TPI Tuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
Sponsored by:
Sponsored by:

TPI bogging!!!!

Thread Tools
 
Search this Thread
 
Old 07-07-2002, 11:12 PM
  #1  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
TPI bogging!!!!

I fixed quit a few problems with my 86 IROC with a swapped out 350 and the 305 TPI setup with some extras (I'm fixing someone elses mistakes). When the engine is cold it starts right up, after a few seconds idles down to about 650 RPM, then I put it in drive and when i push on the gass it bogs down. It doesn't stall or back fire and I could drive it, but I'm not even throwing any codes. Then when I turn the car off and try to restart it, it won't fire until I let it sit for about 20 minutes to a 1/2 hour. I've changed the ignition module twice thinking the first one was bad and still the same problem. I checked the TPS and it's at .56 volts, and I've set the initial timing in drive at 650 RPM at 6 degrees advanced. The only problem is when I hook the EST back up and start the car, the computer advances the timing to 12 degrees advance and it runs pretty choppy. I've changed many many parts, and I think the timing advancing is my problem, but what causes it? Please help, I'm so close with finishing all of the fixes, this hopefully will be the last.
Old 07-08-2002, 07:09 AM
  #2  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
Come on you guys, atleast one of you had to have heard of this.
Old 07-08-2002, 08:15 AM
  #3  
Member
 
SMOKEN's Avatar
 
Join Date: Apr 2002
Location: SUDBURY
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
i got that same problem on my 86 305 tpi trans am i even put back the original chip now when my mechanic screwed around with the timing it was retard 4 degrees but the car was quick now my car runs 16.10 slow for a 86 305 tpi with 3.42 gears
Old 07-09-2002, 12:09 PM
  #4  
TGO Supporter

 
Desert86Roc's Avatar
 
Join Date: Jul 1999
Posts: 607
Likes: 0
Received 0 Likes on 0 Posts
Have you checked your fuel pressure? You might want to invest in, or borrow, a scanner so you can see what is going on.
Old 07-09-2002, 12:53 PM
  #5  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
I checked it last night, with the key in the on position without starting the car, it read consistently at 39 psi. I've heard these cars take 40 to 45 psi, is this still ok?
Old 07-10-2002, 02:44 PM
  #6  
Senior Member

 
Jon92TA's Avatar
 
Join Date: Jul 2001
Location: OC, CA
Posts: 783
Likes: 0
Received 1 Like on 1 Post
Car: 92 Trans Am - Sold
If I'm reading this right, you have a TPI from a 305 on a 350? The first thing that came to mind was that the 305 uses 19# injectors vs the 22# for a 350. Couple that with the low fuel pressure sounds like it may be the problem, it's running too lean. I'm sure someone could elaborate a little more.
Old 07-10-2002, 03:20 PM
  #7  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
I should have included this, but I'm not positive on this. According to the previous owner, he put Corvette injectors in it, which should be 22 lb./hr. I'm finally breaking down and taking it to my mechanic Friday because I don't even want to look at the car anymore let alone work on it. When and if I find out what the problem is, I'll be sure to repost it. Thanks for the reply though.
Old 07-11-2002, 09:48 PM
  #8  
TGO Supporter
 
StylnCamaro's Avatar
 
Join Date: Sep 2001
Location: PA
Posts: 84
Likes: 0
Received 0 Likes on 0 Posts
This sounds stupd but check your oil, if you have to much even by a half a quart it'll do this and the car shake and bog around 1500-2000 rpm...I had the same thing happen to me when my fiance wanted to suprise me by takin it to sears for an oil change...BIG SURPRISE!!!!! I only had to redue the oil and filter my self
Old 07-12-2002, 08:34 AM
  #9  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
That sucks, I checked the oil and it checked out ok, but thanks for the advice. Never take you car to Sears.
Old 07-12-2002, 01:30 PM
  #10  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
Well, I got a call from my mechanic today, he said it's either the cam or a broken valvespring . I'll either be buying parts from Summit or I'll be in the market for a new engine, depending on how much he'll charge to install a new cam. As I hear more I keep you posted.
Old 07-16-2002, 03:08 PM
  #11  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
Well guys, the cam is gone and the rocker studs are beginning to come out of the heads. So now I'm going to part out the car because I don't want to put out any more money. Thanks again for all of your help.
Old 07-22-2002, 02:44 PM
  #12  
Member
Thread Starter
 
felo72's Avatar
 
Join Date: Jun 2002
Location: Warren, OH
Posts: 242
Likes: 0
Received 0 Likes on 0 Posts
Change in plans!!!!!

While I was tearing into the engine to get it out, I noticed an externally balanced damper, so I looked at the flex plate and noticed that was externally balanced too. So I tore into it more and noticed forged .100 in. domed pistons, by *** it's a 383!!! So now I'm going to throw a new cam and lifters in for $130 and the heads are going to the machine shop today to get screw in studs and have the valve springs checked for $80. I'll probably get a new EPROM burned for it, but it seemed to run pretty good without a custom chip. We'll see.
Old 07-22-2002, 09:41 PM
  #13  
Member
 
phoenix350's Avatar
 
Join Date: Feb 2002
Location: Illinois
Posts: 159
Likes: 0
Received 0 Likes on 0 Posts
good call....good call...glad u decided to stay
Old 07-23-2002, 10:20 AM
  #14  
Supreme Member
 
5SIZ's Avatar
 
Join Date: May 2002
Location: Tucson
Posts: 1,512
Likes: 0
Received 0 Likes on 0 Posts
Car: 1987 IROC-Z
Engine: 305 TPI
Transmission: T5
great discovery!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Infested
Tech / General Engine
3
05-22-2018 11:56 PM
777Shock777
Tech / General Engine
4
10-29-2015 04:30 PM
GouldyGTR
DFI and ECM
3
08-21-2015 10:43 PM
Out-Cast
Tech / General Engine
5
08-17-2015 10:57 AM
Sanjay
Engine/Drivetrain/Suspension Parts for Sale
1
08-12-2015 03:41 PM



Quick Reply: TPI bogging!!!!



All times are GMT -5. The time now is 02:16 AM.