My 1993 Mustang 2.3 daily driver has an oddball problem

93slowpony · 08-01-2008

Ok, so my 1993 mustang LX 2.3l dual plug has a big problem. symptoms are ignition I believe, or throttle position sensor. there is no check engine light either. What happens is that (I have come to the realization its more often when the car warms up) when you put a physical restraint on the cars movement or go up hill, just put a load on the engine the PRMs will only go to about 1700-1900 then drop immediately to 1300-1500 and go back up to 1700-1900 and just keep doing this until you engage the passing gear. when the rpms flux like that black smoke comes from the tail pipe so I do not believe it can be the fuel system.

Replaced when I got the car
All spark plugs
All wires
DIS module
both coil packs
Radiator
fan switch sensor (what ever its really called)
temp sensor
thermostat
exhaust system (not including manifold or o2 sensor)

one last thing, when I accelerate then let off the gas the exhaust starts to make a putter in an non rhythmical pattern. I was informed this may have something to do with the o2 sensor. I do not believe this is a contributing factor, but just in case.

93stangfutr5.0 · 08-01-2008

it sounds like you have the same problem as me it can be your fuel system check the plugs what it sounds like is the system is getting too much fuel. the plugs will be pruty black if it is getting too much fuel mine have maybe 300 miles on them and look like they have 30000 miles on them.

93slowpony · 08-02-2008

turns out there is a ridiculous amount of blow-by so I prolly need to rebuild the engine anyway >_< But A question, does anyone think it could be a messed up valve and after a few times of sputtering the computer compensates the timing to make the effects of a possibly messed up valve seem less apparent?

dreamer1uk · 08-02-2008

Hi,

Did you change the PCV valve yet? Id also do a compression test (wet and dry) to see how bad your rings are then even a cylinder pressure test if you can access the equipment.

If its black smoke, its deffiantely fuel related.

Id test your TPS too with a DMM.

Just out of curiosity, hows your FPR?

93slowpony · 08-03-2008

The FPR is fine. I also had thought to test the TPS but in most cases I have heard of it causes problems at almost all positions not just one specific reoccurring position. I have yet to replace the PCV and I can assure that is a need because its a 150000 mile car and was abused until I obtained it so it has a ridiculous amount of blow by and I doubt it was changed to much. XD Thanks for the responses they have been a great help and any more feed back would be greatly appreciated.

dreamer1uk · 08-03-2008

Hi,

Actually, TPS's can go bad at certain positions, similar to the fuel senders ect. Its still worth it to check it out.

But deffiantely do a wet and dry compression test too. If your 100% sure its blow-by due to worn cylinders, compression rings and oil control rings, your probably looking at a rebuild.

Did you check the valve guide seals?

You could try that engine restore, but i have no clue if it really works.

93slowpony · 08-03-2008

Yeah a rebuild is certainly in order. Gives me a chance to throw some forged pistons a billet rods in it XD..... possibly stroke it and port the head XD then eventually turbo it. But about the problem >_> <_< I want to get it fixed before the rebuild so I don't have to deal with anything once its done. Thanks for the reassurance with the TPS.