.

Air filter.

Fuel pressure (check with mechanical gauge - you might well be right about this being a problem, but it sounds like MORE than one thing is gone haywire). Fuel filter. Hey, when you replaced the fuel injectors, did you stay with the OE size or change the size?

Compression test. (Check all 4 cylinders). If any are a lot lower than the others... Bingo.

Timing. Make sure your timing is set right.

Etc. Tune up stuff like plugs and distributor parts. It really sounds like you're getting a low quality spark. Coil. Wires.

Its a bit of a snipe hunt. I'd sort of go through it starting with the fuel and emissions circuit - then the ignition circuit - then the rest.

Just for giggles, your check engine light IS on, isn't it?

[joes88stang]

there is no pcv valve where there normaly is one. check engine light is not on. i only cleaned the injecters as far as i know they are oem

[tripleblack]

Shoot. I gave the guy who bought my 88 LX the manual with the car. I can't recall exactly where everything was suppossed to be, and there are a LOT of things to check. The smog pump, the various emissions items, all the routing for vacuum hoses, etc.

I'm pretty sure it should have a PCV. How it operates without one (and runs like it does) and doesn't trip the check engine light means nothing - the bulb in the check engine light may be out, lol. I bet if you plug into the OBD port you'll find loads of error codes.

[joes88stang]

it had a diognostic check and no codes came up. the engine wasnt running when it was checked. they said you didnt need to start it.

[93stockerstang]

try the transmision module it could be dumping trans fluid into the burn, and the PVC is on the drivers side of engine down the back.

[CaptainSkyhawk]

I had this same exact problem in my 89 2.3 -- this may not work for everyone, for how I fixed it is I took the vacuum hose that's on the EGR valve, removed it from the valve, stuck a screw in it (so that it blocks the air, I guess), and my richness problem went away.

Please, someone tell me why the hell that worked, because I've never been able to figure it out.

[Aimbot1]

Originally Posted by 93stockerstang

try the transmision module it could be dumping trans fluid into the burn, and the PVC is on the drivers side of engine down the back.

that fixed my black spot but not the fuel consumption problem, was about $75 to replace

[Aimbot1]

Originally Posted by CaptainSkyhawk

I had this same exact problem in my 89 2.3 -- this may not work for everyone, for how I fixed it is I took the vacuum hose that's on the EGR valve, removed it from the valve, stuck a screw in it (so that it blocks the air, I guess), and my richness problem went away.

Please, someone tell me why the hell that worked, because I've never been able to figure it out.

wow if i didnt just spend $100 to replace my EGR i would try that

[spencer87]

Did that seriously work? WOW, thats got to be a .2 cent fix.

[sleeper_inc]

I just made a plastic block off plate on the EGR valve (no EGR previsions on the log header) and I hope it works lmao