truck starts intermittently
Asked by coolslider May 10, 2016 at 06:17 PM about the 1997 Chevrolet C/K 1500 Silverado Extended Cab LB 4WD
Question type: Maintenance & Repair
97 chevy Silverado half ton replaced fuel filter, pressure holds 53 psi. cam shaft crank shaft correlation fault. 02 sensor code lean bank 1. but none of those are really my issue believe it or not. when I go to start my truck I turn the key if I hold the key down it will fire and run idles a little rough but runs. the problem is when I turn the key and I prematurely cancel the ignition cycle by letting off the key to soon I run into nothing but problems my truck has a mind of its own I hook up a battery charger with 200 amp engine start and jumper cables to my other car 2 gauge jumper cables. I crank it endlessly it will sputter but never start I do this 3 times I day for 1 week and at some point on day 3-7 it will one of these times start up and be fine until my stupidity kicks in and I shut the key off mid crank again. now in the 1-7 days of attempted starts I use starting fluid 10% of time I spray I get a putt out of the engine but that is it. never starts until it wants to its like a temperamental 2 yr old.
19 Answers
Sounds like you have a fuel issue. 53 lbs of fuel pressure is not enough. It needs 58 to 63 lbs. You get under 56 lbs and then you have the hard starting. Should do a fuel pressure bleed down test by hooking up the fuel pressure gauge and see if it holds pressure. It should not drop more that 5 lbs in 3 minutes. If it does then the spider assembly is leaking and also would cause hard starting.
Auto_Centric answered 8 years ago
Ok my shot in the dark might as well guess too CKP (crankshaft position sensor) one of two (active) sensors AC volt output signals computer when to send spark! BUT you really should... Have it read for codes, even if the check engine light is NOT on the computer will have stored information and codes. Discount auto stores will read codes for no fee. write them down.
I agree, it would be nice to have the code or codes. Does sound like a crankshaft & cam sensor, on top of the fuel pressure issue.
coolslider answered 8 years ago
as stated I do have 2 codes one fore crank to cam correlation fault and lean bank 1 code but the perplexing part is the catalyst the thing that causes me such hardache with with is only when I prematurely stop the startup procedure by shutting off the key early if I don't jump the gun and let go of the key to soon I never have a problem
coolslider answered 8 years ago
but that one off day I am in a hurry and let go of the key to soon im stuck without a car for a cpl of days
coolslider answered 8 years ago
and I do get spark while cranking I found this out one rainy afternoon cranking endlessly grabbed distributor cap and got about 30 quick jolts from finger to elbow were it was touching the frame
You still have a fuel pressure issue, and still would like to know the codes.
Cam/crank correlation is a serious code. Just saying
coolslider answered 8 years ago
not the issue thou bc it idles fine no misfires or anything at all fuel pressure is 55psi and the manufacturer spec is 55-65 so im on the low end of optimal high end of functional
Ok what did the bleed down test show on the fuel pressure?
coolslider answered 8 years ago
remained 55\54 psiright between the 2 held there for 20 min so not leaking injector. like said once cranking even starting fluid doesn't sputter or anything but im getting spark its weird as if the starting fluid isn't reaching the pistons but that would only happen if the cam shaft wasn't spinning but if cam shaft isn't spinning the distributor wouldn't be turning and thus the sparks wouldn't be firing
coolslider answered 8 years ago
according to a post on chevys forums these truck average 52-57 psi on new pumps even so I doubt its my pump
Wrong on the fuel pressure issue. Hard starting after pressure gets below 56 lbs. But what ever, ya something else is going on if starting fluid does not make the engine fire off. And yes, agree that there is not a problem with the spider injection. See, I have to know these things since I am only behind this screen. So as Andrew was saying about the cam and crankshaft sensor correlation, has that ben corrected? That is definitely a problem. Have you replace the sensors starting with the crankshaft sensor? That is the one that usually goes bad. Also just check compression in a few cylinders to know what is going on.
coolslider answered 8 years ago
compression check comes up good replacing sensors in 2 weeks crank shaft sensor 23$ and distributor full assembly 45$ been driving it flawlessly without problems for last week as stated only goes down the drain if I prematurely cut off the ignition mid crank rpm gauge does seem to be a little sluggish on its response to engine change but not audible or feelable delays in power or responce
coolslider answered 8 years ago
www.am-autoparts.com cheap warrantied parts with free shipping they compete with rockauto and are usually cheaper than rock auto ordered the sensor and distributor paid am-autoparts 65$ autozone 212$ obvious purchase lol
coolslider answered 7 years ago
issue resolved key module black box under key not working replaced ignition module problem solved