85lebaront2 Posted December 1, 2022 Share Posted December 1, 2022 Don't you have a lift pump in each tank and a high pressure pump at the reservoir on the driver's side frame? Jim, 1990 and up, a high pressure pump unit (called a Fuel Delivery Module) is installed in each tank. Each has two valves, one closes the high pressure line until the pump is running, the other does the same for the return line. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted December 1, 2022 Share Posted December 1, 2022 Jim, 1990 and up, a high pressure pump unit (called a Fuel Delivery Module) is installed in each tank. Each has two valves, one closes the high pressure line until the pump is running, the other does the same for the return line. Okay. I wasn't sure exactly when Ford went to the FDM's. I thought it was after the Aeronose but I get it now that it was the Bricknose/Aeronose transition. The cam chain can be checked for slop by rocking the crank. Pulling the top end down or even a valve cover on these engines is work. I have a pretty good understanding of how the FDM's work. I asked Gary if I could have his dead one to dissect. 🤓 Still... checking fuel pressure is simple. As would be seeing if it hits on a shot of ether while cranking. If Brandon has a noid light he could check to see if the injectors are getting a pulse. (I don't know if the plugs are dry or wet) Link to comment Share on other sites More sharing options...
mat in tn Posted December 2, 2022 Share Posted December 2, 2022 Okay. I wasn't sure exactly when Ford went to the FDM's. I thought it was after the Aeronose but I get it now that it was the Bricknose/Aeronose transition. The cam chain can be checked for slop by rocking the crank. Pulling the top end down or even a valve cover on these engines is work. I have a pretty good understanding of how the FDM's work. I asked Gary if I could have his dead one to dissect. 🤓 Still... checking fuel pressure is simple. As would be seeing if it hits on a shot of ether while cranking. If Brandon has a noid light he could check to see if the injectors are getting a pulse. (I don't know if the plugs are dry or wet) by all means, check the fuel pressure! if the fuel pressure does read lower than spec. 35 psi min running /45 psi static not running. then the fuel filter being stopped up is very common. certainly, start there before condemning any mechanical parts. low fuel delivery will keep the injectors from responding well at all. Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 2, 2022 Share Posted December 2, 2022 by all means, check the fuel pressure! if the fuel pressure does read lower than spec. 35 psi min running /45 psi static not running. then the fuel filter being stopped up is very common. certainly, start there before condemning any mechanical parts. low fuel delivery will keep the injectors from responding well at all. mat, go back and look at his frequency on the MAP sensor and see what that tells you against the table I posted. Link to comment Share on other sites More sharing options...
mat in tn Posted December 2, 2022 Share Posted December 2, 2022 mat, go back and look at his frequency on the MAP sensor and see what that tells you against the table I posted. i may just be tired but i do not see "his frequency" in order to compare. I did wonder about another point though. is the timing which was claimed 9-10 degrees with the spout removed? if not then it seems low Link to comment Share on other sites More sharing options...
mat in tn Posted December 2, 2022 Share Posted December 2, 2022 i may just be tired but i do not see "his frequency" in order to compare. I did wonder about another point though. is the timing which was claimed 9-10 degrees with the spout removed? if not then it seems low also, we are talking about ignition timing yet if the chain has enough play then it will be valve timing too of course. and compensating the ignition does nothing for the valve timing. this is assuming only slack and not jumped time which is an extreme. how many miles are on this chain is a big point. i generally call it on a chain around 150k for slack alone. it's cheap insurance for a mechanic. some may say "life of the engine" is what you should expect from a chain. I just don't take the risk . Link to comment Share on other sites More sharing options...
85lebaront2 Posted December 2, 2022 Share Posted December 2, 2022 i may just be tired but i do not see "his frequency" in order to compare. I did wonder about another point though. is the timing which was claimed 9-10 degrees with the spout removed? if not then it seems low Sorry, He sent that to me on FB, he had a 15-16 Hz frequency at idle which extrapolates to well over 30 in of vacuum. Even in space I don't think that is even possible. On most of the EFI Fords I have worked on, 10° BTDC is static setting with the SPOUT disconnected. 9-10° is close enough to run reasonably. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted December 2, 2022 Share Posted December 2, 2022 Without knowing a thing I replied to Gary's video asking if the truck had good fuel pressure and if the regulator vacuum line was dry. I didn't get the first impression that the cam timing had slipped. I'm not hearing it spitting back, but that may just be because it doesn't have a carb. I hope it's a simple fix! The first post (back in October) does have the symptoms of a clapped out timing set. I came here from the video and didn't see the posts above that. It seems he says 15-16 in/Hg manifold vacuum. Which is not good.... not terrible. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted December 2, 2022 Share Posted December 2, 2022 Sorry, He sent that to me on FB, he had a 15-16 Hz frequency at idle which extrapolates to well over 30 in of vacuum. Even in space I don't think that is even possible. On most of the EFI Fords I have worked on, 10° BTDC is static setting with the SPOUT disconnected. 9-10° is close enough to run reasonably. If Brandon replaced the MAP sensor and is still seeing a reading off the charts low, perhaps he should find a 'shop' with an old school Rotunda tester or just pitch it in the bin? I'd take a scope and feed the pcm what it expects and see if the truck starts and runs. Link to comment Share on other sites More sharing options...
mat in tn Posted December 2, 2022 Share Posted December 2, 2022 The first post (back in October) does have the symptoms of a clapped out timing set. I came here from the video and didn't see the posts above that. It seems he says 15-16 in/Hg manifold vacuum. Which is not good.... not terrible. a fair "old school" test would be to lift off the dist cap with the damper set on 0 tdc and mark the rotor location with a sharpie on the cap base. then see how much play is in the chain from there. all the play that can be found this way is the amount which the ecu is having to deal with also. this seems like a foundational part of the problem solving to me. again, the mileage on this chain can be a major clue. Link to comment Share on other sites More sharing options...
Recommended Posts