88reatt Posted January 3, 2023 Share Posted January 3, 2023 Recently picked up a Reatta with issues, has been sitting since 2014. Found out it had no spark and the fuel system was bad. I replaced the crank position sensor, icm, and the coil. I also completely revamped the fuel system. I now have both fuel and spark, but the car backfires out of the exhaust and intake. I have doubled checked the icm wiring, and the spark plug wiring, and I have removed the valve covers to make sure all the valves were moving correctly. Hoping some sees this because I really need to get it going, thanks! Link to comment Share on other sites More sharing options...
3macboys Posted January 3, 2023 Share Posted January 3, 2023 8 minutes ago, 88reatt said: Recently picked up a Reatta with issues, has been sitting since 2014. Found out it had no spark and the fuel system was bad. I replaced the crank position sensor, icm, and the coil. I also completely revamped the fuel system. I now have both fuel and spark, but the car backfires out of the exhaust and intake. I have doubled checked the icm wiring, and the spark plug wiring, and I have removed the valve covers to make sure all the valves were moving correctly. Hoping some sees this because I really need to get it going, thanks! Scroll down on the main Forum page and you will find an area dedicated to Buicks and then a subgroup for Reattas. Post there as well, they are quite active, and hopefully you get the assistance you need. 1 Link to comment Share on other sites More sharing options...
EmTee Posted January 4, 2023 Share Posted January 4, 2023 Sounds like valves are sticking. 1 Link to comment Share on other sites More sharing options...
88reatt Posted January 4, 2023 Author Share Posted January 4, 2023 1 hour ago, EmTee said: Sounds like valves are sticking. I checked the valve train and it seemed to be moving in correct order, I’m going to test the injectors this week to make sure their not stuck open or anything. If they are not, it’s most definitely a valve train problem. Link to comment Share on other sites More sharing options...
2seater Posted January 4, 2023 Share Posted January 4, 2023 You didn't mention what year Reatta, but do you know how to access the onboard diagnostics? Is the check engine light on?? Is the ICM and coil pack new or salvage yard and is it the correct package? I know that may be a silly question but there are similar setups for some other GM V6's that may not function correctly. Link to comment Share on other sites More sharing options...
EmTee Posted January 4, 2023 Share Posted January 4, 2023 Backfiring through the intake indicates valve(s) open that should be closed. This can happen if either the ignition timing or valve timing is off. Or, the valve is sticking in the guide and not closing completely despite the spring pressure. 1 Link to comment Share on other sites More sharing options...
Ronnie Posted January 4, 2023 Share Posted January 4, 2023 On 1/2/2023 at 9:19 PM, 88reatt said: the car backfires out of the exhaust and intake. I have doubled checked the icm wiring, and the spark plug wiring, Odds of a intake and exhaust valve sticking at the same time are pretty slim. It sounds like it is firing out of time. Not likely the Crank Sensor would cause it to be out of time unless the metal ring on the harmonic balancer has hit the sensor. I would check the plug wires and the wires running between the ICM and coil pack carefully again. This looks bad but you can tell from looking at it how the wires should connect. 1 Link to comment Share on other sites More sharing options...
EmTee Posted January 4, 2023 Share Posted January 4, 2023 1 minute ago, Ronnie said: Odds of a intake and exhaust valve sticking at the same time are pretty slim. This doesn't have to be on the same cylinder. Intake and exhaust valves can be randomly sticking on different cylinders at different times. It was stated that the car had been sitting since 2014. Was the gas tank drained and refilled with fresh gas before attempting to start the engine? If this car was run with old gas, that can cause valves to stick in their guides. If that's the case and it gets bad enough, the result can be bent pushrods... 2 Link to comment Share on other sites More sharing options...
Ronnie Posted January 4, 2023 Share Posted January 4, 2023 It will interesting to find out what fixes it. Link to comment Share on other sites More sharing options...
padgett Posted January 4, 2023 Share Posted January 4, 2023 88 onboard diagnostics include a way to identify which cyl is misfiring. See section 8D in the factory service manual. 2 Link to comment Share on other sites More sharing options...
88reatt Posted January 4, 2023 Author Share Posted January 4, 2023 1 hour ago, EmTee said: This doesn't have to be on the same cylinder. Intake and exhaust valves can be randomly sticking on different cylinders at different times. It was stated that the car had been sitting since 2014. Was the gas tank drained and refilled with fresh gas before attempting to start the engine? If this car was run with old gas, that can cause valves to stick in their guides. If that's the case and it gets bad enough, the result can be bent pushrods... When I got the car the 8 year old gas had already destroyed the fuel pump so it didn’t pump any gas until I redid the fuel system 1 Link to comment Share on other sites More sharing options...
88reatt Posted January 4, 2023 Author Share Posted January 4, 2023 1 hour ago, padgett said: 88 onboard diagnostics include a way to identify which cyl is misfiring. See section 8D in the factory service manual. Unfortunately the screens are having trouble displaying, still figuring it out. Although, the abs light is on but that’s normal. Link to comment Share on other sites More sharing options...
88reatt Posted January 4, 2023 Author Share Posted January 4, 2023 1 hour ago, 2seater said: You didn't mention what year Reatta, but do you know how to access the onboard diagnostics? Is the check engine light on?? Is the ICM and coil pack new or salvage yard and is it the correct package? I know that may be a silly question but there are similar setups for some other GM V6's that may not function correctly. It is an 88, I believe I mentioned it in the title. Link to comment Share on other sites More sharing options...
padgett Posted January 4, 2023 Share Posted January 4, 2023 Well the alternative to the CRT is either a ALDL >USB dongle and TunerPro RT Windows software or an OTC 2000 scan tool (ebay) with a late GM cartridge and ALDL cable. 1 Link to comment Share on other sites More sharing options...
arcticbuicks Posted January 5, 2023 Share Posted January 5, 2023 sure sounds like a bad module under the coil pack Link to comment Share on other sites More sharing options...
2seater Posted January 5, 2023 Share Posted January 5, 2023 Correction to previous; yes the year is in the title😞 This sounds similar to what happened with Daves, ironically also an 88, when the crank sensor was loose in the bracket. Terrible behavior but not a constant. 1 Link to comment Share on other sites More sharing options...
88reatt Posted January 5, 2023 Author Share Posted January 5, 2023 8 hours ago, padgett said: Well the alternative to the CRT is either a ALDL >USB dongle and TunerPro RT Windows software or an OTC 2000 scan tool (ebay) with a late GM cartridge and ALDL cable. I talked to the owner of east coast reattas and found out it’s most likely the central power supply causing problems. 1 Link to comment Share on other sites More sharing options...
padgett Posted January 5, 2023 Share Posted January 5, 2023 Central power supply can cause CRT problems but never heard of it affecting running. Think you are seeing multiple issues, probably need to fix comm first. BTW nice thing about TunerPro RT is can display many things at once. Link to comment Share on other sites More sharing options...
88reatt Posted January 6, 2023 Author Share Posted January 6, 2023 19 hours ago, padgett said: Central power supply can cause CRT problems but never heard of it affecting running. Think you are seeing multiple issues, probably need to fix comm first. BTW nice thing about TunerPro RT is can display many things at once. I was just mentioning that my new crt I bought is stuck on the radio screen and the dash comes on and off intermittently and it’s most definitely the central power supply causing the problem. Link to comment Share on other sites More sharing options...
Ronnie Posted January 6, 2023 Share Posted January 6, 2023 56 minutes ago, 88reatt said: I was just mentioning that my new crt I bought is stuck on the radio screen and the dash comes on and off intermittently and it’s most definitely the central power supply causing the problem. I think RAP is your problem. I doubt a CPS will fix it. Check out this How-to Guide: CRT Does Not Light Up But Radio Plays Link to comment Share on other sites More sharing options...
88reatt Posted January 6, 2023 Author Share Posted January 6, 2023 28 minutes ago, Ronnie said: I think RAP is your problem. I doubt a CPS will fix it. Check out this How-to Guide: CRT Does Not Light Up But Radio Plays I’m not for sure if that’s the problem because a lot of that stuff works and the crt displays the radio screen all the time, but the gauge cluster comes on very rarely Link to comment Share on other sites More sharing options...
padgett Posted January 6, 2023 Share Posted January 6, 2023 Bad CPS will keep the CRT from lighting. Keep in mind that the display is two separate devices: the buttons and touchscream are one and the CRT is another. Sounds like a button problem. ps is also a CRTC. Link to comment Share on other sites More sharing options...
88reatt Posted March 6 Author Share Posted March 6 Yeah I know this was a long time ago, but it ending just being really bad spark plugs. Link to comment Share on other sites More sharing options...
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