Quick question - Glowing manifold, low speed
Quick question - Glowing manifold, low speed Helping a friend finish up his swap
Fired the car and got it going alright. Drove it up and down the road and the manifold is flat out glow-in-the dark. Id expect this to be normal for WOT bursts and other drive-like-an-idiot conditions, but not casual drive like a gramma up and down the road. It's enough to severely heatsoak the charge pipe post-intercooler from about 8" away
What causes this? My best guess so far is excessive rich condition from untuned bigger injectors or the turbo is flat worn out
All cyls are firing properly, not sure how ridiculous the IATs are getting. Havent picked up or heard anything relating to pinging or knock so I doubt its a lean condition
Darn thing sounds like a diesel
Fired the car and got it going alright. Drove it up and down the road and the manifold is flat out glow-in-the dark. Id expect this to be normal for WOT bursts and other drive-like-an-idiot conditions, but not casual drive like a gramma up and down the road. It's enough to severely heatsoak the charge pipe post-intercooler from about 8" away
What causes this? My best guess so far is excessive rich condition from untuned bigger injectors or the turbo is flat worn out
All cyls are firing properly, not sure how ridiculous the IATs are getting. Havent picked up or heard anything relating to pinging or knock so I doubt its a lean condition
Darn thing sounds like a diesel
Problem is bolded, you should never be running a larger injector without compensating for it in the tune, for any reason, unless you want to get rid of your motor.
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Verdad Gallardo 2.0L Sunbird engine with a T2 (tiny)
24# are huge for it and well needed with the addition of an intercooler and the boost turned up from 7psi to 20
Power compared to LSx is dismal at best, but it's his engine. I just wanted a base to start troubleshooting it and I got it. Thanks
24# are huge for it and well needed with the addition of an intercooler and the boost turned up from 7psi to 20
Power compared to LSx is dismal at best, but it's his engine. I just wanted a base to start troubleshooting it and I got it. Thanks
Teching In
Joined: Apr 2010
Posts: 17
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Does it have a hot cam? Unburnt air/fuel could be blowing through during overlap, odd because it usually happens the other way round. Running rich is not going to heat up the manifolds, the fuel has no air to burn in the manifold. I would guess it is lean or advanced timing.
Wait, sounds like a diesel? That is your timing.
Wait, sounds like a diesel? That is your timing.
Registered User
Joined: Sep 2010
Posts: 3
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I just found both this thread and my allusive timing light. So, I'll clear this up. I cranked the engine without shorting the diagnostics terminal; the car started right up and idled at 8*BTDC +- 1*, right where it should be. I shorted the diagnostic terminal and tried cranking the car again. The engine would putter up to about 500 and die after running for about a second. I had to give it a little gas to keep it running. Got the light on the pulley and couldn't find the mark. It's clocked about 90* advance - problem solved.
I did the oil pump on this engine, which required me to pull the timing belt and reinstall it. Pocket lives about 30 minutes from me, so I was trying to get the car home before dark and didn't reset ignition timing. I suppose it's worth mentioning that the car is a 1986 Fiero. I've been rebuilding the 2.0 Turbo Grand Am engine at Pocket's house. Anyway, 30 seconds out of his driveway, I turned around to look through the rear bulkhead (between the seats) at the engine. The exhaust mani was glowing bright orange. It wasn't just a low glow, it looked like this:
Anyway, it scared me enough to merit pulling over. I know the mani should be getting hot, but certainly not glowing orange at 30mph. I'll wait for the sun to come up a little bit more and go set the timing. I made it brief earlier, I didn't want any of my neighbors coming out with a 12 gauge for cranking a open downpipe turbo car at 7am Sunday morning.
I did the oil pump on this engine, which required me to pull the timing belt and reinstall it. Pocket lives about 30 minutes from me, so I was trying to get the car home before dark and didn't reset ignition timing. I suppose it's worth mentioning that the car is a 1986 Fiero. I've been rebuilding the 2.0 Turbo Grand Am engine at Pocket's house. Anyway, 30 seconds out of his driveway, I turned around to look through the rear bulkhead (between the seats) at the engine. The exhaust mani was glowing bright orange. It wasn't just a low glow, it looked like this:
Anyway, it scared me enough to merit pulling over. I know the mani should be getting hot, but certainly not glowing orange at 30mph. I'll wait for the sun to come up a little bit more and go set the timing. I made it brief earlier, I didn't want any of my neighbors coming out with a 12 gauge for cranking a open downpipe turbo car at 7am Sunday morning.
glowing hot When mine did it, I had too small of a turbine housing on my truck. I had a cheap Holset H2D with 19mm housing on my truck with sbc 350.
I changed turbos and got a mpt70, and had no more problems.
Let your car idle, take off a piece of inlet tubing that runs from the turbo to the motor (doesn't matter which piece, ANY piece)....with car idleing, feel how much air flow you have comming from turbo.
It should be minimal,very minimal. If you have a good bit, then your turbo is too small. Mine felt almost like a hair dryer was running on a low setting. Neeedless to say, if I drove it down the road, hard driving or not, it would glow red just as what you are describing, and once it started glowing, no matter at idle or not, the exhaust gas couldn't get out, it would glow red all the time.
Just my experience
I changed turbos and got a mpt70, and had no more problems.
Let your car idle, take off a piece of inlet tubing that runs from the turbo to the motor (doesn't matter which piece, ANY piece)....with car idleing, feel how much air flow you have comming from turbo.
It should be minimal,very minimal. If you have a good bit, then your turbo is too small. Mine felt almost like a hair dryer was running on a low setting. Neeedless to say, if I drove it down the road, hard driving or not, it would glow red just as what you are describing, and once it started glowing, no matter at idle or not, the exhaust gas couldn't get out, it would glow red all the time.
Just my experience
Registered User
Joined: Sep 2010
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Regarding the larger injectors, there was a bit of confusion; I never installed any, the injectors are OEM. In any other application, to command more boost, we'd most likely have to up the injector size or increase the duty cycle. Gm's older line of turbo engines were never engineered to take advantage of an intercooler, and so GM circa 1990 programmed the injectors to dump raw fuel to keep charge temperatures down. One owner on the J-body forum has reported being able to cut the original duty cycle by almost half with the addition of an efficient a-a intercooler. I'm hoping to be able to trim the fuel a good amount once I get all the bugs sorted out of the system.
The engine makes more power and torque than the standard V6, is a great deal lighter, and hopefully won't be that thirsty after trimming the fuel. Although, it's been a royal PITA for Pocket and I given my limited budget and use of Volvo charge pipe couplers. xD
Makes sense, thanks for sharing! The turbo is the stock Garret T25 (not T2), I'm hoping the timing was responsible and the turbo doesn't need to be rebuilt.
next guess My next guess would be timing too retarded, making the gas complete the burn in the manifolds, causing the superheated condition, and also combine that with extra fuel, then that's more heat.
Is there a way to bleed off some fuel pressure while it's running, so see if the glow goes away? (cut down on fuel psi) Adjustible fuel pressure regulator? Maybe a fuel pressure schrader valve that we can put a gauge on, release some pressure that way?
can you advance the timing to see if that helps?
Lets see what happens!
Is there a way to bleed off some fuel pressure while it's running, so see if the glow goes away? (cut down on fuel psi) Adjustible fuel pressure regulator? Maybe a fuel pressure schrader valve that we can put a gauge on, release some pressure that way?
can you advance the timing to see if that helps?
Lets see what happens!
