88 bonneville cranks but wont start
#1
Member
Posts like a V-Tak
Thread Starter
88 bonneville cranks but wont start
hello to all, - esp. them as may be able to help : )
I've got a 1988 bonneville 3.8 (vin 3) with 109,000 miles.
I replaced a MAF sensor that was intermittenly showing an error 34.
Car ran really rough when light was on, but light only came on for a few min once a month or so, then went out.
Finally the light stayed on, so I got a new MAF and light went out & car ran well.
Next day, car ran really rough for a couple blocks, then quit with no error light.
Checked cam & crank sensors and spark and saw a bit of fuel pressure (but no tester, so not sure), but I did try starting it on starting fluid and got nothing.
I'm really old & half crippled up, so it took me a few days to get the timing chest open to see if cam timing was off, but it is OK.
Will take another few days to get all back together for more tests, but I have no idea what to test next.
Did I short something while doing original test on MAF sensor???
Put in my spare coil pack when doing tests before checking cam timing.
Anything else I should check before buttoning up the timing chest???
I've got a 1988 bonneville 3.8 (vin 3) with 109,000 miles.
I replaced a MAF sensor that was intermittenly showing an error 34.
Car ran really rough when light was on, but light only came on for a few min once a month or so, then went out.
Finally the light stayed on, so I got a new MAF and light went out & car ran well.
Next day, car ran really rough for a couple blocks, then quit with no error light.
Checked cam & crank sensors and spark and saw a bit of fuel pressure (but no tester, so not sure), but I did try starting it on starting fluid and got nothing.
I'm really old & half crippled up, so it took me a few days to get the timing chest open to see if cam timing was off, but it is OK.
Will take another few days to get all back together for more tests, but I have no idea what to test next.
Did I short something while doing original test on MAF sensor???
Put in my spare coil pack when doing tests before checking cam timing.
Anything else I should check before buttoning up the timing chest???
#2
Senior Member
True Car Nut
not sure what you are saying, with the cam timing. there is a magnet and a sensor, are both of those good? what about the crank sensor? i would check the connector for the maf signal too pull on the wires to check for looseness and inspect for corrosion.
#3
Member
Posts like a V-Tak
Thread Starter
did all the MAF testing for conns before replacing it, and as soon as it was replaced the error light went out
checked and got 6 crank signals for each cam signal before opening timing chest
not sure how to test a magnet except look for the good signal I got before opening, and then while chest was open a screw driver will stick to it
was pretty sure it was the nylon sprocket on the cam that went bad, but now I see that I put a steel sprocket on last time it went bad (forgot that after last 12 years since)
timing marks from crank to cam are lined very nicely
checked and got 6 crank signals for each cam signal before opening timing chest
not sure how to test a magnet except look for the good signal I got before opening, and then while chest was open a screw driver will stick to it
was pretty sure it was the nylon sprocket on the cam that went bad, but now I see that I put a steel sprocket on last time it went bad (forgot that after last 12 years since)
timing marks from crank to cam are lined very nicely
#4
Senior Member
True Car Nut
if its wired like the new ones, i think i would look at the wiring to the icm/coil pack next then. i think the cam and crank sensors go though it and that could make it not start
#5
Member
Posts like a V-Tak
Thread Starter
yes, this car has low miles, as I rarely leave the house these days, but the wiring is still aging & a bit brittle
before opening the timing chest, I was thinking that I may have broken a wire somewhere while testing the MAF, or shorted something out
now that I see the timing is right, I'm thinking that again, but not sure how to test things like ESM (electronic spark control module) or some other things that may be bad
the ECM (electronic control module) seems to be happily reporting a code 12
before opening the timing chest, I was thinking that I may have broken a wire somewhere while testing the MAF, or shorted something out
now that I see the timing is right, I'm thinking that again, but not sure how to test things like ESM (electronic spark control module) or some other things that may be bad
the ECM (electronic control module) seems to be happily reporting a code 12
#6
Member
Posts like a V-Tak
Thread Starter
things don't get no easier : (
autozone ordered the wrong gasket set, so now I'm stuck till tomorrow
also tried two diff adapters for my compression gauge in order to fit it deep into that narrow area where the plug fits - neither works, so I've got to try to drill out an old plug body & tap it to fit the gauge
then maybe tomorrow I can get it buttoned up and do more testing if anyone has any suggestions on what/how to test
autozone ordered the wrong gasket set, so now I'm stuck till tomorrow
also tried two diff adapters for my compression gauge in order to fit it deep into that narrow area where the plug fits - neither works, so I've got to try to drill out an old plug body & tap it to fit the gauge
then maybe tomorrow I can get it buttoned up and do more testing if anyone has any suggestions on what/how to test
#8
Member
Posts like a V-Tak
Thread Starter
cam & crank were lined up just right
on the plus side, I broke the porcelain out of an old spark plug & threaded the inside of its body - now I have a nice adapter for my compression gauge that I know will fit into that deep channel the plug goes in : )
#9
Member
Posts like a V-Tak
Thread Starter
well, been two days getting this thing back together - my poor back just won't take all this bending-kind of work
not ready to try it yet, but while getting ready to put in crank sensor, I noticed a ding in the plastic where some kind of road debris must have hit it & a bit of copper showing thru (had proper gap at the balancer vanes tho)
before opening timing chest, I got three signals from that sensor for each turn of the crank as was expected when turning crank by hand with a 3 vane balancer, but am now wondering if at cranking speed that sensor could get erratic
bought a new one, so hoping to see some good tomorrow when I try it again
not ready to try it yet, but while getting ready to put in crank sensor, I noticed a ding in the plastic where some kind of road debris must have hit it & a bit of copper showing thru (had proper gap at the balancer vanes tho)
before opening timing chest, I got three signals from that sensor for each turn of the crank as was expected when turning crank by hand with a 3 vane balancer, but am now wondering if at cranking speed that sensor could get erratic
bought a new one, so hoping to see some good tomorrow when I try it again
#10
Member
Posts like a V-Tak
Thread Starter
all back together with the new crank sensor (that I couldn't really afford)
still won't start - cranks a lot then stumbles a couple times without really turning on its own - starting fluid doesn't help either
I scratched a mark on the harmonic balancer about at the key way which looks to be maybe 30 degrees BTDC and a likely place for cyl #1 to fire.
Used timing light while cranking and expected to see the mark about straight up, but it was way out between 1 & 2 o'clock - this seems way advanced to me, but maybe someone here knows.
anyone?
still won't start - cranks a lot then stumbles a couple times without really turning on its own - starting fluid doesn't help either
I scratched a mark on the harmonic balancer about at the key way which looks to be maybe 30 degrees BTDC and a likely place for cyl #1 to fire.
Used timing light while cranking and expected to see the mark about straight up, but it was way out between 1 & 2 o'clock - this seems way advanced to me, but maybe someone here knows.
anyone?