Car backfires and dies!
Car backfires and dies! I just got done installing heads. Now my car will run horribly for a second or two, backfire and just die. Both the IAT and the ECT read around -41F. I have tried swapping both sensors with known working ones. I have checked for ground/continuity in both the sensors and the ECM grounds. I have no DTC's present.
Anyone have any ideas?
Anyone have any ideas?
I have a total of 3 individual wires that I have grounds to the back of the heads. I checked for continuity in all the ECM grounds. All of the ECM grounds are in fact grounded.
Yes, the (-) cable had been off for about 2 months.
Yes, the (-) cable had been off for about 2 months.
Last edited by Herper84; Dec 17, 2007 at 03:47 PM. Reason: more info
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Verdad Gallardo Car doesn't have a distributor, pushrods are 7.325 dead on the money (checked with a length checker), Plug wires were all labeled before being taken off so there is no way they are in the wrong sequence. There are no codes so it's not a misfire or a sensor being unplugged or a bad sensor. I ran the ECM with HP Tuners and all the sensors are within normal limits except for IAT and ECT. I'm at a loss here. I only took off the heads/intake. I didn't touch any of the timing components.
Keep the suggestions coming! I appreciate all the help!
Keep the suggestions coming! I appreciate all the help!
Last edited by Herper84; Dec 17, 2007 at 06:24 PM. Reason: more info
Staging Lane
Joined: Nov 2007
Posts: 52
Likes: 0
From: FT Bragg, NC.
sorry still transing from the 88, i would jsut go over the wires again, jsut ot be sure, i mean it sounds like timing, thats the only other thing it oculd valve open when its suppose the closed, i am also thinking rocker arms, not tight enough, or over tight, so its not opening or staying open, again im just guessing havent had the pleasure of thanking my LS1 apart....YET
I can't even get the car to idle for more than a second or two. The ECT will dump fuel in the car if it's cold like -41F. My main concern is why both the IAT and ECT are reading all messed up.
people forget a backfire can be caused by a vaccumm leak . . . are all your gaskets sealed correctly? did you sequence the bolts correctly? did you drag the ***-end of the manifold when you put it back on?
10 Second Club
Joined: Apr 2002
Posts: 1,755
Likes: 2
From: Cincinnati, Ohio
Jumper the IAT/ECT connector and see if you get a high number. If so the sensors are bad, if not check for a 5 volt supply from one side of the connector. If no voltage ohm the wires from the connector to the ECM to check for an open/short.
