Did full tune up, now has a stumble
Thread Starter
Pro
Joined: Nov 2010
Posts: 620
Likes: 23
From: MA
Did full tune up, now has a stumble
Hi all.
I bought an 88 last week with 43K miles.
As I've always done when I get an older car, I go through it, which includes tune up.
So I bought all GM AC Delco parts from Top Flight, change cap, rotor, wires, plugs & used CRC on the MAF.
Wires are correct yet now it seems to want to slightly stumble or miss, can't tell, while driving.
I looked for broken vacuum lines, none, tapped the MAF while idling, it didn't stumble & there is no CE light.
Thoughts?
I bought an 88 last week with 43K miles.
As I've always done when I get an older car, I go through it, which includes tune up.
So I bought all GM AC Delco parts from Top Flight, change cap, rotor, wires, plugs & used CRC on the MAF.
Wires are correct yet now it seems to want to slightly stumble or miss, can't tell, while driving.
I looked for broken vacuum lines, none, tapped the MAF while idling, it didn't stumble & there is no CE light.
Thoughts?
Drifting
Joined: Nov 2018
Posts: 1,745
Likes: 642
From: USA
Did one of the new plugs get dropped on the floor or cracked when tightening during the install? You can also look at the inside of the cap for a crack....Run the engine in the dark and look for arcing👍
Melting Slicks
Joined: Oct 2003
Posts: 2,162
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From: Chapel Hill NC
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Id check to see if the spark wires are fully seated on the plugs and in the cap.
Melting Slicks
Joined: Nov 2016
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From: So Cal
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Melting Slicks
Joined: May 2019
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From: Mid-Atlantic
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I've been guilty more than once myself of not reinstalling plug wires so that the boots are all the way seated. Have also crossed wires in the past.
So, yeah, post #s 4 and 5 are worth double, even triple checking. Sometimes the boots feel like they're snapped in but really aren't.
As an aside, I always put a timing light on it whenever I finish swapping out plugs and wires or anything ignition related as well.
So, yeah, post #s 4 and 5 are worth double, even triple checking. Sometimes the boots feel like they're snapped in but really aren't.
As an aside, I always put a timing light on it whenever I finish swapping out plugs and wires or anything ignition related as well.
Last edited by Natty C; Yesterday at 01:44 AM.
Drifting
Joined: Nov 2015
Posts: 1,707
Likes: 327
Finalist 2020 C4 of the Year - Unmodified
An extra bit, look INSIDE the spark plug boots when doing so, make sure the connector is there and good.
I had a less than one year old set and the connector in a boot was pushed back, sidewise. Only kind of worked because it was pushing against the spark plug tip. I only checked because it sounded funny putting back on, now do every time.
I had a less than one year old set and the connector in a boot was pushed back, sidewise. Only kind of worked because it was pushing against the spark plug tip. I only checked because it sounded funny putting back on, now do every time.
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