Hi guys. I don't like to post unless I really can't figure something out on my own and after MONTHS of attempting to resolve the issue I'm finally reaching out.

I have a 2004 with the 4.0 V6 SOHC. 5 speed manual and 4x4. About 1 year ago the truck overheated when I was driving home and had to be towed. I pulled the engine and took it to a reputable shop in my town and they did a complete overhaul; new pistons, rings, bearings, headgaskets, timing etc etc. I got the engine back as a long block and put it back together, then installed it using a Haynes manual for reference. Everything went together smoothly but the truck doesn't start now.

SOMETIMES when I haven't cranked it in a few days and then I try to crank it, it will run for 1-2 seconds and the immediately die. After that it cranks and cranks and cranks with no problem but doesn't fire up. I tried starter fluid thinking maybe it was bad gas or a fuel issue: made no difference. I can hear the fuel pump come on and primed the system 3 times in accordance with the manual I also verified the inertia switch wasn't tripped. Then I verified my spark plug wires were securely on and in the correct order. The plugs are all brand new motorcraft double platinum SP440s that are correctly gapped between 0.062 and 0.068.

I hooked up a timing light to each of the plug wires and cranked it... the light lit up on all of them. Then I connected a Noid light to each of the fuel injector connectors: No light with the key in the ON position, light flashes while cranking. Then I disconnected the MAF sensor and cranked, nothing, same with the IAC. I replaced the crank position sensor and cam position sensor and still nothing. I tried resetting the PCM by disconnecting the battery and waiting 30 minutes but it makes no difference. I don't think compression is the issue as the engine is is a fresh rebuild but I'm probably going to check that as well. I believe that it isn't a fuel issue as the starting fluid made no difference at all to it. But I could be wrong. I'm starting to think I have a timing or electrical issue but have no idea where to start.

Has anyone experienced anything like this or have any suggestions for me? There's probably other things that I tried but forgot to list but I am going to check the fuel pressure now just to finally be able to rule it out. Beyond that I have no idea. Unless the shop didn't set the timing right when they assembled the engine but I did verify the positions of the cams before I put the valve covers on and the slots in the cams did were parallel with the cylinder heads so it looked good. I just didn't have the proper OTC tools to check any further. Thanks in advance!

 

I would test compression on at least 2 cylinders, one on each side, just to take that off the table, expected is 170psi +
Under 120psi means timing has slipped
4.0l SOHC do not use key ways to lock in timing, they use friction fit so can "slip", its rare, but compression test instantly rules that out

Spark plug gap should be 0.052-0.056, never go by the label on emissions sticker, lol, they are always wrong
The spark plugs should have come with that gap
So at over 0.061 you may not be getting spark at the right time or at all in some cylinders

The 50/50 test(spraying fuel into the engine)
And getting a no start means no spark or low compression, period, no other options, so start there

 

So I took your advice and did a compression test and cylinder #1 has no compression. At all. 0. I thought maybe even my gauge was busted so I plug it into my Fairlane and then I got a reading of 150 out of it. So I think you are right. Looks like it jumped time. Tomorrow I will pull the valve covers off to verify but it looks like the shop is to blame. I really appreciate your input. Just goes to show, you can never assume a rebuilt or new engine is going to have compression.

 

Sorry to hear that, but good to find it out

4.0l SOHC engine is an interference engine so pistons CAN hit open valves and bend them, but................that's a worst case scenerio
4.0l OHV engine, used in 1990-2000 Rangers, was non-interference which can cause some confusion

 

Yeah, in a way I'm glad now that at least I know what the issue is. But now it'll be a PITA to get it back out and to the shop and hopefully they won't give me any stink about fixing their mistakes. They told me it had a 1 year warranty but I foolishly didn't ask for it in writing. It's been 2 months since I've got it back, the past 6 weeks of which I have been off and on tinkering with it and troubleshooting to try and find the solution. They may try and tell me that I broke it despite the fact the truck hasn't ran at all in those 2 months. I guess we'll see...

 

You FOR SURE didn't break it
No compression is not an installation issue, if it was a long block rebuild

It's an assembly issue in crank/cam timing which is part of the procedure for all long block assemblies

 

Yeah thats true. Thank you for your feedback. Fingers crossed they remedy it and I have no further issues

 

I just put rebuilt engine in my 2010 XLT. Long story but my final trial was gap in crank position sensor. I installed a new one and found it to have a .015 gap. Had read .040 was standard. Had to drill holes bigger in sensor to achieve this but it started up and ran rough. Drilled holes bigger and elongated with rat tail file and tried .070 gap, ran much better but oscillated at 3K rpm. made holes longer, retarded timing all possible and set at .090 gap and is running great as of today. Hope this helps, I tried quite a few things before running up on this. Hope this helps and good luck.

 

Unfortunately it was as RonD suggested. I did a compression test and my right bank has no compression. So it's a timing issue. I've already spoke to the shop and got it pulled so I'll be taking it there first thing in the morning and they assured me they will fix it