I am having problems getting my 91 F250 running. Engine cranks and has spark, 40 PSI on the fuel rail and does start and run when you feed some gas into the intake. It will kinda try to fire and will run a little if you keep the starter engaged and work the throttle some. Acts like it is not getting any gas. It seems like I have some kind of problem firing the injectors, with 40 PSI on the rail there should be plenty of fuel. Was running fine and just quit and now refuses to start. Was thinking perhaps TPS or some other sensor problem as all of that stuff is original as far as I know.
Yes it could be the TPS or the ECT sensors but also the computer.
Any codes?
Check an injector with a noid light or a neon test light on the non red wire side of an injector and see if it flashes while the engine is cranked.
I havent pulled the codes yet didn't have my reader as truck died 90 miles from home. Am just trying to determine if this will be a field fix or trailer back. What is the likelyhood of the computor just dying? Truck was running ok.
Not as likely as the TFI or PIP sensor in the distributor doing it.
Are you sure you have good spark?
Did you check it with a spark tester?
Rent a noid light from an auto part store to check if the computer is firing the injectors.
They will give you back your money when you take it back.
Am pretty sure the spark is good, it was very visable even in daylight, and the engine did run when manually primed with gas. I think I have an injector test light somewhere from before so will check when I get it home. I was thinking about the sensor in the distributor as well. Am going to trailer it home but need to make sure this old beast is going to be reliable going forward once I get it going agian. I can't complain too much as it has almost all old sensors except O2 with 240 K on the truck. Probably time to just replace them for good measutre.
Ok got back from vacation and pulled codes got 552, 126, 553. By my OBD 1 book code 126 is cylinder identification failure is the only one that would seem to apply. I still dont seem to be firing the injectors as truck will only run with primed with gas.Any ideas on what is most likely cause.
Have a little more information. I checked the injectors with a test light and I get no flashing at all just a solid light that is on as soon as the key is on.
Have a little more information. I checked the injectors with a test light and I get no flashing at all just a solid light that is on as soon as the key is on.
This would be true for one side of all the injectors but the other side should flash.
Cant get to any wiring on that side due to the intake manifold, will keep trying but it's all pretty buried on that side, did jump the EEC relay to rule that out with no effect.
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