I,ve got a '94 Suz. Sidekick that has a 16 valve engine. Tuned up, new fuel filter, new TPS, new fuel reg., timing adj., new fuel pump, cleaned and sealed tank, new pick-up screen, (tank was rusted and drop tube screen was plugged), but it still bogs and runs so poorly I can't drive it up a small incline to get it in the garage.
However, if I pinch the fuel regulator return hose with vicegrips and get the fuel presure up to 50 PSI at the injector rail, it runs just fine!!!! You don't suppose all four injectors have plugged up screens all the same so it runs smooth at 50 PSI but will only barely pull itself at 40#s presure.
WHAT COULD MAKE IT NOT RUN LIKE THIS?
new fuel pressure reg with a bad diaphragm, id do a vacuum leak down on it before condeming a new part. (besides you have perfect fuel pressure why suspect it?)
i think iampbdb analysis is spot on,
rusty tank , clogged fuel filter, and now the 10 micron screens are all clogged in the 4 injectors.
send the injectors to witchhunter.com $18 each ( cames back with before and after flow rates and they are honest people and data is spot on )
if it has no power at 30psi cold ,then the injectors are clogged.
(it could be a bad MAF or tps (new) ,but I dont think so)
that is my best guess at this problem, hope it helps you get kicking.
cheers.
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91'-8v,2dr,4wd,Conv. Market#E03
My server has Engine Repair proc/data. Check it out.
do not put new clean injectors in the car , unless a fresh fuel filter is added.
(im sure you put one in and forgot to mention it.)
I presume tank is clean and all rust is out of tank and lines and filter.
then clean injectors.
( there might be a way for you to clean the injector screens but I do not know how to do it , some one here might have a trick?)
witchhunter , my guess they backwash them, reversing the flow.
but that is speculation.
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91'-8v,2dr,4wd,Conv. Market#E03
My server has Engine Repair proc/data. Check it out.
I did put a new fuel filter near the beginning of this episode. I haven't tried a MAF though. The dealer who I got it from had it on his lot for 5 years!
I think I'll send the injectors in. I haven't replaced the MAF, though. It sat on the dealers lot for 5 years. Injector screens could've dried out and plugged up under those circumstances, I suppose. I've adjusted the TPS to a tee and it seems to do it's job. You'd think, with the return line pinched, and running on 50 PSI, if it was TPS it would still hesitate. But I'm slightly fuzzy about symptom possibilities from a bad MAF. Also, odd there's no engine light.
Thanks for the ideas
if forgot to say the pinched hose test puts a huge stress on pump ( the shunt test should be limited to 10 seconds, I just shows you what your over head is and the true power of pump, mine hits 65psi) im sure you know all that, but others, might get carried away......
id do not suspect tps. nor maf, as bad. ( the TPS just give slight enrich on a fast foot, it can not stop WOT fast run)
but the MAF must get the air flow correct. ( key part this is on 16v engine)
both can be tested with a voltmeter. It is not hard,if you need wire colors i have them.
tps varies key on, from 1 to 4v.
and so does MAF running hot. ( can be tested easier with automatic in drive and brakes set simulating huge load)
we can measure them easy, no need to swap them, too much $$$
5years sitting, id bet the injectors are gummed up big time.
It will run again.
cheers.
PS: I do love your variable fuel pump test, it is very cool, as it does get a good data point,(fuel starvation)
__________________ http://carfix.stufftoread.com/
click me.
91'-8v,2dr,4wd,Conv. Market#E03
My server has Engine Repair proc/data. Check it out.
'94 Sidekick only runs with reg. hose pinched
Linear Mode
