Rough running fresh engine start

[Bob Davi]

Hello,

Just got one of our engine rebuild projetcs started tonight. Good oil pressure and quiet running, BUT....I have to pump the pedal to keep it running..it won't run if I let off pedal or hold pedal steady. It's also backfiring slightly once in a while. Reminds me of a carb'd car with a huge vacuum leak, like you left vacuum plug out of manifold under carb, but we can't find any large holes.

Injectors have been sitting in the shop for about two years; worked fine last time they were in the car, but I thought maybe they all haven't come to life yet..only ran it for about 3 minutes at 2-3K rpm.

Every so often you could hear it run normally and it was smooth and sounded fine, but the misfiring and constant pedal pump are obviously not normal...plug wires checked and they are on the right plug.

I used a Casper cam tool to set sensor....we do NOT have the factory boost solenoid hooked up yet, but I didn;t think that would cause my problem. I am still not real familiar with all the hookups and hose routings, but everything appears to be hooked up and no noticeable vacuum leaks that would do this.

I know it's hard to diagnose a car without being there, but any gross errors come to mind when seeing these symptoms.??

Car has been sitting for 2 years with engine out; all electrical seems to be working fine; Scanmaster lights up and gives readings.

edit: just remembered the chip in the car was for 60# injectors and I have #36 in there now; I will swap chip in the morning; do you think this could cause all the comotion??

Thanks for any input,

Bob

 

[earlbrown]

Hello,


Injectors have been sitting in the shop for about two years; worked fine last time they were in the car, but I thought maybe they all haven't come to life yet..only ran it for about 3 minutes at 2-3K rpm.

There's your problem. (or at least one of them)

 

[wb's87]

Hello,

Just got one of our engine rebuild projetcs started tonight. Good oil pressure and quiet running, BUT....I have to pump the pedal to keep it running..it won't run if I let off pedal or hold pedal steady. It's also backfiring slightly once in a while. Reminds me of a carb'd car with a huge vacuum leak, like you left vacuum plug out of manifold under carb, but we can't find any large holes.

Injectors have been sitting in the shop for about two years; worked fine last time they were in the car, but I thought maybe they all haven't come to life yet..only ran it for about 3 minutes at 2-3K rpm.

Every so often you could hear it run normally and it was smooth and sounded fine, but the misfiring and constant pedal pump are obviously not normal...plug wires checked and they are on the right plug.

I used a Casper cam tool to set sensor....we do NOT have the factory boost solenoid hooked up yet, but I didn;t think that would cause my problem. I am still not real familiar with all the hookups and hose routings, but everything appears to be hooked up and no noticeable vacuum leaks that would do this.

I know it's hard to diagnose a car without being there, but any gross errors come to mind when seeing these symptoms.??

Car has been sitting for 2 years with engine out; all electrical seems to be working fine; Scanmaster lights up and gives readings.

edit: just remembered the chip in the car was for 60# injectors and I have #36 in there now; I will swap chip in the morning; do you think this could cause all the comotion??

Thanks for any input,

Bob

Without a doubt. The 60# chip is the culprit. I changed injectors one time and forgot to change the chip. I had the exact symptoms you are describing.


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[Bob Davi]

Ok..problem was the chip. I had one that was cut for 36# injectors and the TA-49 , but not for larger 212/212 cam,.... but it's definitely running much closer to normal. All I need to do now is get all injectors cleaned up and awake...I can hear it getting better as I run it. Maybe a few cans of SeaFoam/Techron. I'll order a new chip on Monday.

Then put in neutral, hold it to the floor and drop in drive, right??? Isn't that the preferred break-in procedure??

Thanks for the input

 

[vacuum 6]

Put some boost to the rings before it's too late.


WB

 

[Bob Davi]

Rough running appears to be gone. I took car out tonite for some road miles. Ran it about 45 minutes' filled alky tank and did some mild pulls to about 14# boost. Engine ran solid, 175 degrees water, oil pressure about 15 hot and instant rise when gas pedal touched, 45 cruise and 60 WOT...perfect in my book for 5W30.

Tranny shifts firm with stock D-5 but no lock-up; I think I have an issue with the shifter linkage (not the cable) as it's a little sloppy...I plan to check it out tomorrow.

Anyway, the dreaded break-in of the flat tappet hydraulic 212/212 seems to be successful and the car cruises nice at about 100mph; also sounds good with nothing behind the factory downpipe,; so.... first full Buick six-banger engine build looks like a success. Two more to go....getting ready for Power Tour with my sons.

Car would be real nice with mild a converter upgrade.............

Thanks to all those I have bothered with phone calls calls and PM's about how to make this work.

Bob

 

[wb's87]

Rough running appears to be gone. I took car out tonite for some road miles. Ran it about 45 minutes' filled alky tank and did some mild pulls to about 14# boost. Engine ran solid, 175 degrees water, oil pressure about 15 hot and instant rise when gas pedal touched, 45 cruise and 60 WOT...perfect in my book for 5W30.

Tranny shifts firm with stock D-5 but no lock-up; I think I have an issue with the shifter linkage (not the cable) as it's a little sloppy...I plan to check it out tomorrow.

Anyway, the dreaded break-in of the flat tappet hydraulic 212/212 seems to be successful and the car cruises nice at about 100mph; also sounds good with nothing behind the factory downpipe,; so.... first full Buick six-banger engine build looks like a success. Two more to go....getting ready for Power Tour with my sons.

Car would be real nice with mild a converter upgrade.............

Thanks to all those I have bothered with phone calls calls and PM's about how to make this work.

Bob

I'm doing the power tour also. Where are you located? Maybe we can hook up? Im in western NY.


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[Bob Davi]

Hello WB,

We're in Gainesville, Texas..about 50 north of Dallas/Ft Worth. Our current "plan" is to drive to St. Louis on June 6th , meet the tour and some other buddies on Monday the 8th, then drive at least two days, see how much "fun" we're having, then decide to continue with Tour or head home. Hope to have 2-3 Buicks, one '67 442, and a possible '67 Chevelle....lots to do to make that happen, but we're gonna try.

We'll look for you....Keep in touch,

Bob

 

[Chuck Leeper]

New build, some miles on it...Now, cut the oil filter open, and see what's there.