no start issue after header install
Thread Starter
Pro
Joined: Mar 2005
Posts: 721
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From: Fla
no start issue after header install
I have a 2003 vert with a completely stock engine. My mechanic replaced the stock exhaust system with a complete longtube header system and catback. o2 sensors where put back in place, left on the left and right on the right is what my mechanic said... the car cranks but does not start... says low fuel and the check engine light is half lit not brightly lit like it should be. Its like its in limp mode or something... tried pluging in engine diagnostic meters and it does not recognize them.... checked all grounds, wires,, it is something electronic for sure so any possible ideas would be greatly appreciated. I know there are lots of sharp people in this forum so I am sure one of you have the answer. the cats were removed but o2 sensors are in... water pump was also replaced along with new tensioner. all coils were checked so just lost for words at the present moment. thanks. ed. the car is an automatic trans car.. radiator was also replaced for a larger one.
Thread Starter
Pro
Joined: Mar 2005
Posts: 721
Likes: 70
From: Fla
he said he checked all the grounds and they were tight. its strange that the tech 2 when its plugged in is not being recognized by the computer... maybe a blown fuse or something.. a strange issue for a car that has run perfect all of its life. long tube headers not really worth it. regret i did this but i need to continue since the damage is done.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,626
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From: Cape Coral, Florida
If your mechanic can’t connect to the car with the scan tool there is a communication issue between the scan tool and cars many modules...I’m just trying to figure out which one with some exhaust work...gas gauge on E and power windows not working and water temp maxed out is a sign with the key on...tell your mechanic to watch this video...I’m not sure if he good at diagnostics but he’s going to have to access both splice packs next to the BCM and he can use a voltmeter and or a labscope to see what’s going on with the serial data line...what I’m saying is probably French to you but your mechanic may know something about this...if he has questions he can reach us here as to the procedure...the data line is either shorted to power or to ground or a module (PCM ?) is missing a power or ground...that power or ground will backfeed into the data line and cause your problems !!...that data line is pin 2 on the DLC (where he hooks up his scan tool too)...he should not see 12 volts there or ground (should read in the thousands of ohms)...where in the great state of Florida are you located ??...now that I’m thinking the PCM is grounded to the right side of the block near the starter...that could be the issue...I believe there are 3 wires there attached to the block !!
Last edited by C5 Diag; May 29, 2021 at 05:58 AM.
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Helpful post above
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From: Cape Coral, Florida
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Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,626
Likes: 4,069
From: Cape Coral, Florida
he said he checked all the grounds and they were tight. its strange that the tech 2 when its plugged in is not being recognized by the computer... maybe a blown fuse or something.. a strange issue for a car that has run perfect all of its life. long tube headers not really worth it. regret i did this but i need to continue since the damage is done.
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he said he checked all the grounds and they were tight. its strange that the tech 2 when its plugged in is not being recognized by the computer... maybe a blown fuse or something.. a strange issue for a car that has run perfect all of its life. long tube headers not really worth it. regret i did this but i need to continue since the damage is done.
And this are the grounds by the starter
Racer
Joined: Aug 2015
Posts: 323
Likes: 68
From: Sacramento California
I know you said all the grounds were checked. May be worth double checking. With long tube headers the air system valves (or whatever they are called) are usually removed. The bolt on the driver's side head that holds down the bracket for the air system hose also holds a ground. With the bracket removed even with that bolt tightened back down that ground can still be loose in there. Good luck.