95 Dekota 3.9- still a mystery
#1
02-18-2012, 04:14 PM
Join Date: Feb 2012
Posts: 5
Likes: 0
Received 0 Likes
on
0 Posts
95 Dekota 3.9- still a mystery
Hi all,
I got a mystery.
95 3.9 automatic dekota stopped working the other week.
The only way to get it to crank is to floor it..and then it shakes, never gets above 1000 rpm, and backfires slightly.
TDC verified - new chain a year ago
Compression OK on all 6 -- 105 or better
Hot Spark - new coil and crank sensor
Fuel pressure checked ok at rail port - 40-45 psi
Fuel relay cuts off after a second on key on, but provides continuous strong fuel flow as the the engine turns over in the cranking process
Spices under PDC check and verified with meter
TPC metered OK- without power - signal not checked
Here's the thing. I think it is flooding. The first time I crank it it starts right for a second and then stops. Won't crank unless I floor it and even then it takes a while...and then runs like mentioned above.
I found there was a mild smell of gas under the hood...and my plugs, while not dripping wet, were wet to the touch and smelled of unburnt gas.
So...now I cranked the engine for the first time until it stopped after a second ....and it would not fire until I pulled the fuel pump relay...and then of course fired only briefly while it dried out the cylinders.
I read a forum entry where someone had similar issues and the problem turned out to be his coolant temp sensor telling the ecm to dump gas like it was racing. I checked mine, and it even fell to pieces when removing it...however the new unit did not change any symptoms for me.
I still believe the fuel injectors are dumping and flooding. Is there anything you can think to check at that level before I replace the computer module?
Also, the fuel pressure guage holds pressure after key-off so I don't think I have any injectors stuck open.
The key crank code shows 12 (power disconnect) 55(end of codes) so no errors there.
I'm one of those stubborn types that can't bring myself to pay dealer book values for repairs on a $1500 truck, but may end up paying more experimenting here.
Thanks for any help in advance.
I got a mystery.
95 3.9 automatic dekota stopped working the other week.
The only way to get it to crank is to floor it..and then it shakes, never gets above 1000 rpm, and backfires slightly.
TDC verified - new chain a year ago
Compression OK on all 6 -- 105 or better
Hot Spark - new coil and crank sensor
Fuel pressure checked ok at rail port - 40-45 psi
Fuel relay cuts off after a second on key on, but provides continuous strong fuel flow as the the engine turns over in the cranking process
Spices under PDC check and verified with meter
TPC metered OK- without power - signal not checked
Here's the thing. I think it is flooding. The first time I crank it it starts right for a second and then stops. Won't crank unless I floor it and even then it takes a while...and then runs like mentioned above.
I found there was a mild smell of gas under the hood...and my plugs, while not dripping wet, were wet to the touch and smelled of unburnt gas.
So...now I cranked the engine for the first time until it stopped after a second ....and it would not fire until I pulled the fuel pump relay...and then of course fired only briefly while it dried out the cylinders.
I read a forum entry where someone had similar issues and the problem turned out to be his coolant temp sensor telling the ecm to dump gas like it was racing. I checked mine, and it even fell to pieces when removing it...however the new unit did not change any symptoms for me.
I still believe the fuel injectors are dumping and flooding. Is there anything you can think to check at that level before I replace the computer module?
Also, the fuel pressure guage holds pressure after key-off so I don't think I have any injectors stuck open.
The key crank code shows 12 (power disconnect) 55(end of codes) so no errors there.
I'm one of those stubborn types that can't bring myself to pay dealer book values for repairs on a $1500 truck, but may end up paying more experimenting here.
Thanks for any help in advance.
#2
02-19-2012, 12:13 AM
Hall Of Fame
Sounds like an ignition/timing problem. Double check the distributor is in the correct position and that all the plug wires are in the correct locations. You said new coil, but how about the cap and rotor and the plugs and wires, did you change those? If you think it is flooding pull the fuel pump relay completely, then crank it over for a while to dry out the intake. Get starting fluid and spray it it while cranking with part throttle. If it starts does it build RPM's?