Hey people. Thanks for clicking.

I own a 94 EF fairmont tickford LPG.
I bought it with problems and have slowly got there but have yet to figure one out.
Iv searched and searched but don't seem to be able to find the problem.

It wont rev over 3500rpm. Iv read about other problems causing this to happen(eg:speed sensor not connected, map sensor etc) but i have been over every sensor every possible idea. It seems to lean out around 3000rpm. Then at 3500 it seems to be the ecu holding it there. Not like fuel starvation. So im guessing maybe the knock sensor is picking detonation and holding it back maybe?

Checked and replaced items include:
map sensor, tps, air intake temp, crank angle, cam angle, 02, fuel pump,300kpa fuel reg and checked as much of the wiring as possible.

Had to also repair wiring for 02 sensor where the LPG AMS wires are soldered in. Because of the bonnet vents water had entered and corroded them and they had been shorting out. I tried my best to keep lengths the same and made sure the wiring was the same.

The only 2 ideas i have left is that i found when reving was that the idle control solenoid stays open when revving. I believe that's not normal. But im not sure. Is it? Could this be my problem.

The other idea is that it may be injectors. Iv avoided this because of cost and that it doesn't seem like its that kind of problem. I know what injectors are like when they'r stuffed and it just doesn't feel like that at all. Its the computer is holding it back.

Any ideas at all please...

im not an expert so i cant really help but have a read through this http://www.fordmods.com/post1139740.html?hilit=3500%20rpm#p1139740

another guy had the same problem and he fixed it

Last edited by Falcon_92_EB on Wed Jul 08, 2015 10:45 pm, edited 1 time in total.

Thank mate but i also bashed my cat out. I forgot to mention that it has extractors(pacemaker, straight through cat and 2 1/2 inch pipe.

hi thought this might help i had the same problem and it was a stuffed cat converter. the internals of the cat had collapsed ant been pushed through to the next muffler and blocked it up the computer sensed this and prevented the car from reving higher that 3000-3500 i pressume it was to stop engine damage. after i cleaned it out it took bout 10-20 mins of varying driving styles (fast,slow,with ac,without ac,average take off and full throttle take of) for the ecu to relearn itself to run an engine with a clear exhaust flow. after myn had done this i havnt had a prob since and i can rev out in gear the full range of the tacho.
good luck i hope this helps

Thanks mate but iv exhausted all ideas. I had a new rear muffler put on when i did the cat having thought that may happen/happened. Today i replaced all the injectors with ones i knew were good. Checked all wiring. Still no go.

I had the wiring for the o2 fixed up a bit better and thats fixed the computer controlled 3500rpm limiter but its leaning out like crazy around 2300 and up.

Its not a fueling issue. Injectors, fuel pump, fuel reg. lines filters everything has been extensively checked and all mechanicals replaced.

You feel and hear it leaning out. Itl get to about 4000-4200 but wont go past it just sits there. Not missing but sort of spluttering. You notice a big lean spot between 3000-4000 and occasionally will go upto 5000 and seem to be a bit less lean than the 3000-4000 period.

Its not timing. Its all been checked and is fine.

So it must be electrical or something? Do you think something could be in the line maybe. Iv blowin 120psi compressed air through the line with the rail off. My mate was watching and said it was just fuel vapour and definatly did not seem restricted.

PLEASE SOMEONE HELP ME! IM SICK OF SPENDING MONEY!!!!

Atleast i will never have to replace anything in the futuer

Ideas left:
1. Extractors lower o2 reading point not giving ecu correct levels meaning wrong fueling.
2. Other type of wiring/sensor issue
3. ENGINE IS f**k. Im thinking maybe a valve issue i dont know. But theres is an unusual sound of something floating around inside the rocker/block. Its near the inlet manifold second cylinder. I didnt pay to much attention to it. But iv also noticed the oil pressure up really high. I replaced the oil switch but its stil very high. I had originally assumed an aftermarket high flow pump was put in but now im not sure.

I cant see how idea 3 could possibly affect the combustion side of things. But who knows im out of ideas.

Please any one any idea no matter how stupid. THANKS