Hard Starts
- Thread starter mysyclone
- Start date
NorwegianTy
New member
Re: Hard Starts
Just want to trow this out there: you remembered to disconnect the "famous" tan wire when setting the timing after your rebuild? Truck will run if not, but sputters and misbehave. Got the impression that many people forget this when checking/setting timing..
Just want to trow this out there: you remembered to disconnect the "famous" tan wire when setting the timing after your rebuild? Truck will run if not, but sputters and misbehave. Got the impression that many people forget this when checking/setting timing..
Don W.
Stab it and steer it
Re: Hard Starts
Has someone checked the book. Mine's at the shop but, when cranking system voltage is low. Can this lead to a weak spark in our electronic systems. Might be worth a coil swap just to check. Harder to do but worth a shot, swap the ign module. Timing doesn't seem to be the issue because once running doesn't it run OK? I'm thinking gotta be spark or fuel.
Has someone checked the book. Mine's at the shop but, when cranking system voltage is low. Can this lead to a weak spark in our electronic systems. Might be worth a coil swap just to check. Harder to do but worth a shot, swap the ign module. Timing doesn't seem to be the issue because once running doesn't it run OK? I'm thinking gotta be spark or fuel.
Re: Hard Starts
Check, i disconected the tan wire. Something in the back of my mind i try not to think about is a bad/missing ground. that would follow the theroy of a weak starting voltage. The only reason a say this is when the truck sits for a week it will drain the battery. Something must be causing that.
Check, i disconected the tan wire. Something in the back of my mind i try not to think about is a bad/missing ground. that would follow the theroy of a weak starting voltage. The only reason a say this is when the truck sits for a week it will drain the battery. Something must be causing that.
JKsSyclone
Active member
Re: Hard Starts
Have the battery tested at one of the local auto parts stores. It could be a bad cell and not the truck. Clean the cables really good while you're at it.
I keep thinking about the 35 psi. I have at least 40psi at start up. I would definitely replace the fuel pump (and install the racetronix harness) whether it is causing the starting problem or not (I'm betting it's related). I definitely wouldn't think about any WOT runs on that old pump.
Have the battery tested at one of the local auto parts stores. It could be a bad cell and not the truck. Clean the cables really good while you're at it.
I keep thinking about the 35 psi. I have at least 40psi at start up. I would definitely replace the fuel pump (and install the racetronix harness) whether it is causing the starting problem or not (I'm betting it's related). I definitely wouldn't think about any WOT runs on that old pump.
Don W.
Stab it and steer it
Re: Hard Starts
OK, got my book. Ton of stuff to check if it cranks but won't run. I'll try to post the nutshell version.
Key on, check engine light on? Yes
Check for spark while cranking.
Yes?
Check fuel pump runs for 2 secs with key on.
Yes?
Connect inj test tool to cyl 1&2 crank enj. Does light flash on both?
Yes
Check fuel pressure with key on. Should be 35-38 psi
Yes?
Check for fouled plugs or stuck open EGR
ANYBODY MENTIONED STUCK EGR YET?
There is a test for faulty ign module. Can post if you want.
Additional tests to check if injs are firing. LMK if you get that far.
HTH
OK, got my book. Ton of stuff to check if it cranks but won't run. I'll try to post the nutshell version.
Key on, check engine light on? Yes
Check for spark while cranking.
Yes?
Check fuel pump runs for 2 secs with key on.
Yes?
Connect inj test tool to cyl 1&2 crank enj. Does light flash on both?
Yes
Check fuel pressure with key on. Should be 35-38 psi
Yes?
Check for fouled plugs or stuck open EGR
ANYBODY MENTIONED STUCK EGR YET?
There is a test for faulty ign module. Can post if you want.
Additional tests to check if injs are firing. LMK if you get that far.
HTH
Don W.
Stab it and steer it
Re: Hard Starts
Don't forget to check that EGR valve. Easy to get to. The flow chart in the manual for "cranks but won't start" is 2 (two) pages long! See nutshell of page one above. LMK if you need further info.
When it does start what RPM does it jump to? A high RPM would indicate a vac leak somewhere. High, in this case, being over, say, 1200 RPM.
Keep us posted. Curious what this turns out to be.
Don't forget to check that EGR valve. Easy to get to. The flow chart in the manual for "cranks but won't start" is 2 (two) pages long! See nutshell of page one above. LMK if you need further info.
When it does start what RPM does it jump to? A high RPM would indicate a vac leak somewhere. High, in this case, being over, say, 1200 RPM.
Keep us posted. Curious what this turns out to be.