Help new engine won't start
Thread Starter
Burning Brakes
Joined: Oct 1999
Posts: 1,236
Likes: 91
From: Pittsburgh,PA
Help new engine won't start
My new 388 will not start it cranks fine has plenty of spark and has 35-40 PSI at the fuel rail. The injectors are not firing. All the connections are good, I've tried different computers and chips, with the key on I get 12 volts at the injectors, timing is set right.
This is on an 85 running vortec heads super ram headers stock distributor.
When I say cranks fine I mean rotates like It's supposed to with no sign of even trying to start no spiting or poping nothing.
Dave
This is on an 85 running vortec heads super ram headers stock distributor.
When I say cranks fine I mean rotates like It's supposed to with no sign of even trying to start no spiting or poping nothing.
Dave
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
The ECM pulses the injectors based on two signals from the distributor. One, the distributor reference pulse (purple/white on my 87) and two, spark timing (white on my 87). You need to check for pulses on these two wires when cranking. No pulses, suspect the pickup coil and/or the spark control module. The spark control module can be removed from the distributor and tested at a parts store and the pickup coil can be checked for resistance. A scan tool can tell you if the reference pulse is being received, or you can see the pulse with an oscilloscope (spark timing pulse too with the scope).
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
Verify that all of the ground wires are attached at the bellhousing stud on the driver side of the trans. I think the stud is the 2nd bolt from the bottom that bolts the transmission bellhousing to the engine.
Ground point G104 is the ground point for the ECM, ESC module, Wiper Motor and a braided ground from the engine to the frame. Maybe some one missed attaching one of these wires.
Ground point G104 is the ground point for the ECM, ESC module, Wiper Motor and a braided ground from the engine to the frame. Maybe some one missed attaching one of these wires.
Thread Starter
Burning Brakes
Joined: Oct 1999
Posts: 1,236
Likes: 91
From: Pittsburgh,PA
Ok up date, I assumed that the injectors were not firing because I had 40 PSI at the fuel rail but no fuel was getting to the cylinders but just to make sure I made up a LED test light to see if the injectors were flashing. Well they are which I beleve means they are working as there supposed to. Correct? So am I also correct in thinking the fuel rails have some kind of blockage?
Dave
Dave
Pro
Joined: Jul 2003
Posts: 543
Likes: 0
From: DFW Texas
I just got my 91 383 fired up today. I started trying at 9:00 this morning. It would turn over and not fire. I pulled the wiper motor to check for all the grounds. Found one loose, fixed it. Still wouldn't fire. Took module out of dist to have it checked. It checked OK. When I began to put the dist back together I found the purple/white wire had been pinched between the cap and dist body. Wrapped it all up and it fired right off about 5:00 this afternoon. Good luck with yours.
Safety Car
Joined: Sep 2003
Posts: 3,599
Likes: 24
From: Orange County NY
St. Jude Donor '10-'11-'12-'13
Some basics:
Make sure the distributor is in properly (at #1 TDC, rotor pointing to #1 cylinder), make sure the plug wires are in correct firing order. Have you tried starting it with the distributor in slightly different positions? Sometimes it is enough to cause a no-start.
What about the valves / rocker arms - are you sure they are adjusted properly? Too tight (past zero lash) and the valve(s) will not be able to seat properly, resulting in no compression in the cylinder.
Make sure the distributor is in properly (at #1 TDC, rotor pointing to #1 cylinder), make sure the plug wires are in correct firing order. Have you tried starting it with the distributor in slightly different positions? Sometimes it is enough to cause a no-start.
What about the valves / rocker arms - are you sure they are adjusted properly? Too tight (past zero lash) and the valve(s) will not be able to seat properly, resulting in no compression in the cylinder.
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Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by opel
Ok up date, I assumed that the injectors were not firing because I had 40 PSI at the fuel rail but no fuel was getting to the cylinders but just to make sure I made up a LED test light to see if the injectors were flashing. Well they are which I beleve means they are working as there supposed to. Correct? So am I also correct in thinking the fuel rails have some kind of blockage?
Dave
Dave
Thread Starter
Burning Brakes
Joined: Oct 1999
Posts: 1,236
Likes: 91
From: Pittsburgh,PA
Hey, I want to thank every one for there input. I think I found the problem but can't work on it till my wife gets up ( we are working midnight this week) I'll let every one know if this fixes it, but I wounder if any one can guess what the problem was.
Dave
Dave
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by opel
Hey, I want to thank every one for there input. I think I found the problem but can't work on it till my wife gets up ( we are working midnight this week) I'll let every one know if this fixes it, but I wounder if any one can guess what the problem was.
Dave
Dave
Timing, Timing, Timing. Got to verify it beyond a shadow of a doubt. Heard this story lots of times after work had been done. Check that #1 cyl !! 
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by opel
Oh close aminnich. I did not leave some thing in but left some thing off.
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Originally Posted by opel
nope
Oops, just reread first post--injectors not firing. On LT1s that could be no oil pressure reading, don't know about the l98 though.
Last edited by aminnich; Apr 11, 2006 at 02:03 PM.
OK for me, tell us, tell us.
Thread Starter
Burning Brakes
Joined: Oct 1999
Posts: 1,236
Likes: 91
From: Pittsburgh,PA
85autoxr, It must be the ghost form your engine, ever since I had your enigne in I've had nothing but trouble.
I found out I had a full tank of water not gas. There was so much water in the tank you could drink it, I did. I went to siphon some gas out to spray in the throttle body just to make sure it would fire if it got fuel. Of course I got a mouth full but what I got was only about 10% gas and 90% water it would not burn even when i took a torch to it. The gasket around the sending unit in the tank was bad and with the car sitting since the middle of last summer it slowly filled up. I've had a helll of a time getting all the water out of the entire fuel system. The tank was easy the lines,runners, and injectors sucked. I ended up taking the super ram back off and pulling the injectors. A firend had a spair set of injectors so I used them and cleaned every thing else out very good. I got it to fire for the first time tonight I only ran it for a second there was still a lot of stuff not hocked up. I hope to drive it tomorrow.
Dave
I found out I had a full tank of water not gas. There was so much water in the tank you could drink it, I did. I went to siphon some gas out to spray in the throttle body just to make sure it would fire if it got fuel. Of course I got a mouth full but what I got was only about 10% gas and 90% water it would not burn even when i took a torch to it. The gasket around the sending unit in the tank was bad and with the car sitting since the middle of last summer it slowly filled up. I've had a helll of a time getting all the water out of the entire fuel system. The tank was easy the lines,runners, and injectors sucked. I ended up taking the super ram back off and pulling the injectors. A firend had a spair set of injectors so I used them and cleaned every thing else out very good. I got it to fire for the first time tonight I only ran it for a second there was still a lot of stuff not hocked up. I hope to drive it tomorrow.
Dave