C4 driving me insane. Help!
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 25
Likes: 0
From: Scranton PA
C4 driving me insane. Help!
Hello guys, I'm new to the whole vette scene.. Diesels are more my thing, so Ide just like to say that I'm glad to be a part of the community. Therefore, the reason I am posting today is because my new project a 1985 C4 TPI is not working with me. I bought it and drove it home about an hour away. It ran good, just needed some things so I thought. I installed an slp ram air, MA Modified MAF, New plugs, new wires, new distributor cap and when I went to start it up it will idle not perfectly smooth but not bad either, but the main issue is that there is no throttle response. As soon as you press the throttle it Boggs down and even stalls. It seems to me that the cylinders aren't firing properly even though I am positive that I have the firing order correct. Could it be a timing issue? Fuel pressure? I don't know and I need to get this car running! Thanks in advanced guys.
Vlad
Vlad
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
Hello guys, I'm new to the whole vette scene.. Diesels are more my thing, so Ide just like to say that I'm glad to be a part of the community. Therefore, the reason I am posting today is because my new project a 1985 C4 TPI is not working with me. I bought it and drove it home about an hour away. It ran good, just needed some things so I thought. I installed an slp ram air, MA Modified MAF, New plugs, new wires, new distributor cap and when I went to start it up it will idle not perfectly smooth but not bad either, but the main issue is that there is no throttle response. As soon as you press the throttle it Boggs down and even stalls. It seems to me that the cylinders aren't firing properly even though I am positive that I have the firing order correct. Could it be a timing issue? Fuel pressure? I don't know and I need to get this car running! Thanks in advanced guys.
Vlad
Vlad
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 25
Likes: 0
From: Scranton PA
I changed the maf being that it ran much better unplugged when I bought it. I didn't touch anything that shouldn't have been touched, I just can't wrap my head around why it is running like this. The firing order is correct I checked multiple times, the plugs are gapped .35 and I even bought another set of wires.. I really am out of ideas?
Race Director
Joined: Sep 2001
Posts: 10,560
Likes: 439
From: Wellington, FL
St. Jude Donor '11 thru '25
I changed the maf being that it ran much better unplugged when I bought it. I didn't touch anything that shouldn't have been touched, I just can't wrap my head around why it is running like this. The firing order is correct I checked multiple times, the plugs are gapped .35 and I even bought another set of wires.. I really am out of ideas?
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 25
Likes: 0
From: Scranton PA
Actually, being that I switched out the MAF.. Would disconnecting the battery to reset the ECM work? I'm unsure how these engines act, I just know that with my cummins and pstroke. Resetting the battery works for practically everything haha
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
Corvettes 'tell' you quite a bit about their problems.
Check for codes:
http://www.gnttype.org/maint/malf.html
Check for codes:
http://www.gnttype.org/maint/malf.html
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 25
Likes: 0
From: Scranton PA
Corvettes 'tell' you quite a bit about their problems.
Check for codes:
http://www.gnttype.org/maint/malf.html
Check for codes:
http://www.gnttype.org/maint/malf.html
Safety Car
Joined: Aug 2002
Posts: 3,842
Likes: 230
From: SANTA CRUZ CA
http://www.gnttype.org/maint/malf.html#13
That is not the normal sequence of flashes for code diagnostics.
Code 12 starts the process.
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 25
Likes: 0
From: Scranton PA
One last thing I tried before it got to dark was to start it up with the new maf unplugged. It idled pretty nice, but as soon as I gave it some throttle it bogged out.. So that means it has to be something with the maf? It may be faulty or could the connection be bad being that I don't think there are relays for the maf in an 85? Sorry to keep pressing the issue, I'm just disgusted by the fact my whole weekend has been shot trying to get this thing going.. I just wanna drive!
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
I'm sure that's what the OP meant. I doubt that he has a 1/3" gap.
As long as the plug gap is under .050" and there IS a gap, it shouldn't cause the symptom that is being described here.
Here is another vote to RE CHECK AGAIN, plug wire routing. Also check timing and fuel pressure. These are basics. First things you should check.
As long as the plug gap is under .050" and there IS a gap, it shouldn't cause the symptom that is being described here.
Here is another vote to RE CHECK AGAIN, plug wire routing. Also check timing and fuel pressure. These are basics. First things you should check.
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 25
Likes: 0
From: Scranton PA
Thanks for all the input guys, I just checked the 3 wires in the cap and found that the bottom wierd shaped prong has no wire connected and a black wire is not connected to it.. The other two prongs are wired? And what is the best way to check for a vacuum leak? Thanks again y'all
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 25
Likes: 0
From: Scranton PA
Alright guys, update after I just put the floodlights away and awoke all my neighbors. The vette seems to be running much better, timed it and it has a rather snappy throttle.. I was unable to take it out for a test drive being that after all the mishaps I have bad with it I now have gas in my oil. However when I fired it up, it ran nice with a 55 rpm and accelerated nicely in nuetral however I have smoke coming from what seems to be the pass. Side and the exhaust fumes smell wicked rich. Could this just be carbon build up? A bad o2? Anything else, I would greatly appreciate input. Was thinking of sea foaming the engine to clean it out and see any leaks, good idea?