Just redid the heads in my 87 everything went back together fine. Car idles nice and no vacuum leaks, replaced the coil pack but here's the problem while driving down the road and goingvto wot the car sputters and hesitates and sometime backfires. Checked everything I know of need help!!
Help help !!!
- Thread starter Rayboy87
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williambavila
William Avila (The Buick Guy)
- Joined
- May 11, 2010
- Messages
- 580
Check the connection on your module,try another coil,and check all the hoses to and from intercooler.
start there first
turbofabricator
Well-Known Member
- Joined
- Mar 7, 2004
- Messages
- 4,261
Check:
1) Coil pack/ignition module
2) MAF clamps and hoses from turbo to MAF
3) Grounds. I move ALL of the engine grounds from the back of the pasenger cylinder head to the boss under the coil pack on the intake (for the rectangular wire loom, AFTER filing/sanding all the THICK paint off of the top ) and add a 10 ga. ground wire from this new stud to the battery ground cable at the bottom of the turbo mounting bracket, and add a ground wire from the coil bracket to the new ground location. You CANNOT have too good of a ground path!!!!! Over kill....... is just the right amount.
4) Crank sensor is loose or your thrust bearing is wasted and the crank is walking out of the sensor. (I've seen this a few times over the years.)
5) Fuel pressure issues. Hot wired pump? Clogged filter, bad pump, boost reference hose to pressure regulator is cracked/split, dirty injector, ect.
6) Ignition module / Coil pack. See item #1
1) Coil pack/ignition module
2) MAF clamps and hoses from turbo to MAF
3) Grounds. I move ALL of the engine grounds from the back of the pasenger cylinder head to the boss under the coil pack on the intake (for the rectangular wire loom, AFTER filing/sanding all the THICK paint off of the top ) and add a 10 ga. ground wire from this new stud to the battery ground cable at the bottom of the turbo mounting bracket, and add a ground wire from the coil bracket to the new ground location. You CANNOT have too good of a ground path!!!!! Over kill....... is just the right amount.
4) Crank sensor is loose or your thrust bearing is wasted and the crank is walking out of the sensor. (I've seen this a few times over the years.)
5) Fuel pressure issues. Hot wired pump? Clogged filter, bad pump, boost reference hose to pressure regulator is cracked/split, dirty injector, ect.
6) Ignition module / Coil pack. See item #1
standupjskiguy
Member
- Joined
- Mar 18, 2009
- Messages
- 237
cruising, then wot? sputters and backfires?It sounds like it's suddenly going lean.
Throttle position sensor tells the computer that you've opened the throttle and it needs to add fuel.
MAP sensor responds to vacuum drop to do the same thing.
MAF helps fine tune based on air density. I don't think this is a problem.
I'd check the vacuum line to the map sensor first.
Then check your TPS settings.
And check the vacuum line to the fuel pressure regulator as a vacuum drop is supposed to richen the mixture also.
Since it didn't do this before you did the work, it might just be something you did while putting it back together.
Throttle position sensor tells the computer that you've opened the throttle and it needs to add fuel.
MAP sensor responds to vacuum drop to do the same thing.
MAF helps fine tune based on air density. I don't think this is a problem.
I'd check the vacuum line to the map sensor first.
Then check your TPS settings.
And check the vacuum line to the fuel pressure regulator as a vacuum drop is supposed to richen the mixture also.
Since it didn't do this before you did the work, it might just be something you did while putting it back together.
