NEW ENGINE, trying to breakin, SURGING
Thread Starter
Pro
Joined: Mar 2004
Posts: 508
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From: N.W. CT
NEW ENGINE, trying to breakin, SURGING
1990, 388, 9:1 comp, AFR 195s ,Comp 280xfi, superram,30lbs, 58mm t/b, no emissions or egr, pcmforless chip.
I got it running and changed the oil, it is idling at 1,100 rpm. It stalls sometimes when idling. It also smell like it is running rich, and it is backfiring once in a while when idling and on deceleration.
When I took it for a ride to set the rings I gave it half throttle and it would surge badly from 2000 rpm and up. The check engine light is also on. At about a 1/8 throttle it wont surge.
It is throwing a code 24, 14
Also it will not surge when I rev it up in neutral.
I only drove it around the block, I dont want to continue driving it and ruin the engine.
Any advice you can give would help, I have spent everyday for over a year on this build. Thanks
I got it running and changed the oil, it is idling at 1,100 rpm. It stalls sometimes when idling. It also smell like it is running rich, and it is backfiring once in a while when idling and on deceleration.
When I took it for a ride to set the rings I gave it half throttle and it would surge badly from 2000 rpm and up. The check engine light is also on. At about a 1/8 throttle it wont surge.
It is throwing a code 24, 14
Also it will not surge when I rev it up in neutral.
I only drove it around the block, I dont want to continue driving it and ruin the engine.
Any advice you can give would help, I have spent everyday for over a year on this build. Thanks
Last edited by Doughboy2k3; Feb 20, 2011 at 06:19 PM.
Burning Brakes
Joined: Feb 2010
Posts: 1,013
Likes: 2
From: California City Ca
I feel for you I am still trying to get my rebuild 100%.
First make sure you have no vacume leaks My end up beening a pice of tape that got stuck between the intake base and the runners was where my leaked.
I had Issues with the Idle Air Control Valve (IACV) Could not get the car to Idle change this out much better.
I also have full lenght headers I had to go with a heated O2 sender the 1 wire was not getting hot enought.
For me one step at a time I almost there my self.
First make sure you have no vacume leaks My end up beening a pice of tape that got stuck between the intake base and the runners was where my leaked.
I had Issues with the Idle Air Control Valve (IACV) Could not get the car to Idle change this out much better.
I also have full lenght headers I had to go with a heated O2 sender the 1 wire was not getting hot enought.
For me one step at a time I almost there my self.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
Likes: 5
If any or all 8 spark plugs are fouled out,
You will go crazy trying to find out whats wrong yet and retune your engine.
Speak from experience years ago when younger in my 20's.
There is a reason why a spark plug(s) fouled out if that has happened.
BR
You will go crazy trying to find out whats wrong yet and retune your engine.
Speak from experience years ago when younger in my 20's.
There is a reason why a spark plug(s) fouled out if that has happened.
BR
Race Director
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Thread Starter
Pro
Joined: Mar 2004
Posts: 508
Likes: 0
From: N.W. CT
I also check my wires and they are good. My timing is also set to 6 with the timing wire pulled.
I removed my plugs and they are very fouled. Perhaps as a result of all of the oil I coated the cyl with prior to installing the heads. I just purchased new plugs a hour ago.
I found the breather hose going from the valve cover into the t/b was very loose perhaps causing a leak. I will cut it back and make sure it is secure.
Thank you for all of the replies so far. And any other replies will be greatly appreciated. Thanks Walt
Last edited by Doughboy2k3; Feb 20, 2011 at 09:22 PM.
Thread Starter
Pro
Joined: Mar 2004
Posts: 508
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From: N.W. CT
I have not had a chance to start it yet. It is pretty loud and I have to wait for the daytime.
I found out my 90 does not have a adjustable tps. I am unable to get it above .41 closed and 3.45 at wot. I have tried two seperate tps's with the same result. Is this normal? Thanks for the replies.
I found out my 90 does not have a adjustable tps. I am unable to get it above .41 closed and 3.45 at wot. I have tried two seperate tps's with the same result. Is this normal? Thanks for the replies.
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
no it's not normal...first what is the idle rpm in the tune? Get it to operating temp. set the IAC counts to +/-40, and recheck base timing to 6*. I would also be looking for any vacuum leaks. If it is still that rich then probably the 02 is fouled out by now, the tune needs to be worked more, and it will run poorly.
Thread Starter
Pro
Joined: Mar 2004
Posts: 508
Likes: 0
From: N.W. CT
no it's not normal...first what is the idle rpm in the tune? Get it to operating temp. set the IAC counts to +/-40, and recheck base timing to 6*. I would also be looking for any vacuum leaks. If it is still that rich then probably the 02 is fouled out by now, the tune needs to be worked more, and it will run poorly.
The car runs so rich I cant get it to idle with the iac disconnected.
I replaced the CTS and I still keep throwing a code 14 as soon as it fires. Code 14 is (high temp indicated) on the coolant temp sensor (cts).
Do you think if the car believed it was overheating it would go into limp mode causing it to run so rich?
Le Mans Master
Joined: Feb 2005
Posts: 5,146
Likes: 3
From: The Motor City
I replaced the CTS and I still keep throwing a code 14 as soon as it fires. Code 14 is (high temp indicated) on the coolant temp sensor (cts). Do you think if the car believed it was overheating it would go into limp mode causing it to run so rich?
I would also look at the 02 mv. on the data master after the car enters closed loop. If you see the m.volts saying the same with little or no cross counts, that will indicate a trashed 02 sensor and also cause the car to be excessively rich. Typically if the tune were rich to begin with, it will trash an 02 sensor.
Last edited by mseven; Feb 22, 2011 at 06:27 PM.
Pro
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From: Plano, TX
Last edited by 93VettePilot; Feb 23, 2011 at 10:47 AM.
Le Mans Master
Joined: Mar 2002
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From: Castro Valley Calif.
St. Jude Donor '03 thru '26
Hey Walt, it's good to hear you've got it together and running now, hang in there & you'll get sorted out! I agree w/Mick, I had a bad O2 and my car wouldn't run worth a damn no matter what I did. Are you logging? If so the cross counts will tell the story.....no matter what you do it won't smooth out with a bad O2. Congrats brotha stay the course, your getting close 