82 crossfire intermittent hesitation
10-24-2016, 10:38 AM
#1
1st Gear
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82 crossfire intermittent hesitation
Hello, Need some help with my 1982 crossfire fuel injection. WOT the car runs great.
Sit at a stop light the car idles ok, but then hesitates and can die if you do not know how to play with the throttle.
The throttle bodies look very clean so I do not think it is a fuel grade issue, but maybe a fuel pressure issue.
I was reading other forums/threads about the fuel pressure regulator needing to be adjusted, but with various threads and misinformation I decided to start my own thread to get an area where to start.
I have not checked fuel pressure, but I did take the air cleaner off and watch the injector spray and it looks like the right bank injector maybe an issue.
I add throttle the injectors spray a nice healthy flow of fuel.
I left off the throttle and the drivers side injector keeps a good uniform cone spray going on, but the passenger side injector looks like it doesn't spray as nicely almost like the pressure is dropping or something on that side.
Trying to get this car all buttoned away for the season as it is getting cold here in Michigan. The 81 we have runs great and with talking to many people they pull the crossfire to put back to carb, but I will not do that with this car as it only has 28,000 miles.
There look to be many people that stand by the crossfire so I am hoping one of these die hards can help
Thank you for the help guys.
Sit at a stop light the car idles ok, but then hesitates and can die if you do not know how to play with the throttle.
The throttle bodies look very clean so I do not think it is a fuel grade issue, but maybe a fuel pressure issue.
I was reading other forums/threads about the fuel pressure regulator needing to be adjusted, but with various threads and misinformation I decided to start my own thread to get an area where to start.
I have not checked fuel pressure, but I did take the air cleaner off and watch the injector spray and it looks like the right bank injector maybe an issue.
I add throttle the injectors spray a nice healthy flow of fuel.
I left off the throttle and the drivers side injector keeps a good uniform cone spray going on, but the passenger side injector looks like it doesn't spray as nicely almost like the pressure is dropping or something on that side.
Trying to get this car all buttoned away for the season as it is getting cold here in Michigan. The 81 we have runs great and with talking to many people they pull the crossfire to put back to carb, but I will not do that with this car as it only has 28,000 miles.
There look to be many people that stand by the crossfire so I am hoping one of these die hards can help
Thank you for the help guys.
10-24-2016, 11:57 AM
#2
Melting Slicks
Hello, Need some help with my 1982 crossfire fuel injection. WOT the car runs great.
Sit at a stop light the car idles ok, but then hesitates and can die if you do not know how to play with the throttle.
The throttle bodies look very clean so I do not think it is a fuel grade issue, but maybe a fuel pressure issue.
I was reading other forums/threads about the fuel pressure regulator needing to be adjusted, but with various threads and misinformation I decided to start my own thread to get an area where to start.
I have not checked fuel pressure, but I did take the air cleaner off and watch the injector spray and it looks like the right bank injector maybe an issue.
I add throttle the injectors spray a nice healthy flow of fuel.
I left off the throttle and the drivers side injector keeps a good uniform cone spray going on, but the passenger side injector looks like it doesn't spray as nicely almost like the pressure is dropping or something on that side.
Trying to get this car all buttoned away for the season as it is getting cold here in Michigan. The 81 we have runs great and with talking to many people they pull the crossfire to put back to carb, but I will not do that with this car as it only has 28,000 miles.
There look to be many people that stand by the crossfire so I am hoping one of these die hards can help
Thank you for the help guys.
Sit at a stop light the car idles ok, but then hesitates and can die if you do not know how to play with the throttle.
The throttle bodies look very clean so I do not think it is a fuel grade issue, but maybe a fuel pressure issue.
I was reading other forums/threads about the fuel pressure regulator needing to be adjusted, but with various threads and misinformation I decided to start my own thread to get an area where to start.
I have not checked fuel pressure, but I did take the air cleaner off and watch the injector spray and it looks like the right bank injector maybe an issue.
I add throttle the injectors spray a nice healthy flow of fuel.
I left off the throttle and the drivers side injector keeps a good uniform cone spray going on, but the passenger side injector looks like it doesn't spray as nicely almost like the pressure is dropping or something on that side.
Trying to get this car all buttoned away for the season as it is getting cold here in Michigan. The 81 we have runs great and with talking to many people they pull the crossfire to put back to carb, but I will not do that with this car as it only has 28,000 miles.
There look to be many people that stand by the crossfire so I am hoping one of these die hards can help
Thank you for the help guys.
Now on to you r issue. CFI is very finicky about fuel pressure and that may be an issue, but since you say it runs OK at WOT that may not be the issue. One question, does the motor seem to roll on over on its face around or after 4,200RPM at WOT? If so, it is more than likely the pressure is either too low or the pump is weak or both. Set the FP at 13psi via the rear TB FPR measured in-between both TBs.
Next, it could be an issue with the TPS sensor not being set properly or is bad all together. The TPS MUST be set properly so the ECM knows where idle is in relation to the throttle blade angle. Set it at .525v, key ON, engine OFF.
Lastly, most CF owners that go to a carb is because they DO NOT understand how it works or how to maintain a CF or jack it up enough that it becomes a serious PITA and call it a POS and end up junking it.
IMO, if someone is serious about getting rid of the CF, I would go EFI before putting a carb on the engine, more advantages in doing that than disadvantages.
Try the things mentioned and see what you come up with a post back your results and go from there.
BTW: Everything mentioned, FP and TPS setting is in the manual.
Last edited by Buccaneer; 10-26-2016 at 06:45 PM.
10-24-2016, 06:43 PM
#3
Race Director
First things first...I can't say this enough, purchase a GM service manual for a car that is over 30 years old, it's a MUST to keep it running well.
Now on to you r issue. CFI is very finicky about fuel pressure and that may be an issue, but since you say it runs OK at WOT that may not be the issue. One question, does the motor seem to roll on over on its face around or after 4,200RPM at WOT? If so, it is more than likely the pressure is either too low or the pump is weak or both. Set the FP at 13psi via the rear TB FPR measured in-between both TBs.
Next, it could be an issue with the TPS sensor not being set properly or is bad all together. The TPS MUST be set properly so the ECM knows where idle is in relation to the throttle blade angle. Set it at .525v, key ON, engine OFF.
Lastly, most CF owners that go to a carb is because they DO NOT understand how it works or how to maintain a CF or jack it up enough that it becomes a serious PITA and call it a POS and end up junking it.
IMO, if someone is serious about getting rid of the CF, I would go EFI before putting a carb on the engine, most advantages in doing that than disadvantages.
Try the things mentioned and see what you come up with a post back your results and go from there. BTW: Everything mentioned, FP and TPS setting is in the manual.
Now on to you r issue. CFI is very finicky about fuel pressure and that may be an issue, but since you say it runs OK at WOT that may not be the issue. One question, does the motor seem to roll on over on its face around or after 4,200RPM at WOT? If so, it is more than likely the pressure is either too low or the pump is weak or both. Set the FP at 13psi via the rear TB FPR measured in-between both TBs.
Next, it could be an issue with the TPS sensor not being set properly or is bad all together. The TPS MUST be set properly so the ECM knows where idle is in relation to the throttle blade angle. Set it at .525v, key ON, engine OFF.
Lastly, most CF owners that go to a carb is because they DO NOT understand how it works or how to maintain a CF or jack it up enough that it becomes a serious PITA and call it a POS and end up junking it.
IMO, if someone is serious about getting rid of the CF, I would go EFI before putting a carb on the engine, most advantages in doing that than disadvantages.
Try the things mentioned and see what you come up with a post back your results and go from there.
BTW: Everything mentioned, FP and TPS setting is in the manual.
X2.And if you do not have anyone who KNOWS how to work on this engine. I would highly advise you in getting a scanner so you can read the data when the engine is running. Attempting to fix this with a 'pair of pliers and a hammer' mentality is just not going to happen. Because just being able to set-up and be able to read the fuel pressure can make most people stop and give up.
DUB
Last edited by DUB; 10-24-2016 at 06:44 PM.
10-24-2016, 09:20 PM
#4
Le Mans Master
I would start with checking for fuel pressure at the fuel filter.its easy to check there .you should check it between the tbs.if it is below 13- 14 psi then the fuel pump is plugged or bad. the fuel pumps on these cars are not very good.the fix is one from a 1985 to 1987 corvette.If you find the pump is good then your right bank injector is bad or dirty.
10-26-2016, 10:33 AM
#5
Safety Car
If it pops or bogs off the start, the first thing I would do is add a few degrees of timing. Even if the timing mark is dead on, add 3 degrees. If that doesn't help, follow the steps posted above.
The CFI is extremely reliable once the plenum gasket is replaced, a few degrees of timing added, fuel pressure checked and the TPS set. I've been running mine for over 10 years and 30,000 miles without 1 problem. The car now has 140,000 on the original engine. So many people mess up the CFI and then get frustrated. Even GM let these cars roll out with vac leaks, mis adjusted TPS, throttle blades unequal, timing to far retarded and weak fuel pressure but get everything dialed in, it will run 100,000 without needing to be touched.
It's not hard once you understand the system, good luck
The CFI is extremely reliable once the plenum gasket is replaced, a few degrees of timing added, fuel pressure checked and the TPS set. I've been running mine for over 10 years and 30,000 miles without 1 problem. The car now has 140,000 on the original engine. So many people mess up the CFI and then get frustrated. Even GM let these cars roll out with vac leaks, mis adjusted TPS, throttle blades unequal, timing to far retarded and weak fuel pressure but get everything dialed in, it will run 100,000 without needing to be touched.
It's not hard once you understand the system, good luck
10-26-2016, 07:39 PM
#6
Zen Vet Master Level VII
Your problems don't sound complicated enough to consider scrapping the CFI. Frankly, once you get your CFI dialed in, you really wont want to go back to a carb.