spuddering (missing at WOT)
#1
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Member
Joined: Sep 2008
Posts: 238
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From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
spuddering (missing at WOT)
I have a 88 Firebird TBI WC-T5. So I have been having a problem. When i give it gas (WOT) the car starts to spudder like it is missing on a cylinder. I have re-placed the wires, plugs, cap, rotor, coil all with MSD parts. Even at idle if i try to rev the engine, it wants to stumble at WOT around 2750 - 3250 RPM's. Any ideas or tips will be greatly appreciated. - RUSS
#2
Thread Starter
Member
Joined: Sep 2008
Posts: 238
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From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
So i still have my problem. I changed my wires out for a new set ( thinking i may have screwed them up crimping them ). That seemed to help at idle. I was able to rev the engine up to 4500rpm's at WOT ( wide open throttle ). So i went on a test drive, and what do you know? problem still exists. Here is some info on my car. 88 Firebird SE , TBI, WC-T5 114,000miles.
Things i have done to my car: Edelbrock 3704, MSD ignition system & 8.5 wires less distributor and control box, K&N filter in the stock housing, NGK V-Power Plugs, New EGR valve, IAT sensor, TPS sensor, CTS sensor, Re-built TB, New radiator,
Things i have done to my car: Edelbrock 3704, MSD ignition system & 8.5 wires less distributor and control box, K&N filter in the stock housing, NGK V-Power Plugs, New EGR valve, IAT sensor, TPS sensor, CTS sensor, Re-built TB, New radiator,
Last edited by akmusclecar; 12-08-2008 at 11:50 AM. Reason: Wanted to put more info on my car in.
#6
Supreme Member
Joined: Jan 2006
Posts: 3,341
Likes: 10
From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
YOUR ENGINE IS MISSING? I DIDN'T TAKE IT!
When it’s missing take a look at the tach.
Does the RPM smoothly drop or is the tach erratic.
(It helps to use a racing tach with a fast response time because the stock tach might be damped).
Anyway if the tach is erratic when the miss occurs I would suspect the MSD.
.
Happy Racing!
.
- Race clean!. . . . . . . . . Do it on dirt! -
#7
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: YOUR ENGINE IS MISSING? I DIDN'T TAKE IT!
To give some more info. the car starts missing if i press more than a 1/4 ". In neutral revving the engine on brings the rpm's to around 3300-3500. could this be my ign. module going out? I don't want to spend the 250+ on a MSD dist. Any thought to my situation is greatly appreciated.
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#8
Member
Joined: Jun 2008
Posts: 172
Likes: 0
From: Chattanooga TN
Car: 87 GTA
Engine: 350 Tune port
Transmission: 700r4,2500 stall
Re: YOUR ENGINE IS MISSING? I DIDN'T TAKE IT!
To give some more info. the car starts missing if i press more than a 1/4 ". In neutral revving the engine on brings the rpm's to around 3300-3500. could this be my ign. module going out? I don't want to spend the 250+ on a MSD dist. Any thought to my situation is greatly appreciated.
#9
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
I know the fuel System is good. I have replaced EGR valve, IAT, CTS, TPS, Re-built the TB, new fuel filter, I run a K&N in the stock housing to a cone filter by the carbon canister. I have checked that the spray patter is in a nice cone shape. I just bought a new Ign. module hopefuly that is my problem.
#11
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Well that would also be a good idea. But seeing that all of this car was stock when i bought it, i figured it could use the new parts anyway. I also live in Anchorage, Alaska where i have to meet the same standards of California Emissions. Anyhow I have just replaced my "factory" ign. module to no avail. I will post a video of what is going on so everyone can see my problem.
#12
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Member
Joined: Sep 2008
Posts: 238
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From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Here is a vid of my problem. This is at wide open throttle.
http://s495.photobucket.com/albums/r...Carproblem.flv
Edit: So i checked to see if i had any codes stored. I pulled up 23,24,33, and finally 42.
23- manifold air temperature sensor
24- Vehicle Speed Sensor ( speedo flutters when the dash is hot )
33- map- baro sensor
42 est ( thought it may have been timing so i know why this is showing )
Off to the parts store.i will keep this updated
http://s495.photobucket.com/albums/r...Carproblem.flv
Edit: So i checked to see if i had any codes stored. I pulled up 23,24,33, and finally 42.
23- manifold air temperature sensor
24- Vehicle Speed Sensor ( speedo flutters when the dash is hot )
33- map- baro sensor
42 est ( thought it may have been timing so i know why this is showing )
Off to the parts store.i will keep this updated
Last edited by akmusclecar; 12-09-2008 at 03:36 PM.
#13
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Member
Joined: Sep 2008
Posts: 238
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From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
So I replaced my map sensor and still have the problem.... Maybe even worse. I can't figure this out. I am going to replace the manifold temperature sensor here in the next hour. Hopefully that helps!? If anyone has any suggestions they would be appreciated. - RUSS
Edit: I also made sure i am at TDC and all my wires were in the right order.
Edit: I also made sure i am at TDC and all my wires were in the right order.
#14
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Ok. so it was snowing last night, and i didn't get my manifold air temperature sensor on. I need some help trying to diagnose this. Hopefully someone will see what is happening in the video i posted and chime in.
#15
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Joined: Nov 2006
Posts: 69
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From: East central, WI
Car: 89 Camaro RS
Engine: TURBO 94 LT1
Transmission: T-56 6 Speed
Axle/Gears: 10 bolt 4.10
Re: spuddering (missing at WOT)
Check the fuel pressure and make sure it's steady. If it drops badly, replace the fuel pump.
Test intake manifold vacuum at idle and let me know what it's at
Test intake manifold vacuum at idle and let me know what it's at
#16
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Unfortunately I do not have acess to a vac/ boost gauge or fuel pressure gauge.
#17
Thread Starter
Member
Joined: Sep 2008
Posts: 238
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From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
23- manifold air temperature sensor
So... I replaced this also. Still no help. I am getting pretty frustrated now. grrrr. I am honestly at a loss to what the cars' issue is.
So... I replaced this also. Still no help. I am getting pretty frustrated now. grrrr. I am honestly at a loss to what the cars' issue is.
#18
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iTrader: (1)
Joined: Nov 2006
Posts: 69
Likes: 0
From: East central, WI
Car: 89 Camaro RS
Engine: TURBO 94 LT1
Transmission: T-56 6 Speed
Axle/Gears: 10 bolt 4.10
Re: spuddering (missing at WOT)
Your wasting your time just throwing parts at it. What you need is some test equipment so we can possibly help you.
Don't you have a parts store that will loan out tools like auto zone.
Or you could take your car to reputable shop.
Don't you have a parts store that will loan out tools like auto zone.
Or you could take your car to reputable shop.
#19
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Seeing that i am going to keep this car as long as it is running. I don't consider any repair "wasting time or money". I have a 21 year old car, If it ain't broke now it will be soon. As for parts stores, they are no help around here. And to the reputable shop.... I have been doing my own car repairs since i was 13 driving my first car a 83 jeep cherokee. I doubt your labor costs are $80-90/HR for a cheap shop. I don't trust anyone doing work on my cars either. But anyways. - Russ
#20
Junior Member
iTrader: (1)
Joined: Nov 2006
Posts: 69
Likes: 0
From: East central, WI
Car: 89 Camaro RS
Engine: TURBO 94 LT1
Transmission: T-56 6 Speed
Axle/Gears: 10 bolt 4.10
Re: spuddering (missing at WOT)
Seeing that i am going to keep this car as long as it is running. I don't consider any repair "wasting time or money". I have a 21 year old car, If it ain't broke now it will be soon. As for parts stores, they are no help around here. And to the reputable shop.... I have been doing my own car repairs since i was 13 driving my first car a 83 jeep cherokee. I doubt your labor costs are $80-90/HR for a cheap shop. I don't trust anyone doing work on my cars either. But anyways. - Russ
I've been working at a shop for 11 yrs and am one of the owners now. But I grew up here too and was in the shop as a child.
Just out of curiosity I did a gross sales chart for the last 11 yrs.... Yea sold $8.8m in repair work
Here's what it boils down to either get some test equipment so you know what direction to go or stop whining that no one can help you.
#21
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Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Ok so i got a boost/vacumm and air/fuel gauge this morning. I am at work so I won't be able to hook anything up until i get off. And to " slick" I only have spent around $150 for my sensors, Holley fuel pump# 12-903 and my gauges. Oh wait.... you are an owner of a repair shop, I see why you would think that I would have to spend $200 just for a manifold temp sensor and map/ baro sensor ( mark-up costs ). You sir are the reason i don't have any shops working on my car. Some of us don't have the money to spend for (you) a shop to work.... oh wait diagnose our cars. I will spend $200 of my hard earned money on parts i might or might not need, before i go and let a shop have my car for a undetermined amount of time. I do understand as a shop owner you would like to keep as much $ in your line of work as possible. I have no hard feelings about it. I just cannot justify bringing my car to a shop to have them tell me it could be a simple problem. Then i would look like an . - Russ
#22
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Update: I istalled a air/fuel gauge to see if the car was leaning out or running rich. At idle the gauge stays around the normal mark, but when i give it gas she leans out pretty bad. It looks like i am going to install the Holley 255lph pump i picked up this weekend. How long should it take to drop the tank if i cut the exhaust? And is there any common problems i will probally have getting the tank out? any help is appreciated . -Russ
#25
Thread Starter
Member
Joined: Sep 2008
Posts: 238
Likes: 0
From: Anchorage, Ak
Car: 1988 Pontiac Firebird
Engine: 5.0 TBI
Transmission: W/C T5
Axle/Gears: 3.08 Posi
Re: spuddering (missing at WOT)
Yes I finally got it figured out. Damn fuel pump. I started to unbolt the rear-end components... Then as i struggled to get the tank out of the way I see the hole where the last owner cut the "access hole". Well unfortunately i had to clean up the hack job the last owner left. I finished pulling the pump to find the strainer was fully clogged. Installed the new pump, put all back together and now my bird has all the power i want, when i want it.
#26
Member
Joined: Jun 2008
Posts: 172
Likes: 0
From: Chattanooga TN
Car: 87 GTA
Engine: 350 Tune port
Transmission: 700r4,2500 stall
Re: spuddering (missing at WOT)
Yes I finally got it figured out. Damn fuel pump. I started to unbolt the rear-end components... Then as i struggled to get the tank out of the way I see the hole where the last owner cut the "access hole". Well unfortunately i had to clean up the hack job the last owner left. I finished pulling the pump to find the strainer was fully clogged. Installed the new pump, put all back together and now my bird has all the power i want, when i want it.
#27
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Joined: May 2008
Posts: 31
Likes: 0
From: virginia beach, va
Car: 92 25th anniversary z28!!
Engine: 5.7L 350
Transmission: 700R
Axle/Gears: stock
Re: spuddering (missing at WOT)
yeah your timing might be off, did you make sure it was at TDC before you put back in the distributor and mark the distributor and plugs? you might have the wrong firing order or the distributor is too far advanced or retarded, i know it sounds dumb but i know if have forgotten to do it before!! also did you mess with any gaskets or anything?
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