timing issues/flat spot at 2500rpm on loyale

[loyalewithcheese]

hey all, me again.

 

so i got the loyale smog'ed yesterday and the jerk at the chevron said it failed because the timing was off and was set to 29°BTC. his english sucked so i gathered that he said it was off spec and that that setting could make it prone to pinging. so he set to 20° and it passed BUT now it seems even more gutless than before and has a nasty flat spot around 2500rpm which is annoying because i live in the mountians and climb hills all day.

 

the mystery is afterwards he said he pulled some plug (a green one near the driver's firewall) to "bypass the computer" after three attempts to understand the purpose of this i gave up. the communication just wasn't happening.

 

so can anyone guess as to what his purpose of bypassing the computer? should i recheck the timing and adjust to something else? anyone have any recommended setting and could you pretty-please provide me with some instructions on setting the timing on this car? i've set timing before, but mostly just static timing on old vw's i get the concept, but i'm just not good at it. i have a timing light and the will.

 

also is there anything else i should look for that is causing this flat spot at 2500rpm?

 

thanks

droo

[[HTi]Johnson]

That green connector DOES bypass something. I know you connect them together to time the car. Then disconnect them when you are done. There should be a black connector by them, that shuold be disconnected too. That is to read codes on the PCM LED(Light). Do a search, you'll find the point of that.

Connecting the green connectors is like plugging the vacuum advance on a mechanical Distributor.

If the green connector is connected, you car is running in a mode that isn't meant for driving. I believe that the computer won't adjust the fuel to air ratio...i'll stop talking now...probably way off track. But I DO know those connectors.

[subynut]

Accually, HTI, you're pretty much on track.

loyalewithcheese:

Does your car have MPFI or SPFI? If it's MPFI there will be a pair of green and a pair of black. If it's SPFI then they're White and green. Both should be disconnected during driving. Like HTI said, the green ones are used to set the timing and check the system compnents by the dealer. The other ones are used to read the stored codes when the CEL comes on in the event of an error.

As far as timing, from what I've played around with the timing on my roo, I think you can pretty much set the timing to where you want your max power to be. If you go too far advanced, you run the risk of pinging and possible burnt intake valves. Personally, running at 29" won't hurt it, if your not experiencing pinging.

I find it intresting that you have a flat spot around 2500 with the timing set at 20" whereas it wasn't there when it was set at 29". Hummmm gonna hafta try that on my roo. I'm currently running about 16" which moved my peek power further up the RPMs; not sure where, but it's too far for the cams I got in there.

[loyalewithcheese]

Accually, HTI, you're pretty much on track.

loyalewithcheese:

Does your car have MPFI or SPFI? If it's MPFI there will be a pair of green and a pair of black. If it's SPFI then they're White and green. Both should be disconnected during driving. Like HTI said, the green ones are used to set the timing and check the system compnents by the dealer. The other ones are used to read the stored codes when the CEL comes on in the event of an error.

As far as timing, from what I've played around with the timing on my roo, I think you can pretty much set the timing to where you want your max power to be. If you go too far advanced, you run the risk of pinging and possible burnt intake valves. Personally, running at 29" won't hurt it, if your not experiencing pinging.

I find it intresting that you have a flat spot around 2500 with the timing set at 20" whereas it wasn't there when it was set at 29". Hummmm gonna hafta try that on my roo. I'm currently running about 16" which moved my peek power further up the RPMs; not sure where, but it's too far for the cams I got in there.

 

not sure if it's MPFI or SPFI, i'll have to look. there did seem to be a flat spot before, but it just seems much more pronounced now. i'll look at just tuning up with filter changes, etc. taking it in next week to get the A/C looked at/recharged i may just get my mechanics to look at it if a tune up doesn't help.

 

thanks for the advice. if anyone has any other suggestions or know of common ailments let me know.

 

cheers

droo

[Petersubaru]

I would think your problem would be related to the timing not coming on fast enough at a certain RPM...I am having that problem now with my 86 which still has a vac pot on the distributor...I checked to see if the inside of the dist. moves freely which it does , only to find out that the vac pot has a leak which retards the timing for normal driving...on the hand if you have a turbo, retarding the timing in the upper RPM's would be beneficial when you hammer it down

[UrbanSoobieCowboy]

Just a note...I recently bought a 93 Loyale cheap (needed clutch replacement) and drove it for a day. It had no power to speak of and since I was already suspicious of the timing (the distributor was advanced as far as it could be turned) it took the front apart. The person that had changed the timing belts had put the outer crank belt sprocket back on 180 degrees off & backwards, causing the pass. side belt to have some play in it and not allowing the timing marks to be lined up exactly.

[NorthWet]

I wonder whether the mechanic got things a little backwards. I wonder if he checked/adjusted the timing while the green plugs were disconnected, then reconnected them to send you on your way. If this were the case, you probably had close-to-correct timing when you drove in and messed up timing when you left.

 

Otherwise, the first things I would check are tune-up stuff: New plugs and wires, TIMING , fuel filter... that kind of stuff. I realize that you probagbly took care of this stuff before emissions testing, but thought that I should mention it anyways.