ton van der sluijs

Hi there;
I di bought my F150 1994 recently. The guy who sold it to me told not to connect the TPS, otherwise the truck would run strange. I installed a new TPS and today after some investigation with a stroboscopelight I discovered that with the TPS not connected the advanced timing was following the revolutions correctly; in the connected case the timing is jumping back and forth. The engine is a V8EFI 5,8liter and it runs on LPG Does anyone having an idea what the problem is?

greetzz Ton van der Sluijs

ton van der sluijs

Good morning y'all
Nobody seems to have an answer here Probably because there is less or no LPG in the States.
Yesterday a garageman told me that my camshaft position sensor is the bad guy in this story. The PCM gets his info from the ignition itself and from the CPS... what do you guys think about this?

greetzzz Ton

Oldrusty

Repost your questions in the 87-96 section,someone should be able to help you.

I don't think your 5.8 has a cam position sensor. Have you pulled any codes? If not there is a sticky thread at the top of the 87-96 section,
let the PCM/ECM tell you whats happening to your engine.

ton van der sluijs

Goodmorning Old Rusty
Thanks for given me a reply. Here in The Netherlands are so few people who kdo have the knowledge of American trucks, I mean, a lots of salesman, lesser people who can really repair them and specific troubleshooting a few.

The only thing I discovered is, that the ignition is equipped with so called "Hall effect sensor" and that it has no vacuum or advance system; everything happens in the PCM.
You're right; I have to go to the USA car garage, not far from here; he is a wizzard. He dicovered that the harsh shifts did came out of the broken TPS..
The tranny shifts okay now, but now is the ignition the bad omen. Next week I'm going to test the PCM.
I keep you posted

greetzzz Ton

ton van der sluijs

Goodmorning y'all
I.ve heard the solution for my fluctuating ignitiontiming. A Lambdasimulator.
this device shall mislead the PCM in a manner that he thinks he's running on gasoline. Now at this moment the whole gasoline system is out of duty ...that means, that the pcm sees that the prime pump is out of order but the engine is running?!?!?!
I keep you posted

greetzzz Ton

ton van der sluijs

Hello everybody. My ignition is okay now. I did had the wrong LPG stuff. an ordinairy Impco300 was the disturber.... Because I do have an V8EFI, the LPG had to be also an injection operated one.. 1500 Euro's further and and nice following ignitiontiming.

greetings from amsterdam Ton

Good old Bill

Just caught this post, glad you have the timming issue resolved, most people don't follow up with their original threads. Good going ton. Have a question, what is a Lambdasimulator? Its hard to pronounce let alone spell, spending the 1500 Euro, doesn't sound easy either.

ton van der sluijs

Heyy Bill Good to talk with you.
When the first American cars and truck were equipped with LPG, due to a high gasprice, the "old americans, those without sensors, there were no problems. A big Impco 300 , and your car was in love with LPG.. When the first Americans with CO2 sensors, what we name overhere "the Lambda sensor" got their LPG stuff, a lot of troubles arose... Burned valves, bad running, ignition problems. The LPG industry did have a big big problem!! They came with a solution; a simulator which was telling the computer that the info, which came from the CO2 sensor thru the simulator that the engine was running on gas!
For some time it did work, and then came the EFI and MFI engines..... The Lambasimulator did not work at all!! Engines blew up, trannies out of order, because the simulated info disturbed the whole system! Then came Prins (a Dutch LPG equipper) with THE solution; LPG injection, attached to a LPG computer, which converts the info to gas info to the computer. It operates a little bit like the "monkey box" the simu, but now the PCM can inject the LPG as gasoline.
(it's funny that you Americans name gas "Gasoline"; here is the name for dieselfuel "Gasolie"

A long explain, but I think it makes a lot clear for you Bill!

Greetings and tulips from Amsterdam

Good old Bill

Hi Ton, thanks for the education, will have to read it a few times to fully understand it, I have no experience with the LPG stuff. Are the injectors injectors different? I would think so do to the different fuel pressures involved.

ton van der sluijs

Hi Bill
The fuel injectors are blowing straight at the inletvalves.. LPG nozzles are connected with 6 inches hoses and blowing into the base of the upper manifold. Fuel is wet.. LPG is vapour allready.


On the left the round housing is were the LPG is heated by the coolant. Onmthe right attached the electric stopcock.. there come the LPG from the tank. the others are the computer which communicates with the PCM.






greetings to you on