3.8 HARD Cold starts..Need Help please

[O.P]

I have an '89 Bonneville, 3.8 that has been giving me the hardest time when the weather is cool (70 and below). It turns over and makes a "backfire" noise. It may take me several successive tries before it sputters and turns off, then gradually the car stays on. Once the car is warm it has no problem starting. I have replace the Coolant temp sensor twice, Temperature switch, Idle air control, Camshaft sensor, Throttle position sensor (and adjusted it to .4). It has fuel in the fuel rail and pressure seems ok. New fuel pump. I can't help to believ that it is a $60 part somewhere that I am over looking. The car is still giving me the CTS code and TPS low voltage. Please help. Thanks in advance

[Creative]

I don't know if they are like to buick's but it might be the crankshaft posistion sensor (( three or four wired sensor right behind the harmonic balancer on the right hand side usally with a nice plastic cover over it to keep the dirt out )) if one outta the two Hall sensors in it are working the car will have starting problems right from not starting to hard starts, leading to lot's of problems when it's cold out right upto starter damage ... if the sensor is not working right it'll allow the computer to adjust the timeing by as much as 50 deg this can make starting fun and can cause backfireing and other problems .... and if your useing a 253 ECM it's a four wire sensor and they are only a few mins to change once you pull the balancer off ((( there's the fun part pullers and 15/16 wrench and some thing to stop it from turning ..))) and brand new they should only be like $40 CDN .....

[O.P]

Could it be the fuel pressure regulator?

[O.P]

I put a new fuel pressure regulator on and it still has the problem.I'm sure someone has had this problem before. It is giving me ses code 14 which is coolant temp sensor, which I have replace 2x. Your help is appreciated.

[int_53185]

Could be something as simple as a bad spark plug wire...sometimes engine codes can be misleading...the systems on an engine are interrelated and often a code in one area of an engine points to a problem with another area.....good luck

[Creative]

Try this pull off your coil pack (( whole module )) and sand the back of it down and sand down the engine mount and put a thin coat of antiseize on it and bolt it down, the Aluminum to Aluminum contacts will corrode and Aluminum Oxide is a great insulator and a bad gound on the coil module will cause all sorts of problems but once it warms up and the aluminum expands enough it make's a OK ground, and if it's a hard part to take off (( some where a pain getting wrenchs under them )) just scratch into the Aluminum base and ground it as a test and have some one try starting it while you hold the ground wire on .... And see if it works ....... Bad grounds are a huge problem on most GM distrubtorless setups ...

[O.P]

Thx Creative I will try that and get back w/ you
OP

[bubbabowtie]

i have a realated problem to that mine a 92 bonneville w/3800 has a hard time starting when hot tho.just touch the foot feet and it takes off anyone have feedback that could help, occasionaly it will have a eratic ideal and stall, but it restarts right away and dont miss a beat

[BonneMeMn]

The 3800 is a Buick made engine regardless of what car it's in. Check all the contacts on the ICM like suggested, and maybe take a look at your Fuel injectors, and the o rings.

[bubbabowtie]

i was in the stalls at running temp. thread w/ red death and i posted that it was the mat sensor was unplugged thanks for all the help
bubbabowtie

[bubbabowtie]

what i dont get is that i got a 23,31, and a 58 code ,in my book it dont show a 58 code tho, but it straightend out thanks again
bubbabowtie