Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

hard starting to no starting- what to do about codes?


HVAC Man's Avatar
Visiting Guest

Posts: n/a

05-20-03, 05:34 PM   #1  
HVAC Man
hard starting to no starting- what to do about codes?

Vehicle: 1991 GMC Sierra 1500 5-spd 2wd 4.3 liter V-6, 165K miles, but does not look it at all!, I have a company vehicle so this truck is only driven a little during the week, and alot on the weekends. a few months ago the truck would have to crank for 5-7 seconds at a time, for a few times, before it would start, it was intermittant, seemed like if truck sat a while would start fine, I thought it was getting flooded (it is an EFI), so I went ahead and changed the plugs, O2 sensor, fuel filter, air filter, and is not in need of an oil change. well the problem continued to persist, Intermittantly of course, sometimes after it would start the service engine soon light would come on, some times it would not. so I keep driving it, last weekend I was meeting my crew at the Mcdonalds before going to a job, I turned the truck off, and It wouldn't start. 3 hours later I went back to the truck. took about 5-7 times cranking the engine before it would start. I took it home to look it over. (check engine light was on at this point) so I park it in the driveway and install my new plug wires, dist. cap and rotor. just a coincedence but now the truck won't start at all! the injector is spitting intermittantly instead of continious pulses, and according to the chiltons manual when I jumper A & B to read the codes I get a code 54, which states :Fuel pump circuit (Low voltage) Probable cause: Sets when the fuel pump voltage is less than 2 volts when reference pulses are being recieved. So what does this mean???? I sold My Firebird which is more simple than these computer controlled vehicles. so all I did was check what wiring I could before it got dark out, and it has been raining ever since, so any advise would be appriciated, I don't want to drop that tank down if I don't have to.

 
Sponsored Links
Joe_F's Avatar
Visiting Guest

Posts: n/a

05-21-03, 04:08 AM   #2  
Joe_F
What does a fuel pressure check with a gauge reveal?

 
HVAC Man's Avatar
Visiting Guest

Posts: n/a

05-21-03, 01:21 PM   #3  
HVAC Man
just got home

I don't have a gas pressure gauge , other than Natural gas for heating equipment, like I said it's been raining ever since, I just got home so I am going to investigate even more. hopefully I'll find a loose ground wire or something.

 
Joe_F's Avatar
Visiting Guest

Posts: n/a

05-22-03, 06:36 AM   #4  
Joe_F
Autozone can rent you the needed fuel pressure gauge.

 
SpiderGear's Avatar
Visiting Guest

Posts: n/a

05-22-03, 10:06 AM   #5  
SpiderGear
Could be a heat sink problem with the fuel pump relay unit!!

While you were at Chiltons did you check for the location of it?

Just a thought!!

 
dirty dan's Avatar
Member

Join Date: Mar 2002
Posts: 438
LA

05-22-03, 03:36 PM   #6  
Sounds like relay problem to me. Should be easy to check with your volt meter. If your sending power to the pump at the relay, check it again at the fuel tank. I think these only send power for a couple of seconds when you first turn on the key.
If your powered at the tank, yank the fuel filter and see if your getting a flow to it when the key is turned on. Be very careful not to ignite the gasoline. If you get no flow, bad fuel pump or clogged pick-up filter. If flow to filter is good check the pressure (also a good time to replace fuel filter). If pressure is good, replace the fuel filter and check flow and pressure at TBI unit.

Good Luck and let us know what you find.

 
HVAC Man's Avatar
Visiting Guest

Posts: n/a

05-22-03, 07:35 PM   #7  
HVAC Man
Thanks Joe for the info, I'll take it into consideration, Spider Gear I wasn't "AT" Chilton's, I have a chilton's Manual. and the book says nothing about a Fuel pump realy heat sink. and Finally Dirty dan, I Put a new fuel filter on it before the problem got worse. so here is the update on it, I read the manual on how to test the fuel pump relay, when I turn key on (not cranking it) I should hear the fuel pump operate for about 2 seconds (a light electrical humming) , well I didn't hear this and I've done it alot of times, so then I hooked up my test light to the wire on the relay which powers the pump and turned on the key, the light Illuminated for about two seconds and then went off, Great I think it's sending power through the relay, but then I take a fused jumper wire and go from the feed wire at the relay to the fuel pump motor, and the motor humms away!, this is good I'm thinking, so I hook the relay back up ,and hit the key and I don't hear the pump humming, so I go and buy a new relay, Install it, and hit the key, the pump Humms this time!!!! I'm getting really excited now, but then the truck still won't start! after cranking for a few minutes and not getting anywhere but a slowly draining battery, I connected my jumper wire at the diagnostic plug to see if my code 54 (low voltage at fuel pump) is still there, and it is not there, I erased the previous code when I disconnected the battery before but the code allways came back when I could'nt start it. and I look inside the throttle body and it's all wet from the gas, (was never like this before) so I know now I am getting the fuel I need ( at least I think I am) so A buddy suggested a few shots of starting fluid, I did, and it still did nothing, Maybe tomorrow I will verify if I am even getting any spark! I know I should have done this before but all roads were pointing me in the direction of the fuel system with the code I got and what not.
GRRrrrr, I'm getting frustrated!!!!

 
HVAC Man's Avatar
Visiting Guest

Posts: n/a

05-23-03, 06:41 PM   #8  
HVAC Man
today I pulled one of the plugs out, and it was all wet, I had my buddy put the plug wire with a plug in it 1/4" away from the engine block, and there was No Spark! so I guess now I have to check the Ignition coil, the ignition module, and the camshaft, and crankshaft position sensors As Per the Chilton's Manual, well I'll be doing so reading uo on this tonite, but I feel I'm closing in on it.

 
billys68ss's Avatar
Member

Join Date: May 2003
Posts: 1,459
WV

05-26-03, 08:22 AM   #9  
Hold on a sec..... I dont think you have a coincidental issue. I think you fixed your problem, but however you created another. If you arent getting spark, and all you have done is replace the wires and cap and rotor. Here is a thought: Go back and pull the distributor cap off and make sure the rotor is there and in the correct orientation. Make sure the wires are in thee correct firing order. I believe this is where you will find your problem.
Hope this helps,
Billy

 
Joe_F's Avatar
Visiting Guest

Posts: n/a

05-26-03, 08:30 AM   #10  
Joe_F
HVAC:

Start with my Basics below.

You should know better than to sell an F body .

 
HVAC Man's Avatar
Visiting Guest

Posts: n/a

05-28-03, 02:57 PM   #11  
HVAC Man
well it ended up being a bad distributer, mine was cracked below the rotor, that steel circular thing. I had the shop replace it. but I left my paperclip in the diagnostic plug when they worked on it, now I have a code 42 IC short or something, did this mess up my truck's computer or something?
cause the check engine light won't go off now, and I disconnected the battery to try and clear it, Yet Another Problem!!!!
thanks

 
HVAC Man's Avatar
Visiting Guest

Posts: n/a

05-28-03, 05:05 PM   #12  
HVAC Man
........also

the truck runs great though, and Joe I know I shouldn't have sold my F Body but I have no room for it , and/or the funds to do what I want with it. trucks running fine I just need to know what this means:
code: DTC 42 Ignition Control (IC)
Probable cause: PCM detects an open or grounded IC or bypass circuit.
Chiltons doesn't say what to do about this code, I'm thinking the code appeared when truck was started, and the paperclip jumper was still in the ALDL connector. like I said the truck runs fine, never had this code before, did the jumper being in there do something bad to my trucks computer?
Thanks to all who helped.

 
ChristopherT's Avatar
Member

Join Date: May 2003
Posts: 171
IN

05-28-03, 05:59 PM   #13  
Re: ........also

Originally posted by HVAC Man
the truck runs great though, and Joe I know I shouldn't have sold my F Body but I have no room for it , and/or the funds to do what I want with it. trucks running fine I just need to know what this means:
code: DTC 42 Ignition Control (IC)
Probable cause: PCM detects an open or grounded IC or bypass circuit.
Chiltons doesn't say what to do about this code, I'm thinking the code appeared when truck was started, and the paperclip jumper was still in the ALDL connector. like I said the truck runs fine, never had this code before, did the jumper being in there do something bad to my trucks computer?
Thanks to all who helped.
The code means that when the truck was started, the ECM detected either a short to ground or an open circuit on the
EST (Electronic Spark Timing) circuit, or the bypass circuit.

Since they did replace the distributor, I'd double check all
the wires to the ignition module under the rotor. (Assuming
you have an HEI ignition.) Look for any Tan/White or all White
wires. If nothing is obvious ask the shop that replaced the
distributor to scan for current codes and go from there.

BTW, what Chilton's manual are you using? I have a copy of
"Chilton's Total Car Care manual (#8252) for the 1982-1995
Chevrolet Celebrity, Buick Century, Olds Cierra, Cutlass Cierra,
Cutlass Cruiser and Pontiac 6000" It's world's better than the
other manuals I've bought. They do make one called "Chevrolet
Pickups 1988-98" that retails for about $25.00 at either
Borders or any other chain bookstore.

Christopher

 
HVAC Man's Avatar
Visiting Guest

Posts: n/a

05-28-03, 06:24 PM   #14  
HVAC Man
Thanks Chris,
I have the new Chilton's 1988-98 full size trucks repair manual 28624 Total Car Care. It's a pretty decent book I guess, it helped me a great deal, I figured that this was the problem with the code I was receiving, the Ignition control module is new, I put it on there and I didn't have that code before, the way I understand it the new distributer didn't include it, I was going to check the connections and so on, and possibly install the old ignition module back on since it wasnt at fault in the first place. I just hope I didn't damage anything having the paperclip in there while the engine was running. BTW I don't think it's an HEI because the coil is sepereate from the distributer (My Firebird had an HEI where the coil was inside the distributer cap) I dunno if this makes it a Non-HEI or not , I guess it would be the same it just has the coil seperate from the distributer. ......well I just looked again it is an HEI with a remote coil.
Thanks for the help.

P.S. I got this Chilton's on eBay for $14.99

 
ChristopherT's Avatar
Member

Join Date: May 2003
Posts: 171
IN

05-28-03, 11:16 PM   #15  
Originally posted by HVAC Man
Thanks Chris,

check the connections and so on, and possibly install the old ignition module back on since it wasnt at fault in the first place. I just hope I didn't damage anything having the paperclip in there while the engine was running. BTW I don't think it's an HEI because the coil is sepereate from the distributer (My Firebird had an HEI where the coil was inside the distributer cap) I dunno if this makes it a Non-HEI or not , I guess it would be the same it just has the coil seperate from the distributer. ......well I just looked again it is an HEI with a remote coil.
Thanks for the help.
P.S. I got this Chilton's on eBay for $14.99
My book outlines a fairly easy diagnostic check to verify the
Code 42 and hunt down the source. Check the "Emission
Controls" chapter if you have one. The code 42 is the same
for TBI and MFI engines, I'm assuming it would be the same
for carburated ones as well. HEI can have remote coils. Let
me know what you find.

Christopher

 
Joe_F's Avatar
Visiting Guest

Posts: n/a

05-29-03, 03:37 AM   #16  
Joe_F
Just look on autolibrary. Should be the same thing and it's free (but not a replacement for the OEM manual ).

 
Search this Thread