TPI Swap Question
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
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From: Arkansas
TPI Swap Question
I’ve got a question about the TPI conversion. Did any of you guys keep / get rid of the EGR system on the engine or did you keep it? If so how about the knock sensor? Does it make a difference to use / not use it?
I was told that the EGR valve was critical to work with the knock sensor to control pinging and not damage your engine. And that using the knock sensor w/o EGR will def harm the engine.
Could someone clear this up for me, I’m a little confused on what to keep or delete to clean things up a bit. I have seen aftermarket harnesses w/o EGR knock sensor provison so that’s confused me even more.
I would have a chip burned to match whatever I do of course. Just want to do this right the first time.
Thanks again
I was told that the EGR valve was critical to work with the knock sensor to control pinging and not damage your engine. And that using the knock sensor w/o EGR will def harm the engine.
Could someone clear this up for me, I’m a little confused on what to keep or delete to clean things up a bit. I have seen aftermarket harnesses w/o EGR knock sensor provison so that’s confused me even more.
I would have a chip burned to match whatever I do of course. Just want to do this right the first time.
Thanks again
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by 1982CorvetteDude
I’ve got a question about the TPI conversion. Did any of you guys keep / get rid of the EGR system on the engine or did you keep it? If so how about the knock sensor? Does it make a difference to use / not use it?
I was told that the EGR valve was critical to work with the knock sensor to control pinging and not damage your engine. And that using the knock sensor w/o EGR will def harm the engine.
Could someone clear this up for me, I’m a little confused on what to keep or delete to clean things up a bit. I have seen aftermarket harnesses w/o EGR knock sensor provison so that’s confused me even more.
I would have a chip burned to match whatever I do of course. Just want to do this right the first time.
Thanks again
I was told that the EGR valve was critical to work with the knock sensor to control pinging and not damage your engine. And that using the knock sensor w/o EGR will def harm the engine.
Could someone clear this up for me, I’m a little confused on what to keep or delete to clean things up a bit. I have seen aftermarket harnesses w/o EGR knock sensor provison so that’s confused me even more.
I would have a chip burned to match whatever I do of course. Just want to do this right the first time.
Thanks again
My understanding is when you have the chip burned you delete both the knock sensor and EGR completely and don't worry about either of them. I'm doing the same thing with my LT1 intake swap.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Keep the knock sensor, however you need one for TPI not TBI I'm pretty sure. I know there is a difference in 350 and 305 knock sensors. I am not running EGR on either of my TPI conversion vehicles. You will need to have EGR (and VATS depending on year) removed from the PROM when you buy it if you aren't going to have EGR. If you do run EGR and a Corvette TPI intake base you have to have special headers or C4 manifolds to get exhaust into the intake because there is no EGR passage in the aluminum Corvette heads, it has an external pipe. If you use an F-body intake and iron heads you don't need anything extra for EGR, there is a passage in the heads and in the intake base.
If you do a search on my user name and TPI you should find my C3 TPI "primer". It has lots of interesting info.
http://forums.corvetteforum.com/show...&highlight=tpi
If you do a search on my user name and TPI you should find my C3 TPI "primer". It has lots of interesting info.
http://forums.corvetteforum.com/show...&highlight=tpi
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by Durango_boy
My understanding is when you have the chip burned you delete both the knock sensor and EGR completely and don't worry about either of them. I'm doing the same thing with my LT1 intake swap.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by markdtn
Why would you kill the knock sensor? It controls timing.
You're right about the knock sensor. I went back and checked my notes. The guy doing my harness and computer said he was deleting a knock sensor, but after checking, I found he is deleting one, of the two. So instead of two sensors I am deleting one, to leave one.
My bad...sorry for the confusion.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by Durango_boy
You're right about the knock sensor. I went back and checked my notes. The guy doing my harness and computer said he was deleting a knock sensor, but after checking, I found he is deleting one, of the two. So instead of two sensors I am deleting one, to leave one.
My bad...sorry for the confusion.
My bad...sorry for the confusion.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
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From: Arkansas
Thanks for the quick replies guys, my swap is actually TBI but since it's not a popular swap and TBI/TPI are pretty much the same except for number of injectors I thought I'd reference TPI instead.
This was the reply I got on the F-Body site
"Stock ECM will want to have a complete car, else it will tell you.
Check Engine light will never go out.
Detonation will not be in check (by the EGR) so ECM will have to retard timing to reduce detonation (happens AFTER detonation is detected).
Since your timing will be retarded, your power will be decreased.
Since your EGR will no longer be keeping detonation down, your engine will detonate more (destructive)."
I'm still pretty sold on deleting EGR (keeping knock sensor) because the corvette fever article on TBI swap made no mention of EGR (but did list the knock sensor as a required part) and said they had a custom chip burned. It's the same swap that I'm doing.
This was the reply I got on the F-Body site
"Stock ECM will want to have a complete car, else it will tell you.
Check Engine light will never go out.
Detonation will not be in check (by the EGR) so ECM will have to retard timing to reduce detonation (happens AFTER detonation is detected).
Since your timing will be retarded, your power will be decreased.
Since your EGR will no longer be keeping detonation down, your engine will detonate more (destructive)."
I'm still pretty sold on deleting EGR (keeping knock sensor) because the corvette fever article on TBI swap made no mention of EGR (but did list the knock sensor as a required part) and said they had a custom chip burned. It's the same swap that I'm doing.
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Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Originally Posted by 1982CorvetteDude
Since your timing will be retarded, your power will be decreased.
Since your EGR will no longer be keeping detonation down, your engine will detonate more (destructive)."[/B]
I'm still pretty sold on deleting EGR (keeping knock sensor) because the corvette fever article on TBI swap made no mention of EGR (but did list the knock sensor as a required part) and said they had a custom chip burned. It's the same swap that I'm doing.
Since your EGR will no longer be keeping detonation down, your engine will detonate more (destructive)."[/B]
I'm still pretty sold on deleting EGR (keeping knock sensor) because the corvette fever article on TBI swap made no mention of EGR (but did list the knock sensor as a required part) and said they had a custom chip burned. It's the same swap that I'm doing.
Who's gonna burn your chip? Those guys usually know there stuff, and will gladly answer your questions.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
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From: Arkansas
Originally Posted by Durango_boy
Who's gonna burn your chip? Those guys usually know there stuff, and will gladly answer your questions.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by 1982CorvetteDude
Haven't found a source yet.....I'll def do that.
I'll try to remember when I get home, and I'll post the guy that's gonna do mine. Good prices, and they can do chips for custom engines with unique bore and cam specs.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
knock sensor is key player in ecm spark control...do not leave home without it...maF type TPI (-165 ecm) and maP type (-730/-727ecm) use DIFFERENT knock sensors and do not interchange...
egr can be deleted but engine will run ''warm'' in part throttle driving conditions and mil will be activated in some ecm applications after driving at constant (medium) vehicle speed for programmed time period...the mil will NOT stay on at the next start-up, but code will be stored in memory, and mil will return in next constant drive situation...there are ways to ''fool'' the ecm when egr is deleted, but its simpler to simply hook it up--many aftermarket chips delete egr and modify fuel/spark curves accordingly--stock chips will work fine for most installations
btw, you can run with only CTS, TPS, and distrib signals to the ecm, some street rods do that...but it only runs like a carb set-up would, none of the self-tuning that the ecm is ready to give.
egr can be deleted but engine will run ''warm'' in part throttle driving conditions and mil will be activated in some ecm applications after driving at constant (medium) vehicle speed for programmed time period...the mil will NOT stay on at the next start-up, but code will be stored in memory, and mil will return in next constant drive situation...there are ways to ''fool'' the ecm when egr is deleted, but its simpler to simply hook it up--many aftermarket chips delete egr and modify fuel/spark curves accordingly--stock chips will work fine for most installations
btw, you can run with only CTS, TPS, and distrib signals to the ecm, some street rods do that...but it only runs like a carb set-up would, none of the self-tuning that the ecm is ready to give.
Last edited by redrose; Dec 11, 2006 at 03:33 PM.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
Likes: 2
From: Arkansas
Originally Posted by redrose
knock sensor is key player in ecm spark control...do not leave home without it...maF type TPI (-165 ecm) and maP type (-730/-727ecm) use DIFFERENT knock sensors and do not interchange...
egr can be deleted but engine will run ''warm'' in part throttle driving conditions and mil will be activated in some ecm applications after driving at constant (medium) vehicle speed for programmed time period...the mil will NOT stay on at the next start-up, but code will be stored in memory, and mil will return in next constant drive situation...there are ways to ''fool'' the ecm when egr is deleted, but its simpler to simply hook it up--many aftermarket chips delete egr and modify fuel/spark curves accordingly--stock chips will work fine for most installations
btw, you can run with only CTS, TPS, and distrib signals to the ecm, some street rods do that...but it only runs like a carb set-up would, none of the self-tuning that the ecm is ready to give.
egr can be deleted but engine will run ''warm'' in part throttle driving conditions and mil will be activated in some ecm applications after driving at constant (medium) vehicle speed for programmed time period...the mil will NOT stay on at the next start-up, but code will be stored in memory, and mil will return in next constant drive situation...there are ways to ''fool'' the ecm when egr is deleted, but its simpler to simply hook it up--many aftermarket chips delete egr and modify fuel/spark curves accordingly--stock chips will work fine for most installations
btw, you can run with only CTS, TPS, and distrib signals to the ecm, some street rods do that...but it only runs like a carb set-up would, none of the self-tuning that the ecm is ready to give.
Thanks for the input
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Originally Posted by 1982CorvetteDude
So basically I could get a modified chip and delete egr w/o hurting anything? That would be easiest for me because I would still have to buy a egr solenoid and hook all that up. As long as it doesn't hurt the engine and it will still run I'm... ok with just getting a custom chip with the fuel/ spark curves modified.
Thanks for the input
Thanks for the input
Here's the guy doing my harness and custom chip. Give him a call, his name is Dana.
LT1 Wiring
2737 E 44th St.
Erie, PA 16510
814-323-3021
Dana Dash
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Howell and Street & Performance can burn TBI proms I believe. On OBD2 I would believe more of "have to have the whole car so as not to have a constant SES light" but not OBD1. The PROM flash experts can turn off the things you don't want, like EGR. I would leave canister purge, but some remove it too. VATS is not an issue on TBI cars. I have 30k miles on the TPI swap in my pickup. SES light has never come on. I had VATS and EGR deleted, kept canister purge.
For my money, I would go TPI before TBI. TPI stuff is cheap now. The only difference in installation money is the intake; you still need custom PROM, fuel pump, harness, ECM, high pressure fuel line, etc.
For my money, I would go TPI before TBI. TPI stuff is cheap now. The only difference in installation money is the intake; you still need custom PROM, fuel pump, harness, ECM, high pressure fuel line, etc.
Thread Starter
Melting Slicks
Joined: Jun 2005
Posts: 2,938
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From: Arkansas
The problem I have with buying used stuff (on TPI) is that you don't know what your going to get. Finding a good clean unit for a decent price is hard to find. Most I have seen end up being someone elese junk.
I'm keeping a watch out though....maybe I'll luck out and find a good clean set-up and switch to TPI.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
You missed it man. A few months ago I sold a complete Speed Density TPI setup, complete with EVERYTHING I would have needed to put it in my '77 Vette, including a custom harness. I sold it all on Ebay for about $400, and I had it in a for sale add in the parts section. Shame you didn't see that one...it was clean and prepped for install.
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
For $175 I have an 85 'Vette unit. Fair/poor runners. Would probably have to have injectors. Fuel rail lines were cut just at the connector (I have it). New gaskets, super clean, stainless bolts.
Either one would be: intake base, pair of runners, plenum, throttle body, rear extension, fuel rail, injectors, and a small-cap distributor. No 9th injector with either one. Can send photos of either if interested.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I have an 88 'Vette TPI, real nice runners. Been sitting a few years now, but inside. Taken apart and cleaned. Like to get $350 for it.
For $175 I have an 85 'Vette unit. Fair/poor runners. Would probably have to have injectors. Fuel rail lines were cut just at the connector (I have it). New gaskets, super clean, stainless bolts.
Either one would be: intake base, pair of runners, plenum, throttle body, rear extension, fuel rail, injectors, and a small-cap distributor. No 9th injector with either one. Can send photos of either if interested.
For $175 I have an 85 'Vette unit. Fair/poor runners. Would probably have to have injectors. Fuel rail lines were cut just at the connector (I have it). New gaskets, super clean, stainless bolts.
Either one would be: intake base, pair of runners, plenum, throttle body, rear extension, fuel rail, injectors, and a small-cap distributor. No 9th injector with either one. Can send photos of either if interested.
Both of those are MAF? Was '92 the only Speed Density year or was that '93 too?
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
and any lt1 intake will run with a maF sensor in front of it.
gotta use the matching ecm/prom
Last edited by redrose; Dec 12, 2006 at 11:15 PM.