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Master Auto Tech
Master Auto Tech, ASE certified Master Technician
Category: GM
Satisfied Customers: 600
Experience:  Over 20 years repairing import and domestic vehicles
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Seven months ago a tuneup was done ($625) and passed smog.

Customer Question

Seven months ago a tuneup was done ($625) and passed smog. One month ago engine begin dying out stops. Fuel pump was replaced. Maintaining the idle (rough) however Engine light came on. Diagnostic was done and fuel pump replaced.
JA: Diagnosing the correct check engine code is the key to getting a quick fix. How many miles are on the car?
Customer: 94,000
JA: Are you hoping to fix this yourself?
Customer: Just did a smog test and was classified as a gross polluter with 1425 reading (should be 115). Mechanic is recommending replacing ECM because he cannot locate the problem.
JA: Is there anything else the GM Mechanic should be aware of about your GM?
Customer: It is a 1989 GMC 5.7 engine
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the GM Mechanic about your situation and then connect you two.
Submitted: 1 year ago.
Category: GM
Expert:  Master Auto Tech replied 1 year ago.
I'm sorry you are having problems with your vehicle. I will try to help.I'm a full time mechanic and have been a mechanic for over 20 yrs and I work part-time here on JustAnswer to help you and others repair their own vehicles, and I get credited by your ratings.. So before leaving the site make sure and leave me a rating. You can still reply to me as many times as neeed, even after the rating.. I will need for you to be my hands and eyes since I'm not there.So if I'm understanding it correctly, it's still running bad and it didn't pass smog test?
Is your vehicle the tbi? (Throttle body injected)I would look at two things first, one pull the distributer out and look at the distributer gear. I have seen these get eaten away till the gears are just razor sharp points. Still would run but poorly.
Then if that's not a problem make sure you don't have a leaky injector if it's throttle body injected. Then I'd replace the computer. They were a weak spot on early gm's.Thanks
Sonny
Customer: replied 1 year ago.
This may help – it is a chronology of events and symptoms
*Seven months ago complete tuneup ($625)
*past smog
*The engine was stalling at stops
*Throttlebody caskets replaced
*solve the stalling problem continue to have rough idle with a pastor jerking periodically (random acceleration)
*fuel pump replaced
*jerking periodically continues
*check engine light appears
*replace heat sensor (analogous to choke)
*check engine light off
*automotive smog inspection to transfer title
*registered as gross polluter should be 115 max and is 1452
Customer: replied 1 year ago.
Correction
This may help – it is a chronology of events and symptoms
*Seven months ago complete tuneup ($625)
*past smog
--- insert- six weeks ago
*The engine began stalling at stops
*Throttlebody caskets replaced
*solve the stalling problem continue to have rough idle with a pastor jerking periodically (random acceleration)
*fuel pump replaced
*jerking periodically continues
*check engine light appears
*replace heat sensor (analogous to choke)
*check engine light off
*automotive smog inspection to transfer title
*registered as gross polluter should be 115 max and is 1452
Customer: replied 1 year ago.
In the chronology submitted injector and throttlebody was inspected and caskets replaced ($645) this solved the stalling
Customer: replied 1 year ago.
I have numbered the line items to help in referencing the conversationThis may help – it is a chronology of events and symptoms
#1 Seven months ago complete tuneup ($625)
#2 past smog
#3 insert- six weeks ago
#4 The engine began stalling at stops
#5 Throttlebody caskets replaced
#6 solve the stalling problem continue to have rough idle with jerking periodically (random acceleration)
#7 fuel pump replaced
#9 periodically continues
#10 check engine light appears
#11 replace heat sensor (analogous to choke)
#12 check engine light off
#13 automotive smog inspection to transfer title
#14 registered as gross polluter should be 115 max and is 1452
Customer: replied 1 year ago.
5 represents the throttlebody solution
Customer: replied 1 year ago.
The mechanic is recommending replacement of the ecm ($635). I have found I can purchase ECM off-the-shelf at AutoZone or O'Reilly for $85. I am told that I can have my vin and mileage flashed from my old unit to the new ECM then reconnect
Customer: replied 1 year ago.
Probably requiring four hours my time saving about $500.
Customer: replied 1 year ago.
I am not a mechanic but have been working on cars for 50 years
Customer: replied 1 year ago.
Customer: replied 1 year ago.
This is a 1989 GM 5.7 (350) engine and I believe TBI
Customer: replied 1 year ago.
Just answer – "I would look at two things first, one pull the distributer out and look at the distributer gear " Is there a reason why my mechanic would not have caught this when he did a complete tuneup item #1.
Customer: replied 1 year ago.
This is a vandura. Not used for commuting or on a daily basis. So from the tuneup and passing smog to gross polluter I have put on 1500 miles.
Customer: replied 1 year ago.
Could the distributor year degenerate that significantly in 1500 miles
Customer: replied 1 year ago.
What is the charge for messaging through this problem. And is the $26 for talk session in addition to that charge
Customer: replied 1 year ago.
Expert:  Master Auto Tech replied 1 year ago.
wow. I'm sorry it just now is showing you replied. But it looks like it was a couple of hrs ago.So to start with, the distributer gear would not of been checked. They only look at the top side of the distributer.How many miles total on the engine?And to answer unfortunately the 26 is in addition. :-/ sorry but we an continue to chat if you want.
Expert:  Master Auto Tech replied 1 year ago.
Oh also the computer is a ripoff at $600. It's an hr job total. The computer is plug and play. You remove the prom from your old computer and install in this one and install in vehicle.
Expert:  Master Auto Tech replied 1 year ago.
Do you still need help with this problem?Thanks
Sonny
Expert:  Master Auto Tech replied 1 year ago.
I strive to provide 5 star service. If I have satisfactorily answered your question please rate it as such and hit submit. Doing so is the only way I get compensated for my time. Also it doesn't close the discussion so we will still be able to communicate if there are further questions.
Thanks
Sonny
Expert:  Master Auto Tech replied 1 year ago.

can I still be of assistance with this problem? was my replies helpful? Thanks Sonny