Crank/No start issue

[cprice831]

Recent issues were bad/slow acceleration or no power, bucking/bogging, and misfires.

To fix this I have replaced:  MAF, TPS, MAP, EGR, EGR tube, distributor, distributor cap and rotor, and set timing to "0" with scan tool.  Issue was a little better but still present so I replaced wires and plugs, coil and ICM.  Issue got even better but was still present.

During a long drive a few weeks ago, truck began losing power, backfiring and bucking/bogging down, very badly.  Stopped to check it--could not find anything wrong.  Gas was low so filled up tank.  When resuming drive, power was back, no bucking and had good acceleration.  I assumed bad gas, OR spider injector or fuel pump was going bad.   Drove this way for about a week.

 

A week ago, the truck died while I was driving and would not restart.

Checked compression--all cylinders are ~150 psi.

I have replaced the lower intake manifold gasket (due to leak I found), re-torqued to spec.  Replaced the spider injector with the upgraded MFI assembly and torqued to spec.  Re-installed the distributor at TDC, according to spec.  No start.  Replaced the crank position sensor.  Still no start.  

Checked fuel pressure--could not hear pump running. Pressure would immediately go to 55 psi with key in "on" position but then drop to less than 10 psi within 2 seconds.  Removed the fuel pump (found the o-ring on return line eroded and basically gone--assuming this was cause of the pressure drop).  Replaced pump and sending unit assembly.  Still can not hear pump running but pressure goes to about 60 psi with key in "on" position and very slowly drops off after about 3 seconds.  Still no start.

 

Battery is new and fully charged.

Could the new coil have been damaged?

Any advise or direction would be welcome and appreciated.  

 

 

[riverbanks]

Use a spare spark plug,put in wire,lay on manifold,how is spark?cam sensor in distributor shot?

[cprice831]

 it was running before with new dist/cam sensor, so I'm assuming it's good?  no helper to check spark but have been trying to see it from the cab--not a good view.

[riverbanks]

Sorry, missed distributor,crap,so try disconnecting MAF electrical connection,try to start it,if that doesn't work,plug back in and unplug cts and try to start jt

[cprice831]

no go on maf.  CTS?   just video'd spark test at #1 plug--no spark.

[riverbanks]

No spark!do you have 12v at coil + with key on?and cts is coolant temp sensor,basically the choke, from the old days, unplugged, default in pcm is cold out,rich,does help with a lean condition,not yours now

[cprice831]

will check vdc and get back on soon

 

[Supreme Pizza]

If everything is working properly, the fuel pump will run for a few seconds when you turn the ignition on. It automatically shuts the fuel pump off, if it does not detect a crank position sensor signal. 

 

As far as diagnosing the problem, I would strongly suggest that you stop throwing parts at your vehicle. It is counter productive, expensive, and often does not solve the problem. You may inadvertently cause addition problems, making it 10 times more difficult to fix. Even when the original problem is resolved, the new problems keep it from running properly. 

 

You have spent a lot of time and money, but the problem persists. It sounds like it would have been cheaper and easier to have it diagnosed for $100 at a repair shop, then you could just replace the one part that's causing the problem. 

 

Hope this helps. 

[cprice831]

starman8tdcIf you don't have something helpful, please keep comments to yourself.  

Every part I used was needed due to age, deterioration or not working.

 

riverbanks--no 12 at coil.  does this point to the pcm?

[riverbanks]

Need to start looking deeper, fusable link?wire leaving starter, running up back side of motor on passenger side,the power feed to fuses and ignition

[cprice831]

thanks for the direction, river. appreciated

[riverbanks]

Just trying to keep you going,you have a crapola situation,"finding the loose wire",so, inspection of feeds,now to fuses,ecm fuse have 12v,both sides? just got to narrow down the weak point

[riverbanks]

And starman,means well also,we all have seen some stuff,hard to tell how it's gonna end up online,his point,a maybe,fair enough

[Supreme Pizza]

Sorry, I meant no disrespect. I am only trying to help. 

 

Your posting said that you replaced:

 

MAF,

TPS,

MAP,

EGR,

EGR tube,

distributor,

distributor cap

rotor, 

wires

plugs,

coil 

ICM 

lower intake manifold gasket

spider injector

crank position sensor 

pump and sending unit assembly. 

 

You said:   "Every part I used was needed due to age, deterioration or not working"

 

If all of those parts were determined to be defective and due for replacement, then I stand corrected. Sorry if my previous suggestion was out of line. Just trying to help. 

 

Some people throw parts at a vehicle without knowing what to replace in order to solve the problem - sorry if I assumed you were in that category.

 

Its unfortunate that replacing all of those parts did not resolve the problem, but if they were all bad - then it was unavoidable and needed to be done anyway. 

 

The good news is that when you do fix the problem - the truck should run REALLY well with all that new stuff. 

 

[Mikebtte]

Wow, sounds like a tuff issue your having. Have you verified no spark? 

I have had a time where I had a bad ground result in no spark and also had a coolant temp sensor cause a rich condition resulting in no start. You can try disconnecting the coolant sensor on the manifold and see if it starts. Also try disconnecting one injector to see if it starts. This may give you a different result and help your diagnosis.